DBMS assignment

DBMS assignment

MITS4003 Database Systems

 

Take Home Exercise – 2 of Lesson – 2

 

June 2018 Task 1: E-R Diagram

 

 

MITS4003 Exercise 2

Copyright © 2015-2018 VIT, All Rights Reserved. 2

2.1 Construct an E-R diagram for a car insurance company whose customers own one or more cars each. Each car has associated with it zero to any number of recorded accidents. Each insurance policy covers one or more cars, and has one or more premium payments associated with it. Each payment is for a particular period of time, and has an associated due date, and the date when the payment was received. What is a model?

2.2 Consider a database used to record the marks that students get in different exams of different course offerings (sections).

a. Construct an E-R diagram that models exams as entities, and uses a ternary relationship, for the database.

b. Construct an alternative E-R diagram that uses only a binary relationship between student and section. Make sure that only one relationship exists between a particular student and section pair, yet you can represent the marks that a student gets in different exams.

Task 2: Problems 2.3 A weak entity set can always be made into a strong entity set by adding to its attributes the primary- key attributes of its identifying entity set. Outline what sort of redundancy will result if we do so.

2.4 An E-R diagram can be viewed as a graph. What do the following mean in terms of the structure of an enterprise schema?

a. The graph is disconnected.

b. The graph has a cycle.

 
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Illustrated Excel 2016 | Module 12: assignment Help

Illustrated Excel 2016 | Module 12: assignment Help

Documentation

Illustrated Excel 2016 | Module 12: SAM Project 1a
The Spice Market
ANALYZING DATA WITH PIVOTTABLES
Author: Latrice Reaves
Note: Do not edit this sheet. If your name does not appear in cell B6, please download a new copy of the file from the SAM website.

Orders

Spice Pack Orders
Customer Region Order Number Date Product Quantity Unit Price Discount Discounted Price Total Quantity per Region
SP1 Northwest 500 1/1/18 Mediterranean 30 $19.25 5.0% $18.29 $548.63 Midwest 227
SP5 Northwest 554 1/10/18 Starter Set 85 $12.50 5.0% $11.88 $1,009.38 Northeast 213
SP2 Northeast 502 2/1/18 Grill Set 36 $19.75 7.5% $18.27 $657.68 Northwest 212
SP2 Northeast 556 2/14/18 Starter Set 30 $12.50 7.5% $11.56 $346.88 Southeast 75
SP3 Southeast 504 3/1/18 Starter Set 45 $12.50 4.0% $12.00 $540.00 Southwest
SP7 Southwest 558 3/15/18 Grill Set 25 $19.75 5.0% $18.76 $469.06
SP4 Midwest 506 4/3/18 Grill Set 60 $19.75 10.0% $17.78 $1,066.50
SP12 Midwest 530 4/7/18 Curry Set 28 $18.50 5.0% $17.58 $492.10
SP5 Northwest 508 5/6/18 Holiday 40 $11.75 4.0% $11.28 $451.20
SP5 Northwest 532 5/19/18 Grill Set 32 $19.75 4.0% $18.96 $606.72
SP6 Northeast 510 6/1/18 Starter Set 25 $12.50 5.0% $11.88 $296.88
SP6 Northeast 535 6/14/18 Chile Set 45 $17.50 5.0% $16.63 $748.13
SP9 Northeast 534 6/20/18 Chile Set 52 $17.50 2.5% $17.06 $887.25
SP10 Midwest 536 6/25/18 Chile Set 19 $17.50 4.0% $16.80 $319.20
SP7 Southeast 515 7/18/18 Starter Set 10 $12.50 5.0% $11.88 $118.75
SP3 Southwest 537 7/22/18 Chile Set 35 $17.50 4.0% $16.80 $588.00
SP4 Midwest 514 8/1/18 Mediterranean 45 $19.25 10.0% $17.33 $779.63
SP12 Midwest 539 8/10/18 Curry Set 40 $18.50 5.0% $17.58 $703.00
SP4 Southwest 538 8/30/18 Curry Set 55 $18.50 10.0% $16.65 $915.75
SP1 Northwest 516 9/5/18 Mediterranean 25 $19.25 5.0% $18.29 $457.19
SP2 Northeast 518 10/7/18 Grill Set 25 $19.75 7.5% $18.27 $456.72
SP11 Southeast 520 11/12/18 Grill Set 20 $19.75 2.5% $19.26 $385.13
SP8 Midwest 552 12/16/18 Starter Set 35 $12.50 2.5% $12.19 $426.56

Products

Product Region Average Quantity Sum of Discount Average Discounted Price
Mediterranean Midwest 45 0.1 17.325
Northwest 28 0.1 18.2875
Starter Set Midwest 35 0.025 12.1875
Northwest 85 0.05 11.875
Northeast 28 0.125 11.71875
Southeast 28 0.09 11.9375
Grill Set Midwest 60 0.1 17.775
Southwest 25 0.05 18.7625
Northwest 32 0.04 18.96
Northeast 31 0.15 18.26875
Southeast 20 0.025 19.25625
Curry Set Midwest 34 0.1 17.575
Southwest 55 0.1 16.65
Holiday Northwest 40 0.04 11.28
Chile Set Midwest 19 0.04 16.8
Southwest 35 0.04 16.8
Northeast 49 0.075 16.84375
Grand Total 37 1.25 15.9536413043

Monthly Sales

Product (All)
Sum of Quantity
Midwest Southwest Northwest Northeast Southeast Grand Total
Jan 115 115
Feb 66 66
Mar 25 45 70
Apr 88 88
May 72 72
Jun 122 122
Jul 19 35 10 64
Aug 85 55 140
Sep 25 25
Oct 25 25
Nov 20 20
Dec 35 35
Grand Total 227 115 212 213 75 842

Region PivotChart

Product Order Amounts per Region

Starter Set Southwest Southeast 540 Grill Set Southwest Southeast 469.0625

 

 

 

 

Regions

Date Mar
Total Order Amounts
Starter Set Grill Set Grand Total
Southwest $ 469.06 $ 469.06
Southeast $ 540.00 $ 540.00
Grand Total $ 540.00 $ 469.06 $ 1,009.06

Discounted Price

Average of Discounted Price Column Labels
Row Labels Chile Set Curry Set Grill Set Holiday Mediterranean Starter Set Grand Total
500 18.29 18.29
SP1 18.29 18.29
502 18.27 18.27
SP2 18.27 18.27
504 12.00 12.00
SP3 12.00 12.00
506 17.78 17.78
SP4 17.78 17.78
508 11.28 11.28
SP5 11.28 11.28
510 11.88 11.88
SP6 11.88 11.88
514 17.33 17.33
SP4 17.33 17.33
515 11.88 11.88
SP7 11.88 11.88
516 18.29 18.29
SP1 18.29 18.29
518 18.27 18.27
SP2 18.27 18.27
520 19.26 19.26
SP11 19.26 19.26
530 17.58 17.58
SP12 17.58 17.58
532 18.96 18.96
SP5 18.96 18.96
534 17.06 17.06
SP9 17.06 17.06
535 16.63 16.63
SP6 16.63 16.63
536 16.80 16.80
SP10 16.80 16.80
537 16.80 16.80
SP3 16.80 16.80
538 16.65 16.65
SP4 16.65 16.65
539 17.58 17.58
SP12 17.58 17.58
552 12.19 12.19
SP8 12.19 12.19
554 11.88 11.88
SP5 11.88 11.88
556 11.56 11.56
SP2 11.56 11.56
558 18.76 18.76
SP7 18.76 18.76
Grand Total 16.82 17.27 18.55 11.28 17.97 11.90 15.95

Product Pricing

Product Pricing PivotTable
Row Labels Sum of Quantity Average of Unit Price
Mediterranean 100 $ 19.25
SP1 55 $ 19.25
SP4 45 $ 19.25
Starter Set 230 $ 12.50
SP5 85 $ 12.50
SP2 30 $ 12.50
SP3 45 $ 12.50
SP7 10 $ 12.50
SP6 25 $ 12.50
SP8 35 $ 12.50
Grill Set 198 $ 19.75
SP5 32 $ 19.75
SP2 61 $ 19.75
SP7 25 $ 19.75
SP4 60 $ 19.75
SP11 20 $ 19.75
Curry Set 123 $ 18.50
SP4 55 $ 18.50
SP12 68 $ 18.50
Holiday 40 $ 11.75
SP5 40 $ 11.75
Chile Set 151 $ 17.50
SP3 35 $ 17.50
SP6 45 $ 17.50
SP9 52 $ 17.50
SP10 19 $ 17.50
Grand Total 842 $ 16.89
 
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Scientific Computing I-APPROXIMATIONS AND ROUND-OFF ERRORS Assignment Help

Scientific Computing I-APPROXIMATIONS AND ROUND-OFF ERRORS Assignment Help

1.Evaluate

e power−5

using two approaches

e power−x=1–x+xpower2/2−xpower3/3!+……

and

epower−x=1/e power x=1/(1+x+(xpower2/2)+(xpower3/3!))+……

and compare with the true value of

6.737947×10power−3.

Use 20 terms to evaluate each series and compute true and approximate relative errors as terms are added.

2.The derivative of f(x)=1/(1-3x power2) is given by

6x/(1=3x power 2)whole power2

Do you expect to have difficulties evaluating this function at x =0.577? Try it using 3- and 4-digit arithmetic with chopping.

3.(a)Evaluate the polynomial

y=xpower 3-5xpower2+6x+0.55

at x =1.37. Use 3-digit arithmetic with chopping. Evaluate thepercent relative error.

(b)Repeat(a) but express as

y=((x-5)x+6)x=0.55

Evaluate the error and compare with part(a).

 

4.Use 5-digit arithmetic with chopping to determine the roots of the following equation with Eqs. (3.12) and (3.13)

xpower2-5000.002x+10

Compute percent relative errors for your results.

5.The “divide and average” method, an old-time method for approximating the square root of any positive number

a, can be formulated as

x=(x+(a/x))/2

Write a well-structured function to implement this algorithm basedon the algorithm outlined in Fig. 3.3

 
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Computer Science homework help

Computer Science homework help

8.  A script to create a small table with 3 rows for recovery testing.

CREATE TABLE LOG (

Id int primary key not null,

UserID int,

TimeStamp DateTime

)

Insert into LOG (1,1,2019-07-13 10:00:01)

Insert into LOG (2,4,2019-07-13 09:20:01)

Insert into LOG (3,5,2019-07-13 08:50:01)

9.  Backup and recovery commands for Recovery testing using export/import and RMAN utilities.

rman

RMAN> OnlineShopping

RMAN> register database

RMAN> RESYNC OnlineShopping;

10.  Design and backup/recovery commands for your test.

RMAN> backup database;

 

Starting backup at 12-JUL-19

using target database control file instead of recovery catalog

allocated channel: ORA_DISK_1

 

channel ORA_DISK_1: SID=198 device type=DISK

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

 

input datafile file number=00001 name=D:\APP1\SUNTYADA\ORADATA\ORCL\SYSTEM01.DBF

input datafile file number=00002 name=D:\APP1\SUNTYADA\ORADATA\ORCL\SYSAUX01.DBF

input datafile file number=00005 name=D:\APP1\SUNTYADA\ORADATA\ORCL\EXAMPLE01.DBF

input datafile file number=00003 name=D:\APP1\SUNTYADA\ORADATA\ORCL\UNDOTBS01.DBF

input datafile file number=00004 name=D:\APP1\SUNTYADA\ORADATA\ORCL\USERS01.DBF

 

channel ORA_DISK_1: starting piece 1 at 12-JUL-19

channel ORA_DISK_1: finished piece 1 at 12-JUL-19

 

piece handle=D:\APP1\SUNTYADA\FLASH_RECOVERY_AREA\ORCL\BACKUPSET\2014_10_05\O1_MF_NNNDF_TAG20191005T162412_B328TXQG_.BKP tag=TAG20141005T162412 comment=NONE

 

channel ORA_DISK_1: backup set complete, elapsed time: 00:04:27

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

 

including current control file in backup set

including current SPFILE in backup set

 

channel ORA_DISK_1: starting piece 1 at 12-JUL-19

channel ORA_DISK_1: finished piece 1 at 12-JUL-19

 

piece handle=D:\APP1\SUNTYADA\FLASH_RECOVERY_AREA\ORCL\BACKUPSET\2019_07_12\O1_MF_NCSNF_TAG20191005T162412_B3293806_.BKP tag=TAG20191005T162412 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:04

 

Finished backup at 12-JUL-19

Restore:

Starting restore at 12-JUL-19

using channel ORA_DISK_1

 

List of Backup Sets

===================

BS Key Type LV Size       Device Type Elapsed Time Completion Time

——- —- — ———- ———– ———— —————

4       Full   1.39G     DISK       00:04:23     12-JUL-19

BP Key: 4   Status: AVAILABLE Compressed: NO Tag: TAG20191005T162412

Piece Name: D:\APP1\SUNTYADA\FLASH_RECOVERY_AREA\ORCL\BACKUPSET\2019_07_12\O1_MF_NNNDF_TAG20191005T162412_B328TXQG_.BKP

List of Datafiles in backup set 4

File LV Type Ckp SCN   Ckp Time Name

—- — —- ———- ——— —-

1       Full 9684060   12-JUL-19 D:\APP1\SUNTYADA\ORADATA\ORCL\SYSTEM01.DBF

2       Full 9684060   12-JUL-19 D:\APP1\SUNTYADA\ORADATA\ORCL\SYSAUX01.DBF

3       Full 9684060   12-JUL-19 D:\APP1\SUNTYADA\ORADATA\ORCL\UNDOTBS01.DBF

4       Full 9684060   12-JUL-19 D:\APP1\SUNTYADA\ORADATA\ORCL\USERS01.DBF

5       Full 9684060   12-JUL-19 D:\APP1\SUNTYADA\ORADATA\ORCL\EXAMPLE01.DBF

 

List of Archived Log Copies for database with db_unique_name ORCL

=====================================================================

Key     Thrd Seq     S Low Time

——- —- ——- – ———

367     1   366     A 02-OCT-14

Name: D:\APP1\SUNTYADA\FLASH_RECOVERY_AREA\ORCL\ARCHIVELOG\2019_07_12\O1_MF_1_366_B32925TJ_.ARC

Media recovery start SCN is 9684060

Recovery must be done beyond SCN 9704654 to clear datafile fuzziness

 

Finished restore at 12-JUL-19

 

11.  Include explanations for what happened during the recovery when import vs. RMAN was used.

RMAN and export both used to backup tables, both commands supports the flashback database but some difference is

· Data Pump Export (expdp) – The export utility is a “logical” backup, usually done by specifying table names which need to be backed up.

· Recovery manager (rman) – RMAN is designed for backup and recovery, it takes the backup of full database.

Rman is more preferable in my opinion for the database.

12.  Flashback recovery commands.

· sqlplus ‘/ as sysdba’

· SQL> alter system set db_recovery_file_dest=’+<FRA Diskgroup>’ SCOPE=spfile;

· SQL> alter system set db_recovery_file_dest_size=100G SCOPE=spfile;

· sqlplus ‘/ as sysdba’

· SQL> shutdown immediate;

· SQL> startup mount;

· If flashback to any previous point in time is required, then turn flashback on using the following command

· SQL> alter database flashback on;

· SQL> alter database open;

· SQL> alter system set db_flashback_retention_target=2880;

· sqlplus ‘/ as sysdba’

· SQL> select name, time,guarantee_flashback_databse from v$restore_point;

· SQL> quit

 
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Python Assignment

Python Assignment

pset5/feedparser.py

“””Universal feed parser Handles RSS 0.9x, RSS 1.0, RSS 2.0, CDF, Atom 0.3, and Atom 1.0 feeds Visit https://code.google.com/p/feedparser/ for the latest version Visit http://packages.python.org/feedparser/ for the latest documentation Required: Python 2.4 or later Recommended: iconv_codec <http://cjkpython.i18n.org/> “”” __version__ = “5.2.1” __license__ = “”” Copyright 2010-2015 Kurt McKee <contactme@kurtmckee.org> Copyright 2002-2008 Mark Pilgrim All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ‘AS IS’ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.””” __author__ = “Mark Pilgrim <http://diveintomark.org/>” __contributors__ = [“Jason Diamond <http://injektilo.org/>”, “John Beimler <http://john.beimler.org/>”, “Fazal Majid <http://www.majid.info/mylos/weblog/>”, “Aaron Swartz <http://aaronsw.com/>”, “Kevin Marks <http://epeus.blogspot.com/>”, “Sam Ruby <http://intertwingly.net/>”, “Ade Oshineye <http://blog.oshineye.com/>”, “Martin Pool <http://sourcefrog.net/>”, “Kurt McKee <http://kurtmckee.org/>”, “Bernd Schlapsi <https://github.com/brot>”,] # HTTP “User-Agent” header to send to servers when downloading feeds. # If you are embedding feedparser in a larger application, you should # change this to your application name and URL. USER_AGENT = “UniversalFeedParser/%s +https://code.google.com/p/feedparser/” % __version__ # HTTP “Accept” header to send to servers when downloading feeds. If you don’t # want to send an Accept header, set this to None. ACCEPT_HEADER = “application/atom+xml,application/rdf+xml,application/rss+xml,application/x-netcdf,application/xml;q=0.9,text/xml;q=0.2,*/*;q=0.1” # List of preferred XML parsers, by SAX driver name. These will be tried first, # but if they’re not installed, Python will keep searching through its own list # of pre-installed parsers until it finds one that supports everything we need. PREFERRED_XML_PARSERS = [“drv_libxml2″] # If you want feedparser to automatically resolve all relative URIs, set this # to 1. RESOLVE_RELATIVE_URIS = 1 # If you want feedparser to automatically sanitize all potentially unsafe # HTML content, set this to 1. SANITIZE_HTML = 1 # ———- Python 3 modules (make it work if possible) ———- try: import rfc822 except ImportError: from email import _parseaddr as rfc822 try: # Python 3.1 introduces bytes.maketrans and simultaneously # deprecates string.maketrans; use bytes.maketrans if possible _maketrans = bytes.maketrans except (NameError, AttributeError): import string _maketrans = string.maketrans # base64 support for Atom feeds that contain embedded binary data try: import base64, binascii except ImportError: base64 = binascii = None else: # Python 3.1 deprecates decodestring in favor of decodebytes _base64decode = getattr(base64, ‘decodebytes’, base64.decodestring) # _s2bytes: convert a UTF-8 str to bytes if the interpreter is Python 3 # _l2bytes: convert a list of ints to bytes if the interpreter is Python 3 try: if bytes is str: # In Python 2.5 and below, bytes doesn’t exist (NameError) # In Python 2.6 and above, bytes and str are the same type raise NameError except NameError: # Python 2 def _s2bytes(s): return s def _l2bytes(l): return ”.join(map(chr, l)) else: # Python 3 def _s2bytes(s): return bytes(s, ‘utf8’) def _l2bytes(l): return bytes(l) # If you want feedparser to allow all URL schemes, set this to () # List culled from Python’s urlparse documentation at: # http://docs.python.org/library/urlparse.html # as well as from “URI scheme” at Wikipedia: # https://secure.wikimedia.org/wikipedia/en/wiki/URI_scheme # Many more will likely need to be added! ACCEPTABLE_URI_SCHEMES = ( ‘file’, ‘ftp’, ‘gopher’, ‘h323’, ‘hdl’, ‘http’, ‘https’, ‘imap’, ‘magnet’, ‘mailto’, ‘mms’, ‘news’, ‘nntp’, ‘prospero’, ‘rsync’, ‘rtsp’, ‘rtspu’, ‘sftp’, ‘shttp’, ‘sip’, ‘sips’, ‘snews’, ‘svn’, ‘svn+ssh’, ‘telnet’, ‘wais’, # Additional common-but-unofficial schemes ‘aim’, ‘callto’, ‘cvs’, ‘facetime’, ‘feed’, ‘git’, ‘gtalk’, ‘irc’, ‘ircs’, ‘irc6’, ‘itms’, ‘mms’, ‘msnim’, ‘skype’, ‘ssh’, ‘smb’, ‘svn’, ‘ymsg’, ) #ACCEPTABLE_URI_SCHEMES = () # ———- required modules (should come with any Python distribution) ———- import cgi import codecs import copy import datetime import itertools import re import struct import time import types import urllib.request, urllib.parse, urllib.error import urllib.request, urllib.error, urllib.parse import urllib.parse import warnings from html.entities import name2codepoint, codepoint2name, entitydefs import collections try: from io import BytesIO as _StringIO except ImportError: try: from io import StringIO as _StringIO except ImportError: from io import StringIO as _StringIO # ———- optional modules (feedparser will work without these, but with reduced functionality) ———- # gzip is included with most Python distributions, but may not be available if you compiled your own try: import gzip except ImportError: gzip = None try: import zlib except ImportError: zlib = None # If a real XML parser is available, feedparser will attempt to use it. feedparser has # been tested with the built-in SAX parser and libxml2. On platforms where the # Python distribution does not come with an XML parser (such as Mac OS X 10.2 and some # versions of FreeBSD), feedparser will quietly fall back on regex-based parsing. try: import xml.sax from xml.sax.saxutils import escape as _xmlescape except ImportError: _XML_AVAILABLE = 0 def _xmlescape(data,entities={}): data = data.replace(‘&’, ‘&amp;’) data = data.replace(‘>’, ‘&gt;’) data = data.replace(‘<‘, ‘&lt;’) for char, entity in entities: data = data.replace(char, entity) return data else: try: xml.sax.make_parser(PREFERRED_XML_PARSERS) # test for valid parsers except xml.sax.SAXReaderNotAvailable: _XML_AVAILABLE = 0 else: _XML_AVAILABLE = 1 # sgmllib is not available by default in Python 3; if the end user doesn’t have # it available then we’ll lose illformed XML parsing and content santizing try: import sgmllib except ImportError: # This is probably Python 3, which doesn’t include sgmllib anymore _SGML_AVAILABLE = 0 # Mock sgmllib enough to allow subclassing later on class sgmllib(object): class SGMLParser(object): def goahead(self, i): pass def parse_starttag(self, i): pass else: _SGML_AVAILABLE = 1 # sgmllib defines a number of module-level regular expressions that are # insufficient for the XML parsing feedparser needs. Rather than modify # the variables directly in sgmllib, they’re defined here using the same # names, and the compiled code objects of several sgmllib.SGMLParser # methods are copied into _BaseHTMLProcessor so that they execute in # feedparser’s scope instead of sgmllib’s scope. charref = re.compile(‘&#(\d+|[xX][0-9a-fA-F]+);’) tagfind = re.compile(‘[a-zA-Z][-_.:a-zA-Z0-9]*’) attrfind = re.compile( r’\s*([a-zA-Z_][-:.a-zA-Z_0-9]*)[$]?(\s*=\s*’ r'(\'[^\’]*\’|”[^”]*”|[][\-a-zA-Z0-9./,:;+*%?!&$\(\)_#=~\'”@]*))?’ ) # Unfortunately, these must be copied over to prevent NameError exceptions entityref = sgmllib.entityref incomplete = sgmllib.incomplete interesting = sgmllib.interesting shorttag = sgmllib.shorttag shorttagopen = sgmllib.shorttagopen starttagopen = sgmllib.starttagopen class _EndBracketRegEx: def __init__(self): # Overriding the built-in sgmllib.endbracket regex allows the # parser to find angle brackets embedded in element attributes. self.endbracket = re.compile(”'([^'”<>]|”[^”]*”(?=>|/|\s|\w+=)|'[^’]*'(?=>|/|\s|\w+=))*(?=[<>])|.*?(?=[<>])”’) def search(self, target, index=0): match = self.endbracket.match(target, index) if match is not None: # Returning a new object in the calling thread’s context # resolves a thread-safety. return EndBracketMatch(match) return None class EndBracketMatch: def __init__(self, match): self.match = match def start(self, n): return self.match.end(n) endbracket = _EndBracketRegEx() # iconv_codec provides support for more character encodings. # It’s available from http://cjkpython.i18n.org/ try: import iconv_codec except ImportError: pass # chardet library auto-detects character encodings # Download from http://chardet.feedparser.org/ try: import chardet except ImportError: chardet = None # ———- don’t touch these ———- class ThingsNobodyCaresAboutButMe(Exception): pass class CharacterEncodingOverride(ThingsNobodyCaresAboutButMe): pass class CharacterEncodingUnknown(ThingsNobodyCaresAboutButMe): pass class NonXMLContentType(ThingsNobodyCaresAboutButMe): pass class UndeclaredNamespace(Exception): pass SUPPORTED_VERSIONS = {”: ‘unknown’, ‘rss090’: ‘RSS 0.90’, ‘rss091n’: ‘RSS 0.91 (Netscape)’, ‘rss091u’: ‘RSS 0.91 (Userland)’, ‘rss092’: ‘RSS 0.92’, ‘rss093’: ‘RSS 0.93’, ‘rss094’: ‘RSS 0.94’, ‘rss20’: ‘RSS 2.0’, ‘rss10’: ‘RSS 1.0’, ‘rss’: ‘RSS (unknown version)’, ‘atom01’: ‘Atom 0.1’, ‘atom02’: ‘Atom 0.2’, ‘atom03’: ‘Atom 0.3’, ‘atom10’: ‘Atom 1.0’, ‘atom’: ‘Atom (unknown version)’, ‘cdf’: ‘CDF’, } class FeedParserDict(dict): keymap = {‘channel’: ‘feed’, ‘items’: ‘entries’, ‘guid’: ‘id’, ‘date’: ‘updated’, ‘date_parsed’: ‘updated_parsed’, ‘description’: [‘summary’, ‘subtitle’], ‘description_detail’: [‘summary_detail’, ‘subtitle_detail’], ‘url’: [‘href’], ‘modified’: ‘updated’, ‘modified_parsed’: ‘updated_parsed’, ‘issued’: ‘published’, ‘issued_parsed’: ‘published_parsed’, ‘copyright’: ‘rights’, ‘copyright_detail’: ‘rights_detail’, ‘tagline’: ‘subtitle’, ‘tagline_detail’: ‘subtitle_detail’} def __getitem__(self, key): ”’ :return: A :class:`FeedParserDict`. ”’ if key == ‘category’: try: return dict.__getitem__(self, ‘tags’)[0][‘term’] except IndexError: raise KeyError(“object doesn’t have key ‘category'”) elif key == ‘enclosures’: norel = lambda link: FeedParserDict([(name,value) for (name,value) in list(link.items()) if name!=’rel’]) return [norel(link) for link in dict.__getitem__(self, ‘links’) if link[‘rel’]==’enclosure’] elif key == ‘license’: for link in dict.__getitem__(self, ‘links’): if link[‘rel’]==’license’ and ‘href’ in link: return link[‘href’] elif key == ‘updated’: # Temporarily help developers out by keeping the old # broken behavior that was reported in issue 310. # This fix was proposed in issue 328. if not dict.__contains__(self, ‘updated’) and \ dict.__contains__(self, ‘published’): warnings.warn(“To avoid breaking existing software while ” “fixing issue 310, a temporary mapping has been created ” “from `updated` to `published` if `updated` doesn’t ” “exist. This fallback will be removed in a future version ” “of feedparser.”, DeprecationWarning) return dict.__getitem__(self, ‘published’) return dict.__getitem__(self, ‘updated’) elif key == ‘updated_parsed’: if not dict.__contains__(self, ‘updated_parsed’) and \ dict.__contains__(self, ‘published_parsed’): warnings.warn(“To avoid breaking existing software while ” “fixing issue 310, a temporary mapping has been created ” “from `updated_parsed` to `published_parsed` if ” “`updated_parsed` doesn’t exist. This fallback will be ” “removed in a future version of feedparser.”, DeprecationWarning) return dict.__getitem__(self, ‘published_parsed’) return dict.__getitem__(self, ‘updated_parsed’) else: realkey = self.keymap.get(key, key) if isinstance(realkey, list): for k in realkey: if dict.__contains__(self, k): return dict.__getitem__(self, k) elif dict.__contains__(self, realkey): return dict.__getitem__(self, realkey) return dict.__getitem__(self, key) def __contains__(self, key): if key in (‘updated’, ‘updated_parsed’): # Temporarily help developers out by keeping the old # broken behavior that was reported in issue 310. # This fix was proposed in issue 328. return dict.__contains__(self, key) try: self.__getitem__(key) except KeyError: return False else: return True has_key = __contains__ def get(self, key, default=None): ”’ :return: A :class:`FeedParserDict`. ”’ try: return self.__getitem__(key) except KeyError: return default def __setitem__(self, key, value): key = self.keymap.get(key, key) if isinstance(key, list): key = key[0] return dict.__setitem__(self, key, value) def setdefault(self, key, value): if key not in self: self[key] = value return value return self[key] def __getattr__(self, key): # __getattribute__() is called first; this will be called # only if an attribute was not already found try: return self.__getitem__(key) except KeyError: raise AttributeError(“object has no attribute ‘%s'” % key) def __hash__(self): return id(self) _cp1252 = { 128: chr(8364), # euro sign 130: chr(8218), # single low-9 quotation mark 131: chr( 402), # latin small letter f with hook 132: chr(8222), # double low-9 quotation mark 133: chr(8230), # horizontal ellipsis 134: chr(8224), # dagger 135: chr(8225), # double dagger 136: chr( 710), # modifier letter circumflex accent 137: chr(8240), # per mille sign 138: chr( 352), # latin capital letter s with caron 139: chr(8249), # single left-pointing angle quotation mark 140: chr( 338), # latin capital ligature oe 142: chr( 381), # latin capital letter z with caron 145: chr(8216), # left single quotation mark 146: chr(8217), # right single quotation mark 147: chr(8220), # left double quotation mark 148: chr(8221), # right double quotation mark 149: chr(8226), # bullet 150: chr(8211), # en dash 151: chr(8212), # em dash 152: chr( 732), # small tilde 153: chr(8482), # trade mark sign 154: chr( 353), # latin small letter s with caron 155: chr(8250), # single right-pointing angle quotation mark 156: chr( 339), # latin small ligature oe 158: chr( 382), # latin small letter z with caron 159: chr( 376), # latin capital letter y with diaeresis } _urifixer = re.compile(‘^([A-Za-z][A-Za-z0-9+-.]*://)(/*)(.*?)’) def _urljoin(base, uri): uri = _urifixer.sub(r’\1\3′, uri) if not isinstance(uri, str): uri = uri.decode(‘utf-8’, ‘ignore’) try: uri = urllib.parse.urljoin(base, uri) except ValueError: uri = ” if not isinstance(uri, str): return uri.decode(‘utf-8’, ‘ignore’) return uri class _FeedParserMixin: namespaces = { ”: ”, ‘http://backend.userland.com/rss’: ”, ‘http://blogs.law.harvard.edu/tech/rss’: ”, ‘http://purl.org/rss/1.0/’: ”, ‘http://my.netscape.com/rdf/simple/0.9/’: ”, ‘http://example.com/newformat#’: ”, ‘http://example.com/necho’: ”, ‘http://purl.org/echo/’: ”, ‘uri/of/echo/namespace#’: ”, ‘http://purl.org/pie/’: ”, ‘http://purl.org/atom/ns#’: ”, ‘http://www.w3.org/2005/Atom’: ”, ‘http://purl.org/rss/1.0/modules/rss091#’: ”, ‘http://webns.net/mvcb/’: ‘admin’, ‘http://purl.org/rss/1.0/modules/aggregation/’: ‘ag’, ‘http://purl.org/rss/1.0/modules/annotate/’: ‘annotate’, ‘http://media.tangent.org/rss/1.0/’: ‘audio’, ‘http://backend.userland.com/blogChannelModule’: ‘blogChannel’, ‘http://web.resource.org/cc/’: ‘cc’, ‘http://backend.userland.com/creativeCommonsRssModule’: ‘creativeCommons’, ‘http://purl.org/rss/1.0/modules/company’: ‘co’, ‘http://purl.org/rss/1.0/modules/content/’: ‘content’, ‘http://my.theinfo.org/changed/1.0/rss/’: ‘cp’, ‘http://purl.org/dc/elements/1.1/’: ‘dc’, ‘http://purl.org/dc/terms/’: ‘dcterms’, ‘http://purl.org/rss/1.0/modules/email/’: ’email’, ‘http://purl.org/rss/1.0/modules/event/’: ‘ev’, ‘http://rssnamespace.org/feedburner/ext/1.0’: ‘feedburner’, ‘http://freshmeat.net/rss/fm/’: ‘fm’, ‘http://xmlns.com/foaf/0.1/’: ‘foaf’, ‘http://www.w3.org/2003/01/geo/wgs84_pos#’: ‘geo’, ‘http://www.georss.org/georss’: ‘georss’, ‘http://www.opengis.net/gml’: ‘gml’, ‘http://postneo.com/icbm/’: ‘icbm’, ‘http://purl.org/rss/1.0/modules/image/’: ‘image’, ‘http://www.itunes.com/DTDs/PodCast-1.0.dtd’: ‘itunes’, ‘http://example.com/DTDs/PodCast-1.0.dtd’: ‘itunes’, ‘http://purl.org/rss/1.0/modules/link/’: ‘l’, ‘http://search.yahoo.com/mrss’: ‘media’, # Version 1.1.2 of the Media RSS spec added the trailing slash on the namespace ‘http://search.yahoo.com/mrss/’: ‘media’, ‘http://madskills.com/public/xml/rss/module/pingback/’: ‘pingback’, ‘http://prismstandard.org/namespaces/1.2/basic/’: ‘prism’, ‘http://www.w3.org/1999/02/22-rdf-syntax-ns#’: ‘rdf’, ‘http://www.w3.org/2000/01/rdf-schema#’: ‘rdfs’, ‘http://purl.org/rss/1.0/modules/reference/’: ‘ref’, ‘http://purl.org/rss/1.0/modules/richequiv/’: ‘reqv’, ‘http://purl.org/rss/1.0/modules/search/’: ‘search’, ‘http://purl.org/rss/1.0/modules/slash/’: ‘slash’, ‘http://schemas.xmlsoap.org/soap/envelope/’: ‘soap’, ‘http://purl.org/rss/1.0/modules/servicestatus/’: ‘ss’, ‘http://hacks.benhammersley.com/rss/streaming/’: ‘str’, ‘http://purl.org/rss/1.0/modules/subscription/’: ‘sub’, ‘http://purl.org/rss/1.0/modules/syndication/’: ‘sy’, ‘http://schemas.pocketsoap.com/rss/myDescModule/’: ‘szf’, ‘http://purl.org/rss/1.0/modules/taxonomy/’: ‘taxo’, ‘http://purl.org/rss/1.0/modules/threading/’: ‘thr’, ‘http://purl.org/rss/1.0/modules/textinput/’: ‘ti’, ‘http://madskills.com/public/xml/rss/module/trackback/’: ‘trackback’, ‘http://wellformedweb.org/commentAPI/’: ‘wfw’, ‘http://purl.org/rss/1.0/modules/wiki/’: ‘wiki’, ‘http://www.w3.org/1999/xhtml’: ‘xhtml’, ‘http://www.w3.org/1999/xlink’: ‘xlink’, ‘http://www.w3.org/XML/1998/namespace’: ‘xml’, ‘http://podlove.org/simple-chapters’: ‘psc’, } _matchnamespaces = {} can_be_relative_uri = set([‘link’, ‘id’, ‘wfw_comment’, ‘wfw_commentrss’, ‘docs’, ‘url’, ‘href’, ‘comments’, ‘icon’, ‘logo’]) can_contain_relative_uris = set([‘content’, ‘title’, ‘summary’, ‘info’, ‘tagline’, ‘subtitle’, ‘copyright’, ‘rights’, ‘description’]) can_contain_dangerous_markup = set([‘content’, ‘title’, ‘summary’, ‘info’, ‘tagline’, ‘subtitle’, ‘copyright’, ‘rights’, ‘description’]) html_types = [‘text/html’, ‘application/xhtml+xml’] def __init__(self, baseuri=None, baselang=None, encoding=’utf-8′): if not self._matchnamespaces: for k, v in list(self.namespaces.items()): self._matchnamespaces[k.lower()] = v self.feeddata = FeedParserDict() # feed-level data self.encoding = encoding # character encoding self.entries = [] # list of entry-level data self.version = ” # feed type/version, see SUPPORTED_VERSIONS self.namespacesInUse = {} # dictionary of namespaces defined by the feed # the following are used internally to track state; # this is really out of control and should be refactored self.infeed = 0 self.inentry = 0 self.incontent = 0 self.intextinput = 0 self.inimage = 0 self.inauthor = 0 self.incontributor = 0 self.inpublisher = 0 self.insource = 0 # georss self.ingeometry = 0 self.sourcedata = FeedParserDict() self.contentparams = FeedParserDict() self._summaryKey = None self.namespacemap = {} self.elementstack = [] self.basestack = [] self.langstack = [] self.baseuri = baseuri or ” self.lang = baselang or None self.svgOK = 0 self.title_depth = -1 self.depth = 0 # psc_chapters_flag prevents multiple psc_chapters from being # captured in a single entry or item. The transition states are # None -> True -> False. psc_chapter elements will only be # captured while it is True. self.psc_chapters_flag = None if baselang: self.feeddata[‘language’] = baselang.replace(‘_’,’-‘) # A map of the following form: # { # object_that_value_is_set_on: { # property_name: depth_of_node_property_was_extracted_from, # other_property: depth_of_node_property_was_extracted_from, # }, # } self.property_depth_map = {} def _normalize_attributes(self, kv): k = kv[0].lower() v = k in (‘rel’, ‘type’) and kv[1].lower() or kv[1] # the sgml parser doesn’t handle entities in attributes, nor # does it pass the attribute values through as unicode, while # strict xml parsers do — account for this difference if isinstance(self, _LooseFeedParser): v = v.replace(‘&amp;’, ‘&’) if not isinstance(v, str): v = v.decode(‘utf-8’) return (k, v) def unknown_starttag(self, tag, attrs): # increment depth counter self.depth += 1 # normalize attrs attrs = list(map(self._normalize_attributes, attrs)) # track xml:base and xml:lang attrsD = dict(attrs) baseuri = attrsD.get(‘xml:base’, attrsD.get(‘base’)) or self.baseuri if not isinstance(baseuri, str): baseuri = baseuri.decode(self.encoding, ‘ignore’) # ensure that self.baseuri is always an absolute URI that # uses a whitelisted URI scheme (e.g. not `javscript:`) if self.baseuri: self.baseuri = _makeSafeAbsoluteURI(self.baseuri, baseuri) or self.baseuri else: self.baseuri = _urljoin(self.baseuri, baseuri) lang = attrsD.get(‘xml:lang’, attrsD.get(‘lang’)) if lang == ”: # xml:lang could be explicitly set to ”, we need to capture that lang = None elif lang is None: # if no xml:lang is specified, use parent lang lang = self.lang if lang: if tag in (‘feed’, ‘rss’, ‘rdf:RDF’): self.feeddata[‘language’] = lang.replace(‘_’,’-‘) self.lang = lang self.basestack.append(self.baseuri) self.langstack.append(lang) # track namespaces for prefix, uri in attrs: if prefix.startswith(‘xmlns:’): self.trackNamespace(prefix[6:], uri) elif prefix == ‘xmlns’: self.trackNamespace(None, uri) # track inline content if self.incontent and not self.contentparams.get(‘type’, ‘xml’).endswith(‘xml’): if tag in (‘xhtml:div’, ‘div’): return # typepad does this 10/2007 # element declared itself as escaped markup, but it isn’t really self.contentparams[‘type’] = ‘application/xhtml+xml’ if self.incontent and self.contentparams.get(‘type’) == ‘application/xhtml+xml’: if tag.find(‘:’) != -1: prefix, tag = tag.split(‘:’, 1) namespace = self.namespacesInUse.get(prefix, ”) if tag==’math’ and namespace==’http://www.w3.org/1998/Math/MathML’: attrs.append((‘xmlns’,namespace)) if tag==’svg’ and namespace==’http://www.w3.org/2000/svg’: attrs.append((‘xmlns’,namespace)) if tag == ‘svg’: self.svgOK += 1 return self.handle_data(‘<%s%s>’ % (tag, self.strattrs(attrs)), escape=0) # match namespaces if tag.find(‘:’) != -1: prefix, suffix = tag.split(‘:’, 1) else: prefix, suffix = ”, tag prefix = self.namespacemap.get(prefix, prefix) if prefix: prefix = prefix + ‘_’ # special hack for better tracking of empty textinput/image elements in illformed feeds if (not prefix) and tag not in (‘title’, ‘link’, ‘description’, ‘name’): self.intextinput = 0 if (not prefix) and tag not in (‘title’, ‘link’, ‘description’, ‘url’, ‘href’, ‘width’, ‘height’): self.inimage = 0 # call special handler (if defined) or default handler methodname = ‘_start_’ + prefix + suffix try: method = getattr(self, methodname) return method(attrsD) except AttributeError: # Since there’s no handler or something has gone wrong we explicitly add the element and its attributes unknown_tag = prefix + suffix if len(attrsD) == 0: # No attributes so merge it into the encosing dictionary return self.push(unknown_tag, 1) else: # Has attributes so create it in its own dictionary context = self._getContext() context[unknown_tag] = attrsD def unknown_endtag(self, tag): # match namespaces if tag.find(‘:’) != -1: prefix, suffix = tag.split(‘:’, 1) else: prefix, suffix = ”, tag prefix = self.namespacemap.get(prefix, prefix) if prefix: prefix = prefix + ‘_’ if suffix == ‘svg’ and self.svgOK: self.svgOK -= 1 # call special handler (if defined) or default handler methodname = ‘_end_’ + prefix + suffix try: if self.svgOK: raise AttributeError() method = getattr(self, methodname) method() except AttributeError: self.pop(prefix + suffix) # track inline content if self.incontent and not self.contentparams.get(‘type’, ‘xml’).endswith(‘xml’): # element declared itself as escaped markup, but it isn’t really if tag in (‘xhtml:div’, ‘div’): return # typepad does this 10/2007 self.contentparams[‘type’] = ‘application/xhtml+xml’ if self.incontent and self.contentparams.get(‘type’) == ‘application/xhtml+xml’: tag = tag.split(‘:’)[-1] self.handle_data(‘</%s>’ % tag, escape=0) # track xml:base and xml:lang going out of scope if self.basestack: self.basestack.pop() if self.basestack and self.basestack[-1]: self.baseuri = self.basestack[-1] if self.langstack: self.langstack.pop() if self.langstack: # and (self.langstack[-1] is not None): self.lang = self.langstack[-1] self.depth -= 1 def handle_charref(self, ref): # called for each character reference, e.g. for ‘ ’, ref will be ‘160’ if not self.elementstack: return ref = ref.lower() if ref in (’34’, ’38’, ’39’, ’60’, ’62’, ‘x22’, ‘x26’, ‘x27’, ‘x3c’, ‘x3e’): text = ‘&#%s;’ % ref else: if ref[0] == ‘x’: c = int(ref[1:], 16) else: c = int(ref) text = chr(c).encode(‘utf-8’) self.elementstack[-1][2].append(text) def handle_entityref(self, ref): # called for each entity reference, e.g. for ‘&copy;’, ref will be ‘copy’ if not self.elementstack: return if ref in (‘lt’, ‘gt’, ‘quot’, ‘amp’, ‘apos’): text = ‘&%s;’ % ref elif ref in self.entities: text = self.entities[ref] if text.startswith(‘&#’) and text.endswith(‘;’): return self.handle_entityref(text) else: try: name2codepoint[ref] except KeyError: text = ‘&%s;’ % ref else: text = chr(name2codepoint[ref]).encode(‘utf-8’) self.elementstack[-1][2].append(text) def handle_data(self, text, escape=1): # called for each block of plain text, i.e. outside of any tag and # not containing any character or entity references if not self.elementstack: return if escape and self.contentparams.get(‘type’) == ‘application/xhtml+xml’: text = _xmlescape(text) self.elementstack[-1][2].append(text) def handle_comment(self, text): # called for each comment, e.g. <!– insert message here –> pass def handle_pi(self, text): # called for each processing instruction, e.g. <?instruction> pass def handle_decl(self, text): pass def parse_declaration(self, i): # override internal declaration handler to handle CDATA blocks if self.rawdata[i:i+9] == ‘<![CDATA[‘: k = self.rawdata.find(‘]]>’, i) if k == -1: # CDATA block began but didn’t finish k = len(self.rawdata) return k self.handle_data(_xmlescape(self.rawdata[i+9:k]), 0) return k+3 else: k = self.rawdata.find(‘>’, i) if k >= 0: return k+1 else: # We have an incomplete CDATA block. return k def mapContentType(self, contentType): contentType = contentType.lower() if contentType == ‘text’ or contentType == ‘plain’: contentType = ‘text/plain’ elif contentType == ‘html’: contentType = ‘text/html’ elif contentType == ‘xhtml’: contentType = ‘application/xhtml+xml’ return contentType def trackNamespace(self, prefix, uri): loweruri = uri.lower() if not self.version: if (prefix, loweruri) == (None, ‘http://my.netscape.com/rdf/simple/0.9/’): self.version = ‘rss090’ elif loweruri == ‘http://purl.org/rss/1.0/’: self.version = ‘rss10’ elif loweruri == ‘http://www.w3.org/2005/atom’: self.version = ‘atom10’ if loweruri.find(‘backend.userland.com/rss’) != -1: # match any backend.userland.com namespace uri = ‘http://backend.userland.com/rss’ loweruri = uri if loweruri in self._matchnamespaces: self.namespacemap[prefix] = self._matchnamespaces[loweruri] self.namespacesInUse[self._matchnamespaces[loweruri]] = uri else: self.namespacesInUse[prefix or ”] = uri def resolveURI(self, uri): return _urljoin(self.baseuri or ”, uri) def decodeEntities(self, element, data): return data def strattrs(self, attrs): return ”.join([‘ %s=”%s”‘ % (t[0],_xmlescape(t[1],{‘”‘:’&quot;’})) for t in attrs]) def push(self, element, expectingText): self.elementstack.append([element, expectingText, []]) def pop(self, element, stripWhitespace=1): if not self.elementstack: return if self.elementstack[-1][0] != element: return element, expectingText, pieces = self.elementstack.pop() if self.version == ‘atom10’ and self.contentparams.get(‘type’, ‘text’) == ‘application/xhtml+xml’: # remove enclosing child element, but only if it is a <div> and # only if all the remaining content is nested underneath it. # This means that the divs would be retained in the following: # <div>foo</div><div>bar</div> while pieces and len(pieces)>1 and not pieces[-1].strip(): del pieces[-1] while pieces and len(pieces)>1 and not pieces[0].strip(): del pieces[0] if pieces and (pieces[0] == ‘<div>’ or pieces[0].startswith(‘<div ‘)) and pieces[-1]=='</div>’: depth = 0 for piece in pieces[:-1]: if piece.startswith(‘</’): depth -= 1 if depth == 0: break elif piece.startswith(‘<‘) and not piece.endswith(‘/>’): depth += 1 else: pieces = pieces[1:-1] # Ensure each piece is a str for Python 3 for (i, v) in enumerate(pieces): if not isinstance(v, str): pieces[i] = v.decode(‘utf-8’) output = ”.join(pieces) if stripWhitespace: output = output.strip() if not expectingText: return output # decode base64 content if base64 and self.contentparams.get(‘base64’, 0): try: output = _base64decode(output) except binascii.Error: pass except binascii.Incomplete: pass except TypeError: # In Python 3, base64 takes and outputs bytes, not str # This may not be the most correct way to accomplish this output = _base64decode(output.encode(‘utf-8’)).decode(‘utf-8’) # resolve relative URIs if (element in self.can_be_relative_uri) and output: # do not resolve guid elements with isPermalink=”false” if not element == ‘id’ or self.guidislink: output = self.resolveURI(output) # decode entities within embedded markup if not self.contentparams.get(‘base64’, 0): output = self.decodeEntities(element, output) # some feed formats require consumers to guess # whether the content is html or plain text if not self.version.startswith(‘atom’) and self.contentparams.get(‘type’) == ‘text/plain’: if self.lookslikehtml(output): self.contentparams[‘type’] = ‘text/html’ # remove temporary cruft from contentparams try: del self.contentparams[‘mode’] except KeyError: pass try: del self.contentparams[‘base64’] except KeyError: pass is_htmlish = self.mapContentType(self.contentparams.get(‘type’, ‘text/html’)) in self.html_types # resolve relative URIs within embedded markup if is_htmlish and RESOLVE_RELATIVE_URIS: if element in self.can_contain_relative_uris: output = _resolveRelativeURIs(output, self.baseuri, self.encoding, self.contentparams.get(‘type’, ‘text/html’)) # sanitize embedded markup if is_htmlish and SANITIZE_HTML: if element in self.can_contain_dangerous_markup: output = _sanitizeHTML(output, self.encoding, self.contentparams.get(‘type’, ‘text/html’)) if self.encoding and not isinstance(output, str): output = output.decode(self.encoding, ‘ignore’) # address common error where people take data that is already # utf-8, presume that it is iso-8859-1, and re-encode it. if self.encoding in (‘utf-8’, ‘utf-8_INVALID_PYTHON_3’) and isinstance(output, str): try: output = output.encode(‘iso-8859-1’).decode(‘utf-8’) except (UnicodeEncodeError, UnicodeDecodeError): pass # map win-1252 extensions to the proper code points if isinstance(output, str): output = output.translate(_cp1252) # categories/tags/keywords/whatever are handled in _end_category or _end_tags or _end_itunes_keywords if element in (‘category’, ‘tags’, ‘itunes_keywords’): return output if element == ‘title’ and -1 < self.title_depth <= self.depth: return output # store output in appropriate place(s) if self.inentry and not self.insource: if element == ‘content’: self.entries[-1].setdefault(element, []) contentparams = copy.deepcopy(self.contentparams) contentparams[‘value’] = output self.entries[-1][element].append(contentparams) elif element == ‘link’: if not self.inimage: # query variables in urls in link elements are improperly # converted from `?a=1&b=2` to `?a=1&b;=2` as if they’re # unhandled character references. fix this special case. output = output.replace(‘&amp;’, ‘&’) output = re.sub(“&([A-Za-z0-9_]+);”, “&\g<1>”, output) self.entries[-1][element] = output if output: self.entries[-1][‘links’][-1][‘href’] = output else: if element == ‘description’: element = ‘summary’ old_value_depth = self.property_depth_map.setdefault(self.entries[-1], {}).get(element) if old_value_depth is None or self.depth <= old_value_depth: self.property_depth_map[self.entries[-1]][element] = self.depth self.entries[-1][element] = output if self.incontent: contentparams = copy.deepcopy(self.contentparams) contentparams[‘value’] = output self.entries[-1][element + ‘_detail’] = contentparams elif (self.infeed or self.insource):# and (not self.intextinput) and (not self.inimage): context = self._getContext() if element == ‘description’: element = ‘subtitle’ context[element] = output if element == ‘link’: # fix query variables; see above for the explanation output = re.sub(“&([A-Za-z0-9_]+);”, “&\g<1>”, output) context[element] = output context[‘links’][-1][‘href’] = output elif self.incontent: contentparams = copy.deepcopy(self.contentparams) contentparams[‘value’] = output context[element + ‘_detail’] = contentparams return output def pushContent(self, tag, attrsD, defaultContentType, expectingText): self.incontent += 1 if self.lang: self.lang=self.lang.replace(‘_’,’-‘) self.contentparams = FeedParserDict({ ‘type’: self.mapContentType(attrsD.get(‘type’, defaultContentType)), ‘language’: self.lang, ‘base’: self.baseuri}) self.contentparams[‘base64′] = self._isBase64(attrsD, self.contentparams) self.push(tag, expectingText) def popContent(self, tag): value = self.pop(tag) self.incontent -= 1 self.contentparams.clear() return value # a number of elements in a number of RSS variants are nominally plain # text, but this is routinely ignored. This is an attempt to detect # the most common cases. As false positives often result in silent # data loss, this function errs on the conservative side. @staticmethod def lookslikehtml(s): # must have a close tag or an entity reference to qualify if not (re.search(r'</(\w+)>’,s) or re.search(“&#?\w+;”,s)): return # all tags must be in a restricted subset of valid HTML tags if [t for t in re.findall(r'</?(\w+)’,s) if t.lower() not in _HTMLSanitizer.acceptable_elements]: return # all entities must have been defined as valid HTML entities if [e for e in re.findall(r’&(\w+);’, s) if e not in list(entitydefs.keys())]: return return 1 def _mapToStandardPrefix(self, name): colonpos = name.find(‘:’) if colonpos != -1: prefix = name[:colonpos] suffix = name[colonpos+1:] prefix = self.namespacemap.get(prefix, prefix) name = prefix + ‘:’ + suffix return name def _getAttribute(self, attrsD, name): return attrsD.get(self._mapToStandardPrefix(name)) def _isBase64(self, attrsD, contentparams): if attrsD.get(‘mode’, ”) == ‘base64’: return 1 if self.contentparams[‘type’].startswith(‘text/’): return 0 if self.contentparams[‘type’].endswith(‘+xml’): return 0 if self.contentparams[‘type’].endswith(‘/xml’): return 0 return 1 def _itsAnHrefDamnIt(self, attrsD): href = attrsD.get(‘url’, attrsD.get(‘uri’, attrsD.get(‘href’, None))) if href: try: del attrsD[‘url’] except KeyError: pass try: del attrsD[‘uri’] except KeyError: pass attrsD[‘href’] = href return attrsD def _save(self, key, value, overwrite=False): context = self._getContext() if overwrite: context[key] = value else: context.setdefault(key, value) def _start_rss(self, attrsD): versionmap = {‘0.91’: ‘rss091u’, ‘0.92’: ‘rss092’, ‘0.93’: ‘rss093’, ‘0.94’: ‘rss094’} #If we’re here then this is an RSS feed. #If we don’t have a version or have a version that starts with something #other than RSS then there’s been a mistake. Correct it. if not self.version or not self.version.startswith(‘rss’): attr_version = attrsD.get(‘version’, ”) version = versionmap.get(attr_version) if version: self.version = version elif attr_version.startswith(‘2.’): self.version = ‘rss20’ else: self.version = ‘rss’ def _start_channel(self, attrsD): self.infeed = 1 self._cdf_common(attrsD) def _cdf_common(self, attrsD): if ‘lastmod’ in attrsD: self._start_modified({}) self.elementstack[-1][-1] = attrsD[‘lastmod’] self._end_modified() if ‘href’ in attrsD: self._start_link({}) self.elementstack[-1][-1] = attrsD[‘href’] self._end_link() def _start_feed(self, attrsD): self.infeed = 1 versionmap = {‘0.1’: ‘atom01’, ‘0.2’: ‘atom02’, ‘0.3’: ‘atom03’} if not self.version: attr_version = attrsD.get(‘version’) version = versionmap.get(attr_version) if version: self.version = version else: self.version = ‘atom’ def _end_channel(self): self.infeed = 0 _end_feed = _end_channel def _start_image(self, attrsD): context = self._getContext() if not self.inentry: context.setdefault(‘image’, FeedParserDict()) self.inimage = 1 self.title_depth = -1 self.push(‘image’, 0) def _end_image(self): self.pop(‘image’) self.inimage = 0 def _start_textinput(self, attrsD): context = self._getContext() context.setdefault(‘textinput’, FeedParserDict()) self.intextinput = 1 self.title_depth = -1 self.push(‘textinput’, 0) _start_textInput = _start_textinput def _end_textinput(self): self.pop(‘textinput’) self.intextinput = 0 _end_textInput = _end_textinput def _start_author(self, attrsD): self.inauthor = 1 self.push(‘author’, 1) # Append a new FeedParserDict when expecting an author context = self._getContext() context.setdefault(‘authors’, []) context[‘authors’].append(FeedParserDict()) _start_managingeditor = _start_author _start_dc_author = _start_author _start_dc_creator = _start_author _start_itunes_author = _start_author def _end_author(self): self.pop(‘author’) self.inauthor = 0 self._sync_author_detail() _end_managingeditor = _end_author _end_dc_author = _end_author _end_dc_creator = _end_author _end_itunes_author = _end_author def _start_itunes_owner(self, attrsD): self.inpublisher = 1 self.push(‘publisher’, 0) def _end_itunes_owner(self): self.pop(‘publisher’) self.inpublisher = 0 self._sync_author_detail(‘publisher’) def _start_contributor(self, attrsD): self.incontributor = 1 context = self._getContext() context.setdefault(‘contributors’, []) context[‘contributors’].append(FeedParserDict()) self.push(‘contributor’, 0) def _end_contributor(self): self.pop(‘contributor’) self.incontributor = 0 def _start_dc_contributor(self, attrsD): self.incontributor = 1 context = self._getContext() context.setdefault(‘contributors’, []) context[‘contributors’].append(FeedParserDict()) self.push(‘name’, 0) def _end_dc_contributor(self): self._end_name() self.incontributor = 0 def _start_name(self, attrsD): self.push(‘name’, 0) _start_itunes_name = _start_name def _end_name(self): value = self.pop(‘name’) if self.inpublisher: self._save_author(‘name’, value, ‘publisher’) elif self.inauthor: self._save_author(‘name’, value) elif self.incontributor: self._save_contributor(‘name’, value) elif self.intextinput: context = self._getContext() context[‘name’] = value _end_itunes_name = _end_name def _start_width(self, attrsD): self.push(‘width’, 0) def _end_width(self): value = self.pop(‘width’) try: value = int(value) except ValueError: value = 0 if self.inimage: context = self._getContext() context[‘width’] = value def _start_height(self, attrsD): self.push(‘height’, 0) def _end_height(self): value = self.pop(‘height’) try: value = int(value) except ValueError: value = 0 if self.inimage: context = self._getContext() context[‘height’] = value def _start_url(self, attrsD): self.push(‘href’, 1) _start_homepage = _start_url _start_uri = _start_url def _end_url(self): value = self.pop(‘href’) if self.inauthor: self._save_author(‘href’, value) elif self.incontributor: self._save_contributor(‘href’, value) _end_homepage = _end_url _end_uri = _end_url def _start_email(self, attrsD): self.push(’email’, 0) _start_itunes_email = _start_email def _end_email(self): value = self.pop(’email’) if self.inpublisher: self._save_author(’email’, value, ‘publisher’) elif self.inauthor: self._save_author(’email’, value) elif self.incontributor: self._save_contributor(’email’, value) _end_itunes_email = _end_email def _getContext(self): if self.insource: context = self.sourcedata elif self.inimage and ‘image’ in self.feeddata: context = self.feeddata[‘image’] elif self.intextinput: context = self.feeddata[‘textinput’] elif self.inentry: context = self.entries[-1] else: context = self.feeddata return context def _save_author(self, key, value, prefix=’author’): context = self._getContext() context.setdefault(prefix + ‘_detail’, FeedParserDict()) context[prefix + ‘_detail’][key] = value self._sync_author_detail() context.setdefault(‘authors’, [FeedParserDict()]) context[‘authors’][-1][key] = value def _save_contributor(self, key, value): context = self._getContext() context.setdefault(‘contributors’, [FeedParserDict()]) context[‘contributors’][-1][key] = value def _sync_author_detail(self, key=’author’): context = self._getContext() detail = context.get(‘%ss’ % key, [FeedParserDict()])[-1] if detail: name = detail.get(‘name’) email = detail.get(’email’) if name and email: context[key] = ‘%s (%s)’ % (name, email) elif name: context[key] = name elif email: context[key] = email else: author, email = context.get(key), None if not author: return emailmatch = re.search(r”'(([a-zA-Z0-9\_\-\.\+]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?))(\?subject=\S+)?”’, author) if emailmatch: email = emailmatch.group(0) # probably a better way to do the following, but it passes all the tests author = author.replace(email, ”) author = author.replace(‘()’, ”) author = author.replace(‘<>’, ”) author = author.replace(‘&lt;&gt;’, ”) author = author.strip() if author and (author[0] == ‘(‘): author = author[1:] if author and (author[-1] == ‘)’): author = author[:-1] author = author.strip() if author or email: context.setdefault(‘%s_detail’ % key, detail) if author: detail[‘name’] = author if email: detail[’email’] = email def _start_subtitle(self, attrsD): self.pushContent(‘subtitle’, attrsD, ‘text/plain’, 1) _start_tagline = _start_subtitle _start_itunes_subtitle = _start_subtitle def _end_subtitle(self): self.popContent(‘subtitle’) _end_tagline = _end_subtitle _end_itunes_subtitle = _end_subtitle def _start_rights(self, attrsD): self.pushContent(‘rights’, attrsD, ‘text/plain’, 1) _start_dc_rights = _start_rights _start_copyright = _start_rights def _end_rights(self): self.popContent(‘rights’) _end_dc_rights = _end_rights _end_copyright = _end_rights def _start_item(self, attrsD): self.entries.append(FeedParserDict()) self.push(‘item’, 0) self.inentry = 1 self.guidislink = 0 self.title_depth = -1 self.psc_chapters_flag = None id = self._getAttribute(attrsD, ‘rdf:about’) if id: context = self._getContext() context[‘id’] = id self._cdf_common(attrsD) _start_entry = _start_item def _end_item(self): self.pop(‘item’) self.inentry = 0 _end_entry = _end_item def _start_dc_language(self, attrsD): self.push(‘language’, 1) _start_language = _start_dc_language def _end_dc_language(self): self.lang = self.pop(‘language’) _end_language = _end_dc_language def _start_dc_publisher(self, attrsD): self.push(‘publisher’, 1) _start_webmaster = _start_dc_publisher def _end_dc_publisher(self): self.pop(‘publisher’) self._sync_author_detail(‘publisher’) _end_webmaster = _end_dc_publisher def _start_dcterms_valid(self, attrsD): self.push(‘validity’, 1) def _end_dcterms_valid(self): for validity_detail in self.pop(‘validity’).split(‘;’): if ‘=’ in validity_detail: key, value = validity_detail.split(‘=’, 1) if key == ‘start’: self._save(‘validity_start’, value, overwrite=True) self._save(‘validity_start_parsed’, _parse_date(value), overwrite=True) elif key == ‘end’: self._save(‘validity_end’, value, overwrite=True) self._save(‘validity_end_parsed’, _parse_date(value), overwrite=True) def _start_published(self, attrsD): self.push(‘published’, 1) _start_dcterms_issued = _start_published _start_issued = _start_published _start_pubdate = _start_published def _end_published(self): value = self.pop(‘published’) self._save(‘published_parsed’, _parse_date(value), overwrite=True) _end_dcterms_issued = _end_published _end_issued = _end_published _end_pubdate = _end_published def _start_updated(self, attrsD): self.push(‘updated’, 1) _start_modified = _start_updated _start_dcterms_modified = _start_updated _start_dc_date = _start_updated _start_lastbuilddate = _start_updated def _end_updated(self): value = self.pop(‘updated’) parsed_value = _parse_date(value) self._save(‘updated_parsed’, parsed_value, overwrite=True) _end_modified = _end_updated _end_dcterms_modified = _end_updated _end_dc_date = _end_updated _end_lastbuilddate = _end_updated def _start_created(self, attrsD): self.push(‘created’, 1) _start_dcterms_created = _start_created def _end_created(self): value = self.pop(‘created’) self._save(‘created_parsed’, _parse_date(value), overwrite=True) _end_dcterms_created = _end_created def _start_expirationdate(self, attrsD): self.push(‘expired’, 1) def _end_expirationdate(self): self._save(‘expired_parsed’, _parse_date(self.pop(‘expired’)), overwrite=True) # geospatial location, or “where”, from georss.org def _start_georssgeom(self, attrsD): self.push(‘geometry’, 0) context = self._getContext() context[‘where’] = FeedParserDict() _start_georss_point = _start_georssgeom _start_georss_line = _start_georssgeom _start_georss_polygon = _start_georssgeom _start_georss_box = _start_georssgeom def _save_where(self, geometry): context = self._getContext() context[‘where’].update(geometry) def _end_georss_point(self): geometry = _parse_georss_point(self.pop(‘geometry’)) if geometry: self._save_where(geometry) def _end_georss_line(self): geometry = _parse_georss_line(self.pop(‘geometry’)) if geometry: self._save_where(geometry) def _end_georss_polygon(self): this = self.pop(‘geometry’) geometry = _parse_georss_polygon(this) if geometry: self._save_where(geometry) def _end_georss_box(self): geometry = _parse_georss_box(self.pop(‘geometry’)) if geometry: self._save_where(geometry) def _start_where(self, attrsD): self.push(‘where’, 0) context = self._getContext() context[‘where’] = FeedParserDict() _start_georss_where = _start_where def _parse_srs_attrs(self, attrsD): srsName = attrsD.get(‘srsname’) try: srsDimension = int(attrsD.get(‘srsdimension’, ‘2’)) except ValueError: srsDimension = 2 context = self._getContext() context[‘where’][‘srsName’] = srsName context[‘where’][‘srsDimension’] = srsDimension def _start_gml_point(self, attrsD): self._parse_srs_attrs(attrsD) self.ingeometry = 1 self.push(‘geometry’, 0) def _start_gml_linestring(self, attrsD): self._parse_srs_attrs(attrsD) self.ingeometry = ‘linestring’ self.push(‘geometry’, 0) def _start_gml_polygon(self, attrsD): self._parse_srs_attrs(attrsD) self.push(‘geometry’, 0) def _start_gml_exterior(self, attrsD): self.push(‘geometry’, 0) def _start_gml_linearring(self, attrsD): self.ingeometry = ‘polygon’ self.push(‘geometry’, 0) def _start_gml_pos(self, attrsD): self.push(‘pos’, 0) def _end_gml_pos(self): this = self.pop(‘pos’) context = self._getContext() srsName = context[‘where’].get(‘srsName’) srsDimension = context[‘where’].get(‘srsDimension’, 2) swap = True if srsName and “EPSG” in srsName: epsg = int(srsName.split(“:”)[-1]) swap = bool(epsg in _geogCS) geometry = _parse_georss_point(this, swap=swap, dims=srsDimension) if geometry: self._save_where(geometry) def _start_gml_poslist(self, attrsD): self.push(‘pos’, 0) def _end_gml_poslist(self): this = self.pop(‘pos’) context = self._getContext() srsName = context[‘where’].get(‘srsName’) srsDimension = context[‘where’].get(‘srsDimension’, 2) swap = True if srsName and “EPSG” in srsName: epsg = int(srsName.split(“:”)[-1]) swap = bool(epsg in _geogCS) geometry = _parse_poslist( this, self.ingeometry, swap=swap, dims=srsDimension) if geometry: self._save_where(geometry) def _end_geom(self): self.ingeometry = 0 self.pop(‘geometry’) _end_gml_point = _end_geom _end_gml_linestring = _end_geom _end_gml_linearring = _end_geom _end_gml_exterior = _end_geom _end_gml_polygon = _end_geom def _end_where(self): self.pop(‘where’) _end_georss_where = _end_where # end geospatial def _start_cc_license(self, attrsD): context = self._getContext() value = self._getAttribute(attrsD, ‘rdf:resource’) attrsD = FeedParserDict() attrsD[‘rel’] = ‘license’ if value: attrsD[‘href’]=value context.setdefault(‘links’, []).append(attrsD) def _start_creativecommons_license(self, attrsD): self.push(‘license’, 1) _start_creativeCommons_license = _start_creativecommons_license def _end_creativecommons_license(self): value = self.pop(‘license’) context = self._getContext() attrsD = FeedParserDict() attrsD[‘rel’] = ‘license’ if value: attrsD[‘href’] = value context.setdefault(‘links’, []).append(attrsD) del context[‘license’] _end_creativeCommons_license = _end_creativecommons_license def _addTag(self, term, scheme, label): context = self._getContext() tags = context.setdefault(‘tags’, []) if (not term) and (not scheme) and (not label): return value = FeedParserDict(term=term, scheme=scheme, label=label) if value not in tags: tags.append(value) def _start_tags(self, attrsD): # This is a completely-made up element. Its semantics are determined # only by a single feed that precipitated bug report 392 on Google Code. # In short, this is junk code. self.push(‘tags’, 1) def _end_tags(self): for term in self.pop(‘tags’).split(‘,’): self._addTag(term.strip(), None, None) def _start_category(self, attrsD): term = attrsD.get(‘term’) scheme = attrsD.get(‘scheme’, attrsD.get(‘domain’)) label = attrsD.get(‘label’) self._addTag(term, scheme, label) self.push(‘category’, 1) _start_dc_subject = _start_category _start_keywords = _start_category def _start_media_category(self, attrsD): attrsD.setdefault(‘scheme’, ‘http://search.yahoo.com/mrss/category_schema’) self._start_category(attrsD) def _end_itunes_keywords(self): for term in self.pop(‘itunes_keywords’).split(‘,’): if term.strip(): self._addTag(term.strip(), ‘http://www.itunes.com/’, None) def _end_media_keywords(self): for term in self.pop(‘media_keywords’).split(‘,’): if term.strip(): self._addTag(term.strip(), None, None) def _start_itunes_category(self, attrsD): self._addTag(attrsD.get(‘text’), ‘http://www.itunes.com/’, None) self.push(‘category’, 1) def _end_category(self): value = self.pop(‘category’) if not value: return context = self._getContext() tags = context[‘tags’] if value and len(tags) and not tags[-1][‘term’]: tags[-1][‘term’] = value else: self._addTag(value, None, None) _end_dc_subject = _end_category _end_keywords = _end_category _end_itunes_category = _end_category _end_media_category = _end_category def _start_cloud(self, attrsD): self._getContext()[‘cloud’] = FeedParserDict(attrsD) def _start_link(self, attrsD): attrsD.setdefault(‘rel’, ‘alternate’) if attrsD[‘rel’] == ‘self’: attrsD.setdefault(‘type’, ‘application/atom+xml’) else: attrsD.setdefault(‘type’, ‘text/html’) context = self._getContext() attrsD = self._itsAnHrefDamnIt(attrsD) if ‘href’ in attrsD: attrsD[‘href’] = self.resolveURI(attrsD[‘href’]) expectingText = self.infeed or self.inentry or self.insource context.setdefault(‘links’, []) if not (self.inentry and self.inimage): context[‘links’].append(FeedParserDict(attrsD)) if ‘href’ in attrsD: expectingText = 0 if (attrsD.get(‘rel’) == ‘alternate’) and (self.mapContentType(attrsD.get(‘type’)) in self.html_types): context[‘link’] = attrsD[‘href’] else: self.push(‘link’, expectingText) def _end_link(self): value = self.pop(‘link’) def _start_guid(self, attrsD): self.guidislink = (attrsD.get(‘ispermalink’, ‘true’) == ‘true’) self.push(‘id’, 1) _start_id = _start_guid def _end_guid(self): value = self.pop(‘id’) self._save(‘guidislink’, self.guidislink and ‘link’ not in self._getContext()) if self.guidislink: # guid acts as link, but only if ‘ispermalink’ is not present or is ‘true’, # and only if the item doesn’t already have a link element self._save(‘link’, value) _end_id = _end_guid def _start_title(self, attrsD): if self.svgOK: return self.unknown_starttag(‘title’, list(attrsD.items())) self.pushContent(‘title’, attrsD, ‘text/plain’, self.infeed or self.inentry or self.insource) _start_dc_title = _start_title _start_media_title = _start_title def _end_title(self): if self.svgOK: return value = self.popContent(‘title’) if not value: return self.title_depth = self.depth _end_dc_title = _end_title def _end_media_title(self): title_depth = self.title_depth self._end_title() self.title_depth = title_depth def _start_description(self, attrsD): context = self._getContext() if ‘summary’ in context: self._summaryKey = ‘content’ self._start_content(attrsD) else: self.pushContent(‘description’, attrsD, ‘text/html’, self.infeed or self.inentry or self.insource) _start_dc_description = _start_description _start_media_description = _start_description def _start_abstract(self, attrsD): self.pushContent(‘description’, attrsD, ‘text/plain’, self.infeed or self.inentry or self.insource) def _end_description(self): if self._summaryKey == ‘content’: self._end_content() else: value = self.popContent(‘description’) self._summaryKey = None _end_abstract = _end_description _end_dc_description = _end_description _end_media_description = _end_description def _start_info(self, attrsD): self.pushContent(‘info’, attrsD, ‘text/plain’, 1) _start_feedburner_browserfriendly = _start_info def _end_info(self): self.popContent(‘info’) _end_feedburner_browserfriendly = _end_info def _start_generator(self, attrsD): if attrsD: attrsD = self._itsAnHrefDamnIt(attrsD) if ‘href’ in attrsD: attrsD[‘href’] = self.resolveURI(attrsD[‘href’]) self._getContext()[‘generator_detail’] = FeedParserDict(attrsD) self.push(‘generator’, 1) def _end_generator(self): value = self.pop(‘generator’) context = self._getContext() if ‘generator_detail’ in context: context[‘generator_detail’][‘name’] = value def _start_admin_generatoragent(self, attrsD): self.push(‘generator’, 1) value = self._getAttribute(attrsD, ‘rdf:resource’) if value: self.elementstack[-1][2].append(value) self.pop(‘generator’) self._getContext()[‘generator_detail’] = FeedParserDict({‘href’: value}) def _start_admin_errorreportsto(self, attrsD): self.push(‘errorreportsto’, 1) value = self._getAttribute(attrsD, ‘rdf:resource’) if value: self.elementstack[-1][2].append(value) self.pop(‘errorreportsto’) def _start_summary(self, attrsD): context = self._getContext() if ‘summary’ in context: self._summaryKey = ‘content’ self._start_content(attrsD) else: self._summaryKey = ‘summary’ self.pushContent(self._summaryKey, attrsD, ‘text/plain’, 1) _start_itunes_summary = _start_summary def _end_summary(self): if self._summaryKey == ‘content’: self._end_content() else: self.popContent(self._summaryKey or ‘summary’) self._summaryKey = None _end_itunes_summary = _end_summary def _start_enclosure(self, attrsD): attrsD = self._itsAnHrefDamnIt(attrsD) context = self._getContext() attrsD[‘rel’] = ‘enclosure’ context.setdefault(‘links’, []).append(FeedParserDict(attrsD)) def _start_source(self, attrsD): if ‘url’ in attrsD: # This means that we’re processing a source element from an RSS 2.0 feed self.sourcedata[‘href’] = attrsD[‘url’] self.push(‘source’, 1) self.insource = 1 self.title_depth = -1 def _end_source(self): self.insource = 0 value = self.pop(‘source’) if value: self.sourcedata[‘title’] = value self._getContext()[‘source’] = copy.deepcopy(self.sourcedata) self.sourcedata.clear() def _start_content(self, attrsD): self.pushContent(‘content’, attrsD, ‘text/plain’, 1) src = attrsD.get(‘src’) if src: self.contentparams[‘src’] = src self.push(‘content’, 1) def _start_body(self, attrsD): self.pushContent(‘content’, attrsD, ‘application/xhtml+xml’, 1) _start_xhtml_body = _start_body def _start_content_encoded(self, attrsD): self.pushContent(‘content’, attrsD, ‘text/html’, 1) _start_fullitem = _start_content_encoded def _end_content(self): copyToSummary = self.mapContentType(self.contentparams.get(‘type’)) in ([‘text/plain’] + self.html_types) value = self.popContent(‘content’) if copyToSummary: self._save(‘summary’, value) _end_body = _end_content _end_xhtml_body = _end_content _end_content_encoded = _end_content _end_fullitem = _end_content def _start_itunes_image(self, attrsD): self.push(‘itunes_image’, 0) if attrsD.get(‘href’): self._getContext()[‘image’] = FeedParserDict({‘href’: attrsD.get(‘href’)}) elif attrsD.get(‘url’): self._getContext()[‘image’] = FeedParserDict({‘href’: attrsD.get(‘url’)}) _start_itunes_link = _start_itunes_image def _end_itunes_block(self): value = self.pop(‘itunes_block’, 0) self._getContext()[‘itunes_block’] = (value == ‘yes’) and 1 or 0 def _end_itunes_explicit(self): value = self.pop(‘itunes_explicit’, 0) # Convert ‘yes’ -> True, ‘clean’ to False, and any other value to None # False and None both evaluate as False, so the difference can be ignored # by applications that only need to know if the content is explicit. self._getContext()[‘itunes_explicit’] = (None, False, True)[(value == ‘yes’ and 2) or value == ‘clean’ or 0] def _start_media_group(self, attrsD): # don’t do anything, but don’t break the enclosed tags either pass def _start_media_rating(self, attrsD): context = self._getContext() context.setdefault(‘media_rating’, attrsD) self.push(‘rating’, 1) def _end_media_rating(self): rating = self.pop(‘rating’) if rating is not None and rating.strip(): context = self._getContext() context[‘media_rating’][‘content’] = rating def _start_media_credit(self, attrsD): context = self._getContext() context.setdefault(‘media_credit’, []) context[‘media_credit’].append(attrsD) self.push(‘credit’, 1) def _end_media_credit(self): credit = self.pop(‘credit’) if credit != None and len(credit.strip()) != 0: context = self._getContext() context[‘media_credit’][-1][‘content’] = credit def _start_media_restriction(self, attrsD): context = self._getContext() context.setdefault(‘media_restriction’, attrsD) self.push(‘restriction’, 1) def _end_media_restriction(self): restriction = self.pop(‘restriction’) if restriction != None and len(restriction.strip()) != 0: context = self._getContext() context[‘media_restriction’][‘content’] = [cc.strip().lower() for cc in restriction.split(‘ ‘)] def _start_media_license(self, attrsD): context = self._getContext() context.setdefault(‘media_license’, attrsD) self.push(‘license’, 1) def _end_media_license(self): license = self.pop(‘license’) if license != None and len(license.strip()) != 0: context = self._getContext() context[‘media_license’][‘content’] = license def _start_media_content(self, attrsD): context = self._getContext() context.setdefault(‘media_content’, []) context[‘media_content’].append(attrsD) def _start_media_thumbnail(self, attrsD): context = self._getContext() context.setdefault(‘media_thumbnail’, []) self.push(‘url’, 1) # new context[‘media_thumbnail’].append(attrsD) def _end_media_thumbnail(self): url = self.pop(‘url’) context = self._getContext() if url != None and len(url.strip()) != 0: if ‘url’ not in context[‘media_thumbnail’][-1]: context[‘media_thumbnail’][-1][‘url’] = url def _start_media_player(self, attrsD): self.push(‘media_player’, 0) self._getContext()[‘media_player’] = FeedParserDict(attrsD) def _end_media_player(self): value = self.pop(‘media_player’) context = self._getContext() context[‘media_player’][‘content’] = value def _start_newlocation(self, attrsD): self.push(‘newlocation’, 1) def _end_newlocation(self): url = self.pop(‘newlocation’) context = self._getContext() # don’t set newlocation if the context isn’t right if context is not self.feeddata: return context[‘newlocation’] = _makeSafeAbsoluteURI(self.baseuri, url.strip()) def _start_psc_chapters(self, attrsD): if self.psc_chapters_flag is None: # Transition from None -> True self.psc_chapters_flag = True attrsD[‘chapters’] = [] self._getContext()[‘psc_chapters’] = FeedParserDict(attrsD) def _end_psc_chapters(self): # Transition from True -> False self.psc_chapters_flag = False def _start_psc_chapter(self, attrsD): if self.psc_chapters_flag: start = self._getAttribute(attrsD, ‘start’) attrsD[‘start_parsed’] = _parse_psc_chapter_start(start) context = self._getContext()[‘psc_chapters’] context[‘chapters’].append(FeedParserDict(attrsD)) if _XML_AVAILABLE: class _StrictFeedParser(_FeedParserMixin, xml.sax.handler.ContentHandler): def __init__(self, baseuri, baselang, encoding): xml.sax.handler.ContentHandler.__init__(self) _FeedParserMixin.__init__(self, baseuri, baselang, encoding) self.bozo = 0 self.exc = None self.decls = {} def startPrefixMapping(self, prefix, uri): if not uri: return # Jython uses ” instead of None; standardize on None prefix = prefix or None self.trackNamespace(prefix, uri) if prefix and uri == ‘http://www.w3.org/1999/xlink’: self.decls[‘xmlns:’ + prefix] = uri def startElementNS(self, name, qname, attrs): namespace, localname = name lowernamespace = str(namespace or ”).lower() if lowernamespace.find(‘backend.userland.com/rss’) != -1: # match any backend.userland.com namespace namespace = ‘http://backend.userland.com/rss’ lowernamespace = namespace if qname and qname.find(‘:’) > 0: givenprefix = qname.split(‘:’)[0] else: givenprefix = None prefix = self._matchnamespaces.get(lowernamespace, givenprefix) if givenprefix and (prefix == None or (prefix == ” and lowernamespace == ”)) and givenprefix not in self.namespacesInUse: raise UndeclaredNamespace(“‘%s’ is not associated with a namespace” % givenprefix) localname = str(localname).lower() # qname implementation is horribly broken in Python 2.1 (it # doesn’t report any), and slightly broken in Python 2.2 (it # doesn’t report the xml: namespace). So we match up namespaces # with a known list first, and then possibly override them with # the qnames the SAX parser gives us (if indeed it gives us any # at all). Thanks to MatejC for helping me test this and # tirelessly telling me that it didn’t work yet. attrsD, self.decls = self.decls, {} if localname==’math’ and namespace==’http://www.w3.org/1998/Math/MathML’: attrsD[‘xmlns’]=namespace if localname==’svg’ and namespace==’http://www.w3.org/2000/svg’: attrsD[‘xmlns’]=namespace if prefix: localname = prefix.lower() + ‘:’ + localname elif namespace and not qname: #Expat for name,value in list(self.namespacesInUse.items()): if name and value == namespace: localname = name + ‘:’ + localname break for (namespace, attrlocalname), attrvalue in list(attrs.items()): lowernamespace = (namespace or ”).lower() prefix = self._matchnamespaces.get(lowernamespace, ”) if prefix: attrlocalname = prefix + ‘:’ + attrlocalname attrsD[str(attrlocalname).lower()] = attrvalue for qname in attrs.getQNames(): attrsD[str(qname).lower()] = attrs.getValueByQName(qname) localname = str(localname).lower() self.unknown_starttag(localname, list(attrsD.items())) def characters(self, text): self.handle_data(text) def endElementNS(self, name, qname): namespace, localname = name lowernamespace = str(namespace or ”).lower() if qname and qname.find(‘:’) > 0: givenprefix = qname.split(‘:’)[0] else: givenprefix = ” prefix = self._matchnamespaces.get(lowernamespace, givenprefix) if prefix: localname = prefix + ‘:’ + localname elif namespace and not qname: #Expat for name,value in list(self.namespacesInUse.items()): if name and value == namespace: localname = name + ‘:’ + localname break localname = str(localname).lower() self.unknown_endtag(localname) def error(self, exc): self.bozo = 1 self.exc = exc # drv_libxml2 calls warning() in some cases warning = error def fatalError(self, exc): self.error(exc) raise exc class _BaseHTMLProcessor(sgmllib.SGMLParser): special = re.compile(”'[<>'”]”’) bare_ampersand = re.compile(“&(?!#\d+;|#x[0-9a-fA-F]+;|\w+;)”) elements_no_end_tag = set([ ‘area’, ‘base’, ‘basefont’, ‘br’, ‘col’, ‘command’, ’embed’, ‘frame’, ‘hr’, ‘img’, ‘input’, ‘isindex’, ‘keygen’, ‘link’, ‘meta’, ‘param’, ‘source’, ‘track’, ‘wbr’ ]) def __init__(self, encoding, _type): self.encoding = encoding self._type = _type sgmllib.SGMLParser.__init__(self) def reset(self): self.pieces = [] sgmllib.SGMLParser.reset(self) def _shorttag_replace(self, match): tag = match.group(1) if tag in self.elements_no_end_tag: return ‘<‘ + tag + ‘ />’ else: return ‘<‘ + tag + ‘></’ + tag + ‘>’ # By declaring these methods and overriding their compiled code # with the code from sgmllib, the original code will execute in # feedparser’s scope instead of sgmllib’s. This means that the # `tagfind` and `charref` regular expressions will be found as # they’re declared above, not as they’re declared in sgmllib. def goahead(self, i): pass goahead.__code__ = sgmllib.SGMLParser.goahead.__code__ def __parse_starttag(self, i): pass __parse_starttag.__code__ = sgmllib.SGMLParser.parse_starttag.__code__ def parse_starttag(self,i): j = self.__parse_starttag(i) if self._type == ‘application/xhtml+xml’: if j>2 and self.rawdata[j-2:j]==’/>’: self.unknown_endtag(self.lasttag) return j def feed(self, data): data = re.compile(r'<!((?!DOCTYPE|–|\[))’, re.IGNORECASE).sub(r’&lt;!\1′, data) data = re.sub(r'<([^<>\s]+?)\s*/>’, self._shorttag_replace, data) data = data.replace(‘'’, “‘”) data = data.replace(‘"’, ‘”‘) try: bytes if bytes is str: raise NameError self.encoding = self.encoding + ‘_INVALID_PYTHON_3’ except NameError: if self.encoding and isinstance(data, str): data = data.encode(self.encoding) sgmllib.SGMLParser.feed(self, data) sgmllib.SGMLParser.close(self) def normalize_attrs(self, attrs): if not attrs: return attrs # utility method to be called by descendants attrs = list(dict([(k.lower(), v) for k, v in attrs]).items()) attrs = [(k, k in (‘rel’, ‘type’) and v.lower() or v) for k, v in attrs] attrs.sort() return attrs def unknown_starttag(self, tag, attrs): # called for each start tag # attrs is a list of (attr, value) tuples # e.g. for <pre class=’screen’>, tag=’pre’, attrs=[(‘class’, ‘screen’)] uattrs = [] strattrs=” if attrs: for key, value in attrs: value=value.replace(‘>’,’&gt;’).replace(‘<‘,’&lt;’).replace(‘”‘,’&quot;’) value = self.bare_ampersand.sub(“&amp;”, value) # thanks to Kevin Marks for this breathtaking hack to deal with (valid) high-bit attribute values in UTF-8 feeds if not isinstance(value, str): value = value.decode(self.encoding, ‘ignore’) try: # Currently, in Python 3 the key is already a str, and cannot be decoded again uattrs.append((str(key, self.encoding), value)) except TypeError: uattrs.append((key, value)) strattrs = ”.join([‘ %s=”%s”‘ % (key, value) for key, value in uattrs]) if self.encoding: try: strattrs = strattrs.encode(self.encoding) except (UnicodeEncodeError, LookupError): pass if tag in self.elements_no_end_tag: self.pieces.append(‘<%s%s />’ % (tag, strattrs)) else: self.pieces.append(‘<%s%s>’ % (tag, strattrs)) def unknown_endtag(self, tag): # called for each end tag, e.g. for </pre>, tag will be ‘pre’ # Reconstruct the original end tag. if tag not in self.elements_no_end_tag: self.pieces.append(“</%s>” % tag) def handle_charref(self, ref): # called for each character reference, e.g. for ‘ ’, ref will be ‘160’ # Reconstruct the original character reference. ref = ref.lower() if ref.startswith(‘x’): value = int(ref[1:], 16) else: value = int(ref) if value in _cp1252: self.pieces.append(‘&#%s;’ % hex(ord(_cp1252[value]))[1:]) else: self.pieces.append(‘&#%s;’ % ref) def handle_entityref(self, ref): # called for each entity reference, e.g. for ‘&copy;’, ref will be ‘copy’ # Reconstruct the original entity reference. if ref in name2codepoint or ref == ‘apos’: self.pieces.append(‘&%s;’ % ref) else: self.pieces.append(‘&amp;%s’ % ref) def handle_data(self, text): # called for each block of plain text, i.e. outside of any tag and # not containing any character or entity references # Store the original text verbatim. self.pieces.append(text) def handle_comment(self, text): # called for each HTML comment, e.g. <!– insert Javascript code here –> # Reconstruct the original comment. self.pieces.append(‘<!–%s–>’ % text) def handle_pi(self, text): # called for each processing instruction, e.g. <?instruction> # Reconstruct original processing instruction. self.pieces.append(‘<?%s>’ % text) def handle_decl(self, text): # called for the DOCTYPE, if present, e.g. # <!DOCTYPE html PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN” # “http://www.w3.org/TR/html4/loose.dtd”> # Reconstruct original DOCTYPE self.pieces.append(‘<!%s>’ % text) _new_declname_match = re.compile(r'[a-zA-Z][-_.a-zA-Z0-9:]*\s*’).match def _scan_name(self, i, declstartpos): rawdata = self.rawdata n = len(rawdata) if i == n: return None, -1 m = self._new_declname_match(rawdata, i) if m: s = m.group() name = s.strip() if (i + len(s)) == n: return None, -1 # end of buffer return name.lower(), m.end() else: self.handle_data(rawdata) # self.updatepos(declstartpos, i) return None, -1 def convert_charref(self, name): return ‘&#%s;’ % name def convert_entityref(self, name): return ‘&%s;’ % name def output(self): ”’Return processed HTML as a single string”’ return ”.join([str(p) for p in self.pieces]) def parse_declaration(self, i): try: return sgmllib.SGMLParser.parse_declaration(self, i) except sgmllib.SGMLParseError: # escape the doctype declaration and continue parsing self.handle_data(‘&lt;’) return i+1 class _LooseFeedParser(_FeedParserMixin, _BaseHTMLProcessor): def __init__(self, baseuri, baselang, encoding, entities): sgmllib.SGMLParser.__init__(self) _FeedParserMixin.__init__(self, baseuri, baselang, encoding) _BaseHTMLProcessor.__init__(self, encoding, ‘application/xhtml+xml’) self.entities=entities def decodeEntities(self, element, data): data = data.replace(‘<’, ‘&lt;’) data = data.replace(‘<’, ‘&lt;’) data = data.replace(‘<’, ‘&lt;’) data = data.replace(‘>’, ‘&gt;’) data = data.replace(‘>’, ‘&gt;’) data = data.replace(‘>’, ‘&gt;’) data = data.replace(‘&’, ‘&amp;’) data = data.replace(‘&’, ‘&amp;’) data = data.replace(‘"’, ‘&quot;’) data = data.replace(‘"’, ‘&quot;’) data = data.replace(‘'’, ‘&apos;’) data = data.replace(‘'’, ‘&apos;’) if not self.contentparams.get(‘type’, ‘xml’).endswith(‘xml’): data = data.replace(‘&lt;’, ‘<‘) data = data.replace(‘&gt;’, ‘>’) data = data.replace(‘&amp;’, ‘&’) data = data.replace(‘&quot;’, ‘”‘) data = data.replace(‘&apos;’, “‘”) data = data.replace(‘/’, ‘/’) data = data.replace(‘/’, ‘/’) return data def strattrs(self, attrs): return ”.join([‘ %s=”%s”‘ % (n,v.replace(‘”‘,’&quot;’)) for n,v in attrs]) class _RelativeURIResolver(_BaseHTMLProcessor): relative_uris = set([(‘a’, ‘href’), (‘applet’, ‘codebase’), (‘area’, ‘href’), (‘audio’, ‘src’), (‘blockquote’, ‘cite’), (‘body’, ‘background’), (‘del’, ‘cite’), (‘form’, ‘action’), (‘frame’, ‘longdesc’), (‘frame’, ‘src’), (‘iframe’, ‘longdesc’), (‘iframe’, ‘src’), (‘head’, ‘profile’), (‘img’, ‘longdesc’), (‘img’, ‘src’), (‘img’, ‘usemap’), (‘input’, ‘src’), (‘input’, ‘usemap’), (‘ins’, ‘cite’), (‘link’, ‘href’), (‘object’, ‘classid’), (‘object’, ‘codebase’), (‘object’, ‘data’), (‘object’, ‘usemap’), (‘q’, ‘cite’), (‘script’, ‘src’), (‘source’, ‘src’), (‘video’, ‘poster’), (‘video’, ‘src’)]) def __init__(self, baseuri, encoding, _type): _BaseHTMLProcessor.__init__(self, encoding, _type) self.baseuri = baseuri def resolveURI(self, uri): return _makeSafeAbsoluteURI(self.baseuri, uri.strip()) def unknown_starttag(self, tag, attrs): attrs = self.normalize_attrs(attrs) attrs = [(key, ((tag, key) in self.relative_uris) and self.resolveURI(value) or value) for key, value in attrs] _BaseHTMLProcessor.unknown_starttag(self, tag, attrs) def _resolveRelativeURIs(htmlSource, baseURI, encoding, _type): if not _SGML_AVAILABLE: return htmlSource p = _RelativeURIResolver(baseURI, encoding, _type) p.feed(htmlSource) return p.output() def _makeSafeAbsoluteURI(base, rel=None): # bail if ACCEPTABLE_URI_SCHEMES is empty if not ACCEPTABLE_URI_SCHEMES: return _urljoin(base, rel or ”) if not base: return rel or ” if not rel: try: scheme = urllib.parse.urlparse(base)[0] except ValueError: return ” if not scheme or scheme in ACCEPTABLE_URI_SCHEMES: return base return ” uri = _urljoin(base, rel) if uri.strip().split(‘:’, 1)[0] not in ACCEPTABLE_URI_SCHEMES: return ” return uri class _HTMLSanitizer(_BaseHTMLProcessor): acceptable_elements = set([‘a’, ‘abbr’, ‘acronym’, ‘address’, ‘area’, ‘article’, ‘aside’, ‘audio’, ‘b’, ‘big’, ‘blockquote’, ‘br’, ‘button’, ‘canvas’, ‘caption’, ‘center’, ‘cite’, ‘code’, ‘col’, ‘colgroup’, ‘command’, ‘datagrid’, ‘datalist’, ‘dd’, ‘del’, ‘details’, ‘dfn’, ‘dialog’, ‘dir’, ‘div’, ‘dl’, ‘dt’, ’em’, ‘event-source’, ‘fieldset’, ‘figcaption’, ‘figure’, ‘footer’, ‘font’, ‘form’, ‘header’, ‘h1’, ‘h2’, ‘h3’, ‘h4’, ‘h5’, ‘h6’, ‘hr’, ‘i’, ‘img’, ‘input’, ‘ins’, ‘keygen’, ‘kbd’, ‘label’, ‘legend’, ‘li’, ‘m’, ‘map’, ‘menu’, ‘meter’, ‘multicol’, ‘nav’, ‘nextid’, ‘ol’, ‘output’, ‘optgroup’, ‘option’, ‘p’, ‘pre’, ‘progress’, ‘q’, ‘s’, ‘samp’, ‘section’, ‘select’, ‘small’, ‘sound’, ‘source’, ‘spacer’, ‘span’, ‘strike’, ‘strong’, ‘sub’, ‘sup’, ‘table’, ‘tbody’, ‘td’, ‘textarea’, ‘time’, ‘tfoot’, ‘th’, ‘thead’, ‘tr’, ‘tt’, ‘u’, ‘ul’, ‘var’, ‘video’, ‘noscript’]) acceptable_attributes = set([‘abbr’, ‘accept’, ‘accept-charset’, ‘accesskey’, ‘action’, ‘align’, ‘alt’, ‘autocomplete’, ‘autofocus’, ‘axis’, ‘background’, ‘balance’, ‘bgcolor’, ‘bgproperties’, ‘border’, ‘bordercolor’, ‘bordercolordark’, ‘bordercolorlight’, ‘bottompadding’, ‘cellpadding’, ‘cellspacing’, ‘ch’, ‘challenge’, ‘char’, ‘charoff’, ‘choff’, ‘charset’, ‘checked’, ‘cite’, ‘class’, ‘clear’, ‘color’, ‘cols’, ‘colspan’, ‘compact’, ‘contenteditable’, ‘controls’, ‘coords’, ‘data’, ‘datafld’, ‘datapagesize’, ‘datasrc’, ‘datetime’, ‘default’, ‘delay’, ‘dir’, ‘disabled’, ‘draggable’, ‘dynsrc’, ‘enctype’, ‘end’, ‘face’, ‘for’, ‘form’, ‘frame’, ‘galleryimg’, ‘gutter’, ‘headers’, ‘height’, ‘hidefocus’, ‘hidden’, ‘high’, ‘href’, ‘hreflang’, ‘hspace’, ‘icon’, ‘id’, ‘inputmode’, ‘ismap’, ‘keytype’, ‘label’, ‘leftspacing’, ‘lang’, ‘list’, ‘longdesc’, ‘loop’, ‘loopcount’, ‘loopend’, ‘loopstart’, ‘low’, ‘lowsrc’, ‘max’, ‘maxlength’, ‘media’, ‘method’, ‘min’, ‘multiple’, ‘name’, ‘nohref’, ‘noshade’, ‘nowrap’, ‘open’, ‘optimum’, ‘pattern’, ‘ping’, ‘point-size’, ‘poster’, ‘pqg’, ‘preload’, ‘prompt’, ‘radiogroup’, ‘readonly’, ‘rel’, ‘repeat-max’, ‘repeat-min’, ‘replace’, ‘required’, ‘rev’, ‘rightspacing’, ‘rows’, ‘rowspan’, ‘rules’, ‘scope’, ‘selected’, ‘shape’, ‘size’, ‘span’, ‘src’, ‘start’, ‘step’, ‘summary’, ‘suppress’, ‘tabindex’, ‘target’, ‘template’, ‘title’, ‘toppadding’, ‘type’, ‘unselectable’, ‘usemap’, ‘urn’, ‘valign’, ‘value’, ‘variable’, ‘volume’, ‘vspace’, ‘vrml’, ‘width’, ‘wrap’, ‘xml:lang’]) unacceptable_elements_with_end_tag = set([‘script’, ‘applet’, ‘style’]) acceptable_css_properties = set([‘azimuth’, ‘background-color’, ‘border-bottom-color’, ‘border-collapse’, ‘border-color’, ‘border-left-color’, ‘border-right-color’, ‘border-top-color’, ‘clear’, ‘color’, ‘cursor’, ‘direction’, ‘display’, ‘elevation’, ‘float’, ‘font’, ‘font-family’, ‘font-size’, ‘font-style’, ‘font-variant’, ‘font-weight’, ‘height’, ‘letter-spacing’, ‘line-height’, ‘overflow’, ‘pause’, ‘pause-after’, ‘pause-before’, ‘pitch’, ‘pitch-range’, ‘richness’, ‘speak’, ‘speak-header’, ‘speak-numeral’, ‘speak-punctuation’, ‘speech-rate’, ‘stress’, ‘text-align’, ‘text-decoration’, ‘text-indent’, ‘unicode-bidi’, ‘vertical-align’, ‘voice-family’, ‘volume’, ‘white-space’, ‘width’]) # survey of common keywords found in feeds acceptable_css_keywords = set([‘auto’, ‘aqua’, ‘black’, ‘block’, ‘blue’, ‘bold’, ‘both’, ‘bottom’, ‘brown’, ‘center’, ‘collapse’, ‘dashed’, ‘dotted’, ‘fuchsia’, ‘gray’, ‘green’, ‘!important’, ‘italic’, ‘left’, ‘lime’, ‘maroon’, ‘medium’, ‘none’, ‘navy’, ‘normal’, ‘nowrap’, ‘olive’, ‘pointer’, ‘purple’, ‘red’, ‘right’, ‘solid’, ‘silver’, ‘teal’, ‘top’, ‘transparent’, ‘underline’, ‘white’, ‘yellow’]) valid_css_values = re.compile(‘^(#[0-9a-f]+|rgb\(\d+%?,\d*%?,?\d*%?\)?|’ + ‘\d{0,2}\.?\d{0,2}(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)$’) mathml_elements = set([ ‘annotation’, ‘annotation-xml’, ‘maction’, ‘maligngroup’, ‘malignmark’, ‘math’, ‘menclose’, ‘merror’, ‘mfenced’, ‘mfrac’, ‘mglyph’, ‘mi’, ‘mlabeledtr’, ‘mlongdiv’, ‘mmultiscripts’, ‘mn’, ‘mo’, ‘mover’, ‘mpadded’, ‘mphantom’, ‘mprescripts’, ‘mroot’, ‘mrow’, ‘ms’, ‘mscarries’, ‘mscarry’, ‘msgroup’, ‘msline’, ‘mspace’, ‘msqrt’, ‘msrow’, ‘mstack’, ‘mstyle’, ‘msub’, ‘msubsup’, ‘msup’, ‘mtable’, ‘mtd’, ‘mtext’, ‘mtr’, ‘munder’, ‘munderover’, ‘none’, ‘semantics’, ]) mathml_attributes = set([ ‘accent’, ‘accentunder’, ‘actiontype’, ‘align’, ‘alignmentscope’, ‘altimg’, ‘altimg-height’, ‘altimg-valign’, ‘altimg-width’, ‘alttext’, ‘bevelled’, ‘charalign’, ‘close’, ‘columnalign’, ‘columnlines’, ‘columnspacing’, ‘columnspan’, ‘columnwidth’, ‘crossout’, ‘decimalpoint’, ‘denomalign’, ‘depth’, ‘dir’, ‘display’, ‘displaystyle’, ‘edge’, ‘encoding’, ‘equalcolumns’, ‘equalrows’, ‘fence’, ‘fontstyle’, ‘fontweight’, ‘form’, ‘frame’, ‘framespacing’, ‘groupalign’, ‘height’, ‘href’, ‘id’, ‘indentalign’, ‘indentalignfirst’, ‘indentalignlast’, ‘indentshift’, ‘indentshiftfirst’, ‘indentshiftlast’, ‘indenttarget’, ‘infixlinebreakstyle’, ‘largeop’, ‘length’, ‘linebreak’, ‘linebreakmultchar’, ‘linebreakstyle’, ‘lineleading’, ‘linethickness’, ‘location’, ‘longdivstyle’, ‘lquote’, ‘lspace’, ‘mathbackground’, ‘mathcolor’, ‘mathsize’, ‘mathvariant’, ‘maxsize’, ‘minlabelspacing’, ‘minsize’, ‘movablelimits’, ‘notation’, ‘numalign’, ‘open’, ‘other’, ‘overflow’, ‘position’, ‘rowalign’, ‘rowlines’, ‘rowspacing’, ‘rowspan’, ‘rquote’, ‘rspace’, ‘scriptlevel’, ‘scriptminsize’, ‘scriptsizemultiplier’, ‘selection’, ‘separator’, ‘separators’, ‘shift’, ‘side’, ‘src’, ‘stackalign’, ‘stretchy’, ‘subscriptshift’, ‘superscriptshift’, ‘symmetric’, ‘voffset’, ‘width’, ‘xlink:href’, ‘xlink:show’, ‘xlink:type’, ‘xmlns’, ‘xmlns:xlink’, ]) # svgtiny – foreignObject + linearGradient + radialGradient + stop svg_elements = set([‘a’, ‘animate’, ‘animateColor’, ‘animateMotion’, ‘animateTransform’, ‘circle’, ‘defs’, ‘desc’, ‘ellipse’, ‘foreignObject’, ‘font-face’, ‘font-face-name’, ‘font-face-src’, ‘g’, ‘glyph’, ‘hkern’, ‘linearGradient’, ‘line’, ‘marker’, ‘metadata’, ‘missing-glyph’, ‘mpath’, ‘path’, ‘polygon’, ‘polyline’, ‘radialGradient’, ‘rect’, ‘set’, ‘stop’, ‘svg’, ‘switch’, ‘text’, ‘title’, ‘tspan’, ‘use’]) # svgtiny + class + opacity + offset + xmlns + xmlns:xlink svg_attributes = set([‘accent-height’, ‘accumulate’, ‘additive’, ‘alphabetic’, ‘arabic-form’, ‘ascent’, ‘attributeName’, ‘attributeType’, ‘baseProfile’, ‘bbox’, ‘begin’, ‘by’, ‘calcMode’, ‘cap-height’, ‘class’, ‘color’, ‘color-rendering’, ‘content’, ‘cx’, ‘cy’, ‘d’, ‘dx’, ‘dy’, ‘descent’, ‘display’, ‘dur’, ‘end’, ‘fill’, ‘fill-opacity’, ‘fill-rule’, ‘font-family’, ‘font-size’, ‘font-stretch’, ‘font-style’, ‘font-variant’, ‘font-weight’, ‘from’, ‘fx’, ‘fy’, ‘g1’, ‘g2’, ‘glyph-name’, ‘gradientUnits’, ‘hanging’, ‘height’, ‘horiz-adv-x’, ‘horiz-origin-x’, ‘id’, ‘ideographic’, ‘k’, ‘keyPoints’, ‘keySplines’, ‘keyTimes’, ‘lang’, ‘mathematical’, ‘marker-end’, ‘marker-mid’, ‘marker-start’, ‘markerHeight’, ‘markerUnits’, ‘markerWidth’, ‘max’, ‘min’, ‘name’, ‘offset’, ‘opacity’, ‘orient’, ‘origin’, ‘overline-position’, ‘overline-thickness’, ‘panose-1’, ‘path’, ‘pathLength’, ‘points’, ‘preserveAspectRatio’, ‘r’, ‘refX’, ‘refY’, ‘repeatCount’, ‘repeatDur’, ‘requiredExtensions’, ‘requiredFeatures’, ‘restart’, ‘rotate’, ‘rx’, ‘ry’, ‘slope’, ‘stemh’, ‘stemv’, ‘stop-color’, ‘stop-opacity’, ‘strikethrough-position’, ‘strikethrough-thickness’, ‘stroke’, ‘stroke-dasharray’, ‘stroke-dashoffset’, ‘stroke-linecap’, ‘stroke-linejoin’, ‘stroke-miterlimit’, ‘stroke-opacity’, ‘stroke-width’, ‘systemLanguage’, ‘target’, ‘text-anchor’, ‘to’, ‘transform’, ‘type’, ‘u1’, ‘u2’, ‘underline-position’, ‘underline-thickness’, ‘unicode’, ‘unicode-range’, ‘units-per-em’, ‘values’, ‘version’, ‘viewBox’, ‘visibility’, ‘width’, ‘widths’, ‘x’, ‘x-height’, ‘x1’, ‘x2’, ‘xlink:actuate’, ‘xlink:arcrole’, ‘xlink:href’, ‘xlink:role’, ‘xlink:show’, ‘xlink:title’, ‘xlink:type’, ‘xml:base’, ‘xml:lang’, ‘xml:space’, ‘xmlns’, ‘xmlns:xlink’, ‘y’, ‘y1’, ‘y2’, ‘zoomAndPan’]) svg_attr_map = None svg_elem_map = None acceptable_svg_properties = set([ ‘fill’, ‘fill-opacity’, ‘fill-rule’, ‘stroke’, ‘stroke-width’, ‘stroke-linecap’, ‘stroke-linejoin’, ‘stroke-opacity’]) def reset(self): _BaseHTMLProcessor.reset(self) self.unacceptablestack = 0 self.mathmlOK = 0 self.svgOK = 0 def unknown_starttag(self, tag, attrs): acceptable_attributes = self.acceptable_attributes keymap = {} if not tag in self.acceptable_elements or self.svgOK: if tag in self.unacceptable_elements_with_end_tag: self.unacceptablestack += 1 # add implicit namespaces to html5 inline svg/mathml if self._type.endswith(‘html’): if not dict(attrs).get(‘xmlns’): if tag==’svg’: attrs.append( (‘xmlns’,’http://www.w3.org/2000/svg’) ) if tag==’math’: attrs.append( (‘xmlns’,’http://www.w3.org/1998/Math/MathML’) ) # not otherwise acceptable, perhaps it is MathML or SVG? if tag==’math’ and (‘xmlns’,’http://www.w3.org/1998/Math/MathML’) in attrs: self.mathmlOK += 1 if tag==’svg’ and (‘xmlns’,’http://www.w3.org/2000/svg’) in attrs: self.svgOK += 1 # chose acceptable attributes based on tag class, else bail if self.mathmlOK and tag in self.mathml_elements: acceptable_attributes = self.mathml_attributes elif self.svgOK and tag in self.svg_elements: # for most vocabularies, lowercasing is a good idea. Many # svg elements, however, are camel case if not self.svg_attr_map: lower=[attr.lower() for attr in self.svg_attributes] mix=[a for a in self.svg_attributes if a not in lower] self.svg_attributes = lower self.svg_attr_map = dict([(a.lower(),a) for a in mix]) lower=[attr.lower() for attr in self.svg_elements] mix=[a for a in self.svg_elements if a not in lower] self.svg_elements = lower self.svg_elem_map = dict([(a.lower(),a) for a in mix]) acceptable_attributes = self.svg_attributes tag = self.svg_elem_map.get(tag,tag) keymap = self.svg_attr_map elif not tag in self.acceptable_elements: return # declare xlink namespace, if needed if self.mathmlOK or self.svgOK: if [n_v for n_v in attrs if n_v[0].startswith(‘xlink:’)]: if not (‘xmlns:xlink’,’http://www.w3.org/1999/xlink’) in attrs: attrs.append((‘xmlns:xlink’,’http://www.w3.org/1999/xlink’)) clean_attrs = [] for key, value in self.normalize_attrs(attrs): if key in acceptable_attributes: key=keymap.get(key,key) # make sure the uri uses an acceptable uri scheme if key == ‘href’: value = _makeSafeAbsoluteURI(value) clean_attrs.append((key,value)) elif key==’style’: clean_value = self.sanitize_style(value) if clean_value: clean_attrs.append((key,clean_value)) _BaseHTMLProcessor.unknown_starttag(self, tag, clean_attrs) def unknown_endtag(self, tag): if not tag in self.acceptable_elements: if tag in self.unacceptable_elements_with_end_tag: self.unacceptablestack -= 1 if self.mathmlOK and tag in self.mathml_elements: if tag == ‘math’ and self.mathmlOK: self.mathmlOK -= 1 elif self.svgOK and tag in self.svg_elements: tag = self.svg_elem_map.get(tag,tag) if tag == ‘svg’ and self.svgOK: self.svgOK -= 1 else: return _BaseHTMLProcessor.unknown_endtag(self, tag) def handle_pi(self, text): pass def handle_decl(self, text): pass def handle_data(self, text): if not self.unacceptablestack: _BaseHTMLProcessor.handle_data(self, text) def sanitize_style(self, style): # disallow urls style=re.compile(‘url\s*\(\s*[^\s)]+?\s*\)\s*’).sub(‘ ‘,style) # gauntlet if not re.match(“””^([:,;#%.\sa-zA-Z0-9!]|\w-\w|'[\s\w]+’|”[\s\w]+”|\([\d,\s]+\))*$”””, style): return ” # This replaced a regexp that used re.match and was prone to pathological back-tracking. if re.sub(“\s*[-\w]+\s*:\s*[^:;]*;?”, ”, style).strip(): return ” clean = [] for prop,value in re.findall(“([-\w]+)\s*:\s*([^:;]*)”,style): if not value: continue if prop.lower() in self.acceptable_css_properties: clean.append(prop + ‘: ‘ + value + ‘;’) elif prop.split(‘-‘)[0].lower() in [‘background’,’border’,’margin’,’padding’]: for keyword in value.split(): if not keyword in self.acceptable_css_keywords and \ not self.valid_css_values.match(keyword): break else: clean.append(prop + ‘: ‘ + value + ‘;’) elif self.svgOK and prop.lower() in self.acceptable_svg_properties: clean.append(prop + ‘: ‘ + value + ‘;’) return ‘ ‘.join(clean) def parse_comment(self, i, report=1): ret = _BaseHTMLProcessor.parse_comment(self, i, report) if ret >= 0: return ret # if ret == -1, this may be a malicious attempt to circumvent # sanitization, or a page-destroying unclosed comment match = re.compile(r’–[^>]*>’).search(self.rawdata, i+4) if match: return match.end() # unclosed comment; deliberately fail to handle_data() return len(self.rawdata) def _sanitizeHTML(htmlSource, encoding, _type): if not _SGML_AVAILABLE: return htmlSource p = _HTMLSanitizer(encoding, _type) htmlSource = htmlSource.replace(‘<![CDATA[‘, ‘&lt;![CDATA[‘) p.feed(htmlSource) data = p.output() data = data.strip().replace(‘\r\n’, ‘\n’) return data class _FeedURLHandler(urllib.request.HTTPDigestAuthHandler, urllib.request.HTTPRedirectHandler, urllib.request.HTTPDefaultErrorHandler): def http_error_default(self, req, fp, code, msg, headers): # The default implementation just raises HTTPError. # Forget that. fp.status = code return fp def http_error_301(self, req, fp, code, msg, hdrs): result = urllib.request.HTTPRedirectHandler.http_error_301(self, req, fp, code, msg, hdrs) result.status = code result.newurl = result.geturl() return result # The default implementations in urllib2.HTTPRedirectHandler # are identical, so hardcoding a http_error_301 call above # won’t affect anything http_error_300 = http_error_301 http_error_302 = http_error_301 http_error_303 = http_error_301 http_error_307 = http_error_301 def http_error_401(self, req, fp, code, msg, headers): # Check if # – server requires digest auth, AND # – we tried (unsuccessfully) with basic auth, AND # If all conditions hold, parse authentication information # out of the Authorization header we sent the first time # (for the username and password) and the WWW-Authenticate # header the server sent back (for the realm) and retry # the request with the appropriate digest auth headers instead. # This evil genius hack has been brought to you by Aaron Swartz. host = urllib.parse.urlparse(req.get_full_url())[1] if base64 is None or ‘Authorization’ not in req.headers \ or ‘WWW-Authenticate’ not in headers: return self.http_error_default(req, fp, code, msg, headers) auth = _base64decode(req.headers[‘Authorization’].split(‘ ‘)[1]) user, passw = auth.split(‘:’) realm = re.findall(‘realm=”([^”]*)”‘, headers[‘WWW-Authenticate’])[0] self.add_password(realm, host, user, passw) retry = self.http_error_auth_reqed(‘www-authenticate’, host, req, headers) self.reset_retry_count() return retry def _open_resource(url_file_stream_or_string, etag, modified, agent, referrer, handlers, request_headers): “””URL, filename, or string –> stream This function lets you define parsers that take any input source (URL, pathname to local or network file, or actual data as a string) and deal with it in a uniform manner. Returned object is guaranteed to have all the basic stdio read methods (read, readline, readlines). Just .close() the object when you’re done with it. If the etag argument is supplied, it will be used as the value of an If-None-Match request header. If the modified argument is supplied, it can be a tuple of 9 integers (as returned by gmtime() in the standard Python time module) or a date string in any format supported by feedparser. Regardless, it MUST be in GMT (Greenwich Mean Time). It will be reformatted into an RFC 1123-compliant date and used as the value of an If-Modified-Since request header. If the agent argument is supplied, it will be used as the value of a User-Agent request header. If the referrer argument is supplied, it will be used as the value of a Referer[sic] request header. If handlers is supplied, it is a list of handlers used to build a urllib2 opener. if request_headers is supplied it is a dictionary of HTTP request headers that will override the values generated by FeedParser. :return: A :class:`StringIO.StringIO` or :class:`io.BytesIO`. “”” if hasattr(url_file_stream_or_string, ‘read’): return url_file_stream_or_string if isinstance(url_file_stream_or_string, str) \ and urllib.parse.urlparse(url_file_stream_or_string)[0] in (‘http’, ‘https’, ‘ftp’, ‘file’, ‘feed’): # Deal with the feed URI scheme if url_file_stream_or_string.startswith(‘feed:http’): url_file_stream_or_string = url_file_stream_or_string[5:] elif url_file_stream_or_string.startswith(‘feed:’): url_file_stream_or_string = ‘http:’ + url_file_stream_or_string[5:] if not agent: agent = USER_AGENT # Test for inline user:password credentials for HTTP basic auth auth = None if base64 and not url_file_stream_or_string.startswith(‘ftp:’): urltype, rest = urllib.parse.splittype(url_file_stream_or_string) realhost, rest = urllib.parse.splithost(rest) if realhost: user_passwd, realhost = urllib.parse.splituser(realhost) if user_passwd: url_file_stream_or_string = ‘%s://%s%s’ % (urltype, realhost, rest) auth = base64.standard_b64encode(user_passwd).strip() # iri support if isinstance(url_file_stream_or_string, str): url_file_stream_or_string = _convert_to_idn(url_file_stream_or_string) # try to open with urllib2 (to use optional headers) request = _build_urllib2_request(url_file_stream_or_string, agent, etag, modified, referrer, auth, request_headers) opener = urllib.request.build_opener(*tuple(handlers + [_FeedURLHandler()])) opener.addheaders = [] # RMK – must clear so we only send our custom User-Agent try: return opener.open(request) finally: opener.close() # JohnD # try to open with native open function (if url_file_stream_or_string is a filename) try: return open(url_file_stream_or_string, ‘rb’) except (IOError, UnicodeEncodeError, TypeError): # if url_file_stream_or_string is a unicode object that # cannot be converted to the encoding returned by # sys.getfilesystemencoding(), a UnicodeEncodeError # will be thrown # If url_file_stream_or_string is a string that contains NULL # (such as an XML document encoded in UTF-32), TypeError will # be thrown. pass # treat url_file_stream_or_string as string if isinstance(url_file_stream_or_string, str): return _StringIO(url_file_stream_or_string.encode(‘utf-8’)) return _StringIO(url_file_stream_or_string) def _convert_to_idn(url): “””Convert a URL to IDN notation””” # this function should only be called with a unicode string # strategy: if the host cannot be encoded in ascii, then # it’ll be necessary to encode it in idn form parts = list(urllib.parse.urlsplit(url)) try: parts[1].encode(‘ascii’) except UnicodeEncodeError: # the url needs to be converted to idn notation host = parts[1].rsplit(‘:’, 1) newhost = [] port = ” if len(host) == 2: port = host.pop() for h in host[0].split(‘.’): newhost.append(h.encode(‘idna’).decode(‘utf-8’)) parts[1] = ‘.’.join(newhost) if port: parts[1] += ‘:’ + port return urllib.parse.urlunsplit(parts) else: return url def _build_urllib2_request(url, agent, etag, modified, referrer, auth, request_headers): request = urllib.request.Request(url) request.add_header(‘User-Agent’, agent) if etag: request.add_header(‘If-None-Match’, etag) if isinstance(modified, str): modified = _parse_date(modified) elif isinstance(modified, datetime.datetime): modified = modified.utctimetuple() if modified: # format into an RFC 1123-compliant timestamp. We can’t use # time.strftime() since the %a and %b directives can be affected # by the current locale, but RFC 2616 states that dates must be # in English. short_weekdays = [‘Mon’, ‘Tue’, ‘Wed’, ‘Thu’, ‘Fri’, ‘Sat’, ‘Sun’] months = [‘Jan’, ‘Feb’, ‘Mar’, ‘Apr’, ‘May’, ‘Jun’, ‘Jul’, ‘Aug’, ‘Sep’, ‘Oct’, ‘Nov’, ‘Dec’] request.add_header(‘If-Modified-Since’, ‘%s, %02d %s %04d %02d:%02d:%02d GMT’ % (short_weekdays[modified[6]], modified[2], months[modified[1] – 1], modified[0], modified[3], modified[4], modified[5])) if referrer: request.add_header(‘Referer’, referrer) if gzip and zlib: request.add_header(‘Accept-encoding’, ‘gzip, deflate’) elif gzip: request.add_header(‘Accept-encoding’, ‘gzip’) elif zlib: request.add_header(‘Accept-encoding’, ‘deflate’) else: request.add_header(‘Accept-encoding’, ”) if auth: request.add_header(‘Authorization’, ‘Basic %s’ % auth) if ACCEPT_HEADER: request.add_header(‘Accept’, ACCEPT_HEADER) # use this for whatever — cookies, special headers, etc # [(‘Cookie’,’Something’),(‘x-special-header’,’Another Value’)] for header_name, header_value in list(request_headers.items()): request.add_header(header_name, header_value) request.add_header(‘A-IM’, ‘feed’) # RFC 3229 support return request def _parse_psc_chapter_start(start): FORMAT = r’^((\d{2}):)?(\d{2}):(\d{2})(\.(\d{3}))?$’ m = re.compile(FORMAT).match(start) if m is None: return None _, h, m, s, _, ms = m.groups() h, m, s, ms = (int(h or 0), int(m), int(s), int(ms or 0)) return datetime.timedelta(0, h*60*60 + m*60 + s, ms*1000) _date_handlers = [] def registerDateHandler(func): ”’Register a date handler function (takes string, returns 9-tuple date in GMT)”’ _date_handlers.insert(0, func) # ISO-8601 date parsing routines written by Fazal Majid. # The ISO 8601 standard is very convoluted and irregular – a full ISO 8601 # parser is beyond the scope of feedparser and would be a worthwhile addition # to the Python library. # A single regular expression cannot parse ISO 8601 date formats into groups # as the standard is highly irregular (for instance is 030104 2003-01-04 or # 0301-04-01), so we use templates instead. # Please note the order in templates is significant because we need a # greedy match. _iso8601_tmpl = [‘YYYY-?MM-?DD’, ‘YYYY-0MM?-?DD’, ‘YYYY-MM’, ‘YYYY-?OOO’, ‘YY-?MM-?DD’, ‘YY-?OOO’, ‘YYYY’, ‘-YY-?MM’, ‘-OOO’, ‘-YY’, ‘–MM-?DD’, ‘–MM’, ‘—DD’, ‘CC’, ”] _iso8601_re = [ tmpl.replace( ‘YYYY’, r'(?P<year>\d{4})’).replace( ‘YY’, r'(?P<year>\d\d)’).replace( ‘MM’, r'(?P<month>[01]\d)’).replace( ‘DD’, r'(?P<day>[0123]\d)’).replace( ‘OOO’, r'(?P<ordinal>[0123]\d\d)’).replace( ‘CC’, r'(?P<century>\d\d$)’) + r'(T?(?P<hour>\d{2}):(?P<minute>\d{2})’ + r'(:(?P<second>\d{2}))?’ + r'(\.(?P<fracsecond>\d+))?’ + r'(?P<tz>[+-](?P<tzhour>\d{2})(:(?P<tzmin>\d{2}))?|Z)?)?’ for tmpl in _iso8601_tmpl] try: del tmpl except NameError: pass _iso8601_matches = [re.compile(regex).match for regex in _iso8601_re] try: del regex except NameError: pass def _parse_date_iso8601(dateString): ”’Parse a variety of ISO-8601-compatible formats like 20040105”’ m = None for _iso8601_match in _iso8601_matches: m = _iso8601_match(dateString) if m: break if not m: return if m.span() == (0, 0): return params = m.groupdict() ordinal = params.get(‘ordinal’, 0) if ordinal: ordinal = int(ordinal) else: ordinal = 0 year = params.get(‘year’, ‘–‘) if not year or year == ‘–‘: year = time.gmtime()[0] elif len(year) == 2: # ISO 8601 assumes current century, i.e. 93 -> 2093, NOT 1993 year = 100 * int(time.gmtime()[0] / 100) + int(year) else: year = int(year) month = params.get(‘month’, ‘-‘) if not month or month == ‘-‘: # ordinals are NOT normalized by mktime, we simulate them # by setting month=1, day=ordinal if ordinal: month = 1 else: month = time.gmtime()[1] month = int(month) day = params.get(‘day’, 0) if not day: # see above if ordinal: day = ordinal elif params.get(‘century’, 0) or \ params.get(‘year’, 0) or params.get(‘month’, 0): day = 1 else: day = time.gmtime()[2] else: day = int(day) # special case of the century – is the first year of the 21st century # 2000 or 2001 ? The debate goes on… if ‘century’ in params: year = (int(params[‘century’]) – 1) * 100 + 1 # in ISO 8601 most fields are optional for field in [‘hour’, ‘minute’, ‘second’, ‘tzhour’, ‘tzmin’]: if not params.get(field, None): params[field] = 0 hour = int(params.get(‘hour’, 0)) minute = int(params.get(‘minute’, 0)) second = int(float(params.get(‘second’, 0))) # weekday is normalized by mktime(), we can ignore it weekday = 0 daylight_savings_flag = -1 tm = [year, month, day, hour, minute, second, weekday, ordinal, daylight_savings_flag] # ISO 8601 time zone adjustments tz = params.get(‘tz’) if tz and tz != ‘Z’: if tz[0] == ‘-‘: tm[3] += int(params.get(‘tzhour’, 0)) tm[4] += int(params.get(‘tzmin’, 0)) elif tz[0] == ‘+’: tm[3] -= int(params.get(‘tzhour’, 0)) tm[4] -= int(params.get(‘tzmin’, 0)) else: return None # Python’s time.mktime() is a wrapper around the ANSI C mktime(3c) # which is guaranteed to normalize d/m/y/h/m/s. # Many implementations have bugs, but we’ll pretend they don’t. return time.localtime(time.mktime(tuple(tm))) registerDateHandler(_parse_date_iso8601) # 8-bit date handling routines written by ytrewq1. _korean_year = ‘\ub144’ # b3e2 in euc-kr _korean_month = ‘\uc6d4’ # bff9 in euc-kr _korean_day = ‘\uc77c’ # c0cf in euc-kr _korean_am = ‘\uc624\uc804’ # bfc0 c0fc in euc-kr _korean_pm = ‘\uc624\ud6c4’ # bfc0 c8c4 in euc-kr _korean_onblog_date_re = \ re.compile(‘(\d{4})%s\s+(\d{2})%s\s+(\d{2})%s\s+(\d{2}):(\d{2}):(\d{2})’ % \ (_korean_year, _korean_month, _korean_day)) _korean_nate_date_re = \ re.compile(‘(\d{4})-(\d{2})-(\d{2})\s+(%s|%s)\s+(\d{,2}):(\d{,2}):(\d{,2})’ % \ (_korean_am, _korean_pm)) def _parse_date_onblog(dateString): ”’Parse a string according to the OnBlog 8-bit date format”’ m = _korean_onblog_date_re.match(dateString) if not m: return w3dtfdate = ‘%(year)s-%(month)s-%(day)sT%(hour)s:%(minute)s:%(second)s%(zonediff)s’ % \ {‘year’: m.group(1), ‘month’: m.group(2), ‘day’: m.group(3),\ ‘hour’: m.group(4), ‘minute’: m.group(5), ‘second’: m.group(6),\ ‘zonediff’: ‘+09:00′} return _parse_date_w3dtf(w3dtfdate) registerDateHandler(_parse_date_onblog) def _parse_date_nate(dateString): ”’Parse a string according to the Nate 8-bit date format”’ m = _korean_nate_date_re.match(dateString) if not m: return hour = int(m.group(5)) ampm = m.group(4) if (ampm == _korean_pm): hour += 12 hour = str(hour) if len(hour) == 1: hour = ‘0’ + hour w3dtfdate = ‘%(year)s-%(month)s-%(day)sT%(hour)s:%(minute)s:%(second)s%(zonediff)s’ % \ {‘year’: m.group(1), ‘month’: m.group(2), ‘day’: m.group(3),\ ‘hour’: hour, ‘minute’: m.group(6), ‘second’: m.group(7),\ ‘zonediff’: ‘+09:00’} return _parse_date_w3dtf(w3dtfdate) registerDateHandler(_parse_date_nate) # Unicode strings for Greek date strings _greek_months = \ { \ ‘\u0399\u03b1\u03bd’: ‘Jan’, # c9e1ed in iso-8859-7 ‘\u03a6\u03b5\u03b2’: ‘Feb’, # d6e5e2 in iso-8859-7 ‘\u039c\u03ac\u03ce’: ‘Mar’, # ccdcfe in iso-8859-7 ‘\u039c\u03b1\u03ce’: ‘Mar’, # cce1fe in iso-8859-7 ‘\u0391\u03c0\u03c1’: ‘Apr’, # c1f0f1 in iso-8859-7 ‘\u039c\u03ac\u03b9’: ‘May’, # ccdce9 in iso-8859-7 ‘\u039c\u03b1\u03ca’: ‘May’, # cce1fa in iso-8859-7 ‘\u039c\u03b1\u03b9’: ‘May’, # cce1e9 in iso-8859-7 ‘\u0399\u03bf\u03cd\u03bd’: ‘Jun’, # c9effded in iso-8859-7 ‘\u0399\u03bf\u03bd’: ‘Jun’, # c9efed in iso-8859-7 ‘\u0399\u03bf\u03cd\u03bb’: ‘Jul’, # c9effdeb in iso-8859-7 ‘\u0399\u03bf\u03bb’: ‘Jul’, # c9f9eb in iso-8859-7 ‘\u0391\u03cd\u03b3’: ‘Aug’, # c1fde3 in iso-8859-7 ‘\u0391\u03c5\u03b3’: ‘Aug’, # c1f5e3 in iso-8859-7 ‘\u03a3\u03b5\u03c0’: ‘Sep’, # d3e5f0 in iso-8859-7 ‘\u039f\u03ba\u03c4’: ‘Oct’, # cfeaf4 in iso-8859-7 ‘\u039d\u03bf\u03ad’: ‘Nov’, # cdefdd in iso-8859-7 ‘\u039d\u03bf\u03b5’: ‘Nov’, # cdefe5 in iso-8859-7 ‘\u0394\u03b5\u03ba’: ‘Dec’, # c4e5ea in iso-8859-7 } _greek_wdays = \ { \ ‘\u039a\u03c5\u03c1’: ‘Sun’, # caf5f1 in iso-8859-7 ‘\u0394\u03b5\u03c5’: ‘Mon’, # c4e5f5 in iso-8859-7 ‘\u03a4\u03c1\u03b9’: ‘Tue’, # d4f1e9 in iso-8859-7 ‘\u03a4\u03b5\u03c4’: ‘Wed’, # d4e5f4 in iso-8859-7 ‘\u03a0\u03b5\u03bc’: ‘Thu’, # d0e5ec in iso-8859-7 ‘\u03a0\u03b1\u03c1’: ‘Fri’, # d0e1f1 in iso-8859-7 ‘\u03a3\u03b1\u03b2’: ‘Sat’, # d3e1e2 in iso-8859-7 } _greek_date_format_re = \ re.compile(‘([^,]+),\s+(\d{2})\s+([^\s]+)\s+(\d{4})\s+(\d{2}):(\d{2}):(\d{2})\s+([^\s]+)’) def _parse_date_greek(dateString): ”’Parse a string according to a Greek 8-bit date format.”’ m = _greek_date_format_re.match(dateString) if not m: return wday = _greek_wdays[m.group(1)] month = _greek_months[m.group(3)] rfc822date = ‘%(wday)s, %(day)s %(month)s %(year)s %(hour)s:%(minute)s:%(second)s %(zonediff)s’ % \ {‘wday’: wday, ‘day’: m.group(2), ‘month’: month, ‘year’: m.group(4),\ ‘hour’: m.group(5), ‘minute’: m.group(6), ‘second’: m.group(7),\ ‘zonediff’: m.group(8)} return _parse_date_rfc822(rfc822date) registerDateHandler(_parse_date_greek) # Unicode strings for Hungarian date strings _hungarian_months = \ { \ ‘janu\u00e1r’: ’01’, # e1 in iso-8859-2 ‘febru\u00e1ri’: ’02’, # e1 in iso-8859-2 ‘m\u00e1rcius’: ’03’, # e1 in iso-8859-2 ‘\u00e1prilis’: ’04’, # e1 in iso-8859-2 ‘m\u00e1ujus’: ’05’, # e1 in iso-8859-2 ‘j\u00fanius’: ’06’, # fa in iso-8859-2 ‘j\u00falius’: ’07’, # fa in iso-8859-2 ‘augusztus’: ’08’, ‘szeptember’: ’09’, ‘okt\u00f3ber’: ’10’, # f3 in iso-8859-2 ‘november’: ’11’, ‘december’: ’12’, } _hungarian_date_format_re = \ re.compile(‘(\d{4})-([^-]+)-(\d{,2})T(\d{,2}):(\d{2})((\+|-)(\d{,2}:\d{2}))’) def _parse_date_hungarian(dateString): ”’Parse a string according to a Hungarian 8-bit date format.”’ m = _hungarian_date_format_re.match(dateString) if not m or m.group(2) not in _hungarian_months: return None month = _hungarian_months[m.group(2)] day = m.group(3) if len(day) == 1: day = ‘0’ + day hour = m.group(4) if len(hour) == 1: hour = ‘0’ + hour w3dtfdate = ‘%(year)s-%(month)s-%(day)sT%(hour)s:%(minute)s%(zonediff)s’ % \ {‘year’: m.group(1), ‘month’: month, ‘day’: day,\ ‘hour’: hour, ‘minute’: m.group(5),\ ‘zonediff’: m.group(6)} return _parse_date_w3dtf(w3dtfdate) registerDateHandler(_parse_date_hungarian) timezonenames = { ‘ut’: 0, ‘gmt’: 0, ‘z’: 0, ‘adt’: -3, ‘ast’: -4, ‘at’: -4, ‘edt’: -4, ‘est’: -5, ‘et’: -5, ‘cdt’: -5, ‘cst’: -6, ‘ct’: -6, ‘mdt’: -6, ‘mst’: -7, ‘mt’: -7, ‘pdt’: -7, ‘pst’: -8, ‘pt’: -8, ‘a’: -1, ‘n’: 1, ‘m’: -12, ‘y’: 12, } # W3 date and time format parser # http://www.w3.org/TR/NOTE-datetime # Also supports MSSQL-style datetimes as defined at: # http://msdn.microsoft.com/en-us/library/ms186724.aspx # (basically, allow a space as a date/time/timezone separator) def _parse_date_w3dtf(datestr): if not datestr.strip(): return None parts = datestr.lower().split(‘t’) if len(parts) == 1: # This may be a date only, or may be an MSSQL-style date parts = parts[0].split() if len(parts) == 1: # Treat this as a date only parts.append(’00:00:00z’) elif len(parts) > 2: return None date = parts[0].split(‘-‘, 2) if not date or len(date[0]) != 4: return None # Ensure that `date` has 3 elements. Using ‘1’ sets the default # month to January and the default day to the 1st of the month. date.extend([‘1’] * (3 – len(date))) try: year, month, day = [int(i) for i in date] except ValueError: # `date` may have more than 3 elements or may contain # non-integer strings. return None if parts[1].endswith(‘z’): parts[1] = parts[1][:-1] parts.append(‘z’) # Append the numeric timezone offset, if any, to parts. # If this is an MSSQL-style date then parts[2] already contains # the timezone information, so `append()` will not affect it. # Add 1 to each value so that if `find()` returns -1 it will be # treated as False. loc = parts[1].find(‘-‘) + 1 or parts[1].find(‘+’) + 1 or len(parts[1]) + 1 loc = loc – 1 parts.append(parts[1][loc:]) parts[1] = parts[1][:loc] time = parts[1].split(‘:’, 2) # Ensure that time has 3 elements. Using ‘0’ means that the # minutes and seconds, if missing, will default to 0. time.extend([‘0’] * (3 – len(time))) tzhour = 0 tzmin = 0 if parts[2][:1] in (‘-‘, ‘+’): try: tzhour = int(parts[2][1:3]) tzmin = int(parts[2][4:]) except ValueError: return None if parts[2].startswith(‘-‘): tzhour = tzhour * -1 tzmin = tzmin * -1 else: tzhour = timezonenames.get(parts[2], 0) try: hour, minute, second = [int(float(i)) for i in time] except ValueError: return None # Create the datetime object and timezone delta objects try: stamp = datetime.datetime(year, month, day, hour, minute, second) except ValueError: return None delta = datetime.timedelta(0, 0, 0, 0, tzmin, tzhour) # Return the date and timestamp in a UTC 9-tuple try: return (stamp – delta).utctimetuple() except (OverflowError, ValueError): # IronPython throws ValueErrors instead of OverflowErrors return None registerDateHandler(_parse_date_w3dtf) def _parse_date_rfc822(date): “””Parse RFC 822 dates and times http://tools.ietf.org/html/rfc822#section-5 There are some formatting differences that are accounted for: 1. Years may be two or four digits. 2. The month and day can be swapped. 3. Additional timezone names are supported. 4. A default time and timezone are assumed if only a date is present. “”” daynames = set([‘mon’, ‘tue’, ‘wed’, ‘thu’, ‘fri’, ‘sat’, ‘sun’]) months = { ‘jan’: 1, ‘feb’: 2, ‘mar’: 3, ‘apr’: 4, ‘may’: 5, ‘jun’: 6, ‘jul’: 7, ‘aug’: 8, ‘sep’: 9, ‘oct’: 10, ‘nov’: 11, ‘dec’: 12, } parts = date.lower().split() if len(parts) < 5: # Assume that the time and timezone are missing parts.extend((’00:00:00′, ‘0000’)) # Remove the day name if parts[0][:3] in daynames: parts = parts[1:] if len(parts) < 5: # If there are still fewer than five parts, there’s not enough # information to interpret this return None try: day = int(parts[0]) except ValueError: # Check if the day and month are swapped if months.get(parts[0][:3]): try: day = int(parts[1]) except ValueError: return None else: parts[1] = parts[0] else: return None month = months.get(parts[1][:3]) if not month: return None try: year = int(parts[2]) except ValueError: return None # Normalize two-digit years: # Anything in the 90’s is interpreted as 1990 and on # Anything 89 or less is interpreted as 2089 or before if len(parts[2]) <= 2: year += (1900, 2000)[year < 90] timeparts = parts[3].split(‘:’) timeparts = timeparts + ([0] * (3 – len(timeparts))) try: (hour, minute, second) = list(map(int, timeparts)) except ValueError: return None tzhour = 0 tzmin = 0 # Strip ‘Etc/’ from the timezone if parts[4].startswith(‘etc/’): parts[4] = parts[4][4:] # Normalize timezones that start with ‘gmt’: # GMT-05:00 => -0500 # GMT => GMT if parts[4].startswith(‘gmt’): parts[4] = ”.join(parts[4][3:].split(‘:’)) or ‘gmt’ # Handle timezones like ‘-0500’, ‘+0500’, and ‘EST’ if parts[4] and parts[4][0] in (‘-‘, ‘+’): try: tzhour = int(parts[4][1:3]) tzmin = int(parts[4][3:]) except ValueError: return None if parts[4].startswith(‘-‘): tzhour = tzhour * -1 tzmin = tzmin * -1 else: tzhour = timezonenames.get(parts[4], 0) # Create the datetime object and timezone delta objects try: stamp = datetime.datetime(year, month, day, hour, minute, second) except ValueError: return None delta = datetime.timedelta(0, 0, 0, 0, tzmin, tzhour) # Return the date and timestamp in a UTC 9-tuple try: return (stamp – delta).utctimetuple() except (OverflowError, ValueError): # IronPython throws ValueErrors instead of OverflowErrors return None registerDateHandler(_parse_date_rfc822) _months = [‘jan’, ‘feb’, ‘mar’, ‘apr’, ‘may’, ‘jun’, ‘jul’, ‘aug’, ‘sep’, ‘oct’, ‘nov’, ‘dec’] def _parse_date_asctime(dt): “””Parse asctime-style dates. Converts asctime to RFC822-compatible dates and uses the RFC822 parser to do the actual parsing. Supported formats (format is standardized to the first one listed): * {weekday name} {month name} dd hh:mm:ss {+-tz} yyyy * {weekday name} {month name} dd hh:mm:ss yyyy “”” parts = dt.split() # Insert a GMT timezone, if needed. if len(parts) == 5: parts.insert(4, ‘+0000’) # Exit if there are not six parts. if len(parts) != 6: return None # Reassemble the parts in an RFC822-compatible order and parse them. return _parse_date_rfc822(‘ ‘.join([ parts[0], parts[2], parts[1], parts[5], parts[3], parts[4], ])) registerDateHandler(_parse_date_asctime) def _parse_date_perforce(aDateString): “””parse a date in yyyy/mm/dd hh:mm:ss TTT format””” # Fri, 2006/09/15 08:19:53 EDT _my_date_pattern = re.compile( \ r'(\w{,3}), (\d{,4})/(\d{,2})/(\d{2}) (\d{,2}):(\d{2}):(\d{2}) (\w{,3})’) m = _my_date_pattern.search(aDateString) if m is None: return None dow, year, month, day, hour, minute, second, tz = m.groups() months = [‘Jan’, ‘Feb’, ‘Mar’, ‘Apr’, ‘May’, ‘Jun’, ‘Jul’, ‘Aug’, ‘Sep’, ‘Oct’, ‘Nov’, ‘Dec’] dateString = “%s, %s %s %s %s:%s:%s %s” % (dow, day, months[int(month) – 1], year, hour, minute, second, tz) tm = rfc822.parsedate_tz(dateString) if tm: return time.gmtime(rfc822.mktime_tz(tm)) registerDateHandler(_parse_date_perforce) def _parse_date(dateString): ”’Parses a variety of date formats into a 9-tuple in GMT”’ if not dateString: return None for handler in _date_handlers: try: date9tuple = handler(dateString) except (KeyError, OverflowError, ValueError): continue if not date9tuple: continue if len(date9tuple) != 9: continue return date9tuple return None # Each marker represents some of the characters of the opening XML # processing instruction (‘<?xm’) in the specified encoding. EBCDIC_MARKER = _l2bytes([0x4C, 0x6F, 0xA7, 0x94]) UTF16BE_MARKER = _l2bytes([0x00, 0x3C, 0x00, 0x3F]) UTF16LE_MARKER = _l2bytes([0x3C, 0x00, 0x3F, 0x00]) UTF32BE_MARKER = _l2bytes([0x00, 0x00, 0x00, 0x3C]) UTF32LE_MARKER = _l2bytes([0x3C, 0x00, 0x00, 0x00]) ZERO_BYTES = _l2bytes([0x00, 0x00]) # Match the opening XML declaration. # Example: <?xml version=”1.0″ encoding=”utf-8″?> RE_XML_DECLARATION = re.compile(‘^<\?xml[^>]*?>’) # Capture the value of the XML processing instruction’s encoding attribute. # Example: <?xml version=”1.0″ encoding=”utf-8″?> RE_XML_PI_ENCODING = re.compile(_s2bytes(‘^<\?.*encoding=[\'”](.*?)[\'”].*\?>’)) def convert_to_utf8(http_headers, data): ”’Detect and convert the character encoding to UTF-8. http_headers is a dictionary data is a raw string (not Unicode)”’ # This is so much trickier than it sounds, it’s not even funny. # According to RFC 3023 (‘XML Media Types’), if the HTTP Content-Type # is application/xml, application/*+xml, # application/xml-external-parsed-entity, or application/xml-dtd, # the encoding given in the charset parameter of the HTTP Content-Type # takes precedence over the encoding given in the XML prefix within the # document, and defaults to ‘utf-8’ if neither are specified. But, if # the HTTP Content-Type is text/xml, text/*+xml, or # text/xml-external-parsed-entity, the encoding given in the XML prefix # within the document is ALWAYS IGNORED and only the encoding given in # the charset parameter of the HTTP Content-Type header should be # respected, and it defaults to ‘us-ascii’ if not specified. # Furthermore, discussion on the atom-syntax mailing list with the # author of RFC 3023 leads me to the conclusion that any document # served with a Content-Type of text/* and no charset parameter # must be treated as us-ascii. (We now do this.) And also that it # must always be flagged as non-well-formed. (We now do this too.) # If Content-Type is unspecified (input was local file or non-HTTP source) # or unrecognized (server just got it totally wrong), then go by the # encoding given in the XML prefix of the document and default to # ‘iso-8859-1’ as per the HTTP specification (RFC 2616). # Then, assuming we didn’t find a character encoding in the HTTP headers # (and the HTTP Content-type allowed us to look in the body), we need # to sniff the first few bytes of the XML data and try to determine # whether the encoding is ASCII-compatible. Section F of the XML # specification shows the way here: # http://www.w3.org/TR/REC-xml/#sec-guessing-no-ext-info # If the sniffed encoding is not ASCII-compatible, we need to make it # ASCII compatible so that we can sniff further into the XML declaration # to find the encoding attribute, which will tell us the true encoding. # Of course, none of this guarantees that we will be able to parse the # feed in the declared character encoding (assuming it was declared # correctly, which many are not). iconv_codec can help a lot; # you should definitely install it if you can. # http://cjkpython.i18n.org/ bom_encoding = ” xml_encoding = ” rfc3023_encoding = ” # Look at the first few bytes of the document to guess what # its encoding may be. We only need to decode enough of the # document that we can use an ASCII-compatible regular # expression to search for an XML encoding declaration. # The heuristic follows the XML specification, section F: # http://www.w3.org/TR/REC-xml/#sec-guessing-no-ext-info # Check for BOMs first. if data[:4] == codecs.BOM_UTF32_BE: bom_encoding = ‘utf-32be’ data = data[4:] elif data[:4] == codecs.BOM_UTF32_LE: bom_encoding = ‘utf-32le’ data = data[4:] elif data[:2] == codecs.BOM_UTF16_BE and data[2:4] != ZERO_BYTES: bom_encoding = ‘utf-16be’ data = data[2:] elif data[:2] == codecs.BOM_UTF16_LE and data[2:4] != ZERO_BYTES: bom_encoding = ‘utf-16le’ data = data[2:] elif data[:3] == codecs.BOM_UTF8: bom_encoding = ‘utf-8’ data = data[3:] # Check for the characters ‘<?xm’ in several encodings. elif data[:4] == EBCDIC_MARKER: bom_encoding = ‘cp037’ elif data[:4] == UTF16BE_MARKER: bom_encoding = ‘utf-16be’ elif data[:4] == UTF16LE_MARKER: bom_encoding = ‘utf-16le’ elif data[:4] == UTF32BE_MARKER: bom_encoding = ‘utf-32be’ elif data[:4] == UTF32LE_MARKER: bom_encoding = ‘utf-32le’ tempdata = data try: if bom_encoding: tempdata = data.decode(bom_encoding).encode(‘utf-8’) except (UnicodeDecodeError, LookupError): # feedparser recognizes UTF-32 encodings that aren’t # available in Python 2.4 and 2.5, so it’s possible to # encounter a LookupError during decoding. xml_encoding_match = None else: xml_encoding_match = RE_XML_PI_ENCODING.match(tempdata) if xml_encoding_match: xml_encoding = xml_encoding_match.groups()[0].decode(‘utf-8’).lower() # Normalize the xml_encoding if necessary. if bom_encoding and (xml_encoding in ( ‘u16’, ‘utf-16’, ‘utf16’, ‘utf_16’, ‘u32’, ‘utf-32’, ‘utf32’, ‘utf_32’, ‘iso-10646-ucs-2’, ‘iso-10646-ucs-4’, ‘csucs4’, ‘csunicode’, ‘ucs-2’, ‘ucs-4’ )): xml_encoding = bom_encoding # Find the HTTP Content-Type and, hopefully, a character # encoding provided by the server. The Content-Type is used # to choose the “correct” encoding among the BOM encoding, # XML declaration encoding, and HTTP encoding, following the # heuristic defined in RFC 3023. http_content_type = http_headers.get(‘content-type’) or ” http_content_type, params = cgi.parse_header(http_content_type) http_encoding = params.get(‘charset’, ”).replace(“‘”, “”) if not isinstance(http_encoding, str): http_encoding = http_encoding.decode(‘utf-8’, ‘ignore’) acceptable_content_type = 0 application_content_types = (‘application/xml’, ‘application/xml-dtd’, ‘application/xml-external-parsed-entity’) text_content_types = (‘text/xml’, ‘text/xml-external-parsed-entity’) if (http_content_type in application_content_types) or \ (http_content_type.startswith(‘application/’) and http_content_type.endswith(‘+xml’)): acceptable_content_type = 1 rfc3023_encoding = http_encoding or xml_encoding or ‘utf-8’ elif (http_content_type in text_content_types) or \ (http_content_type.startswith(‘text/’) and http_content_type.endswith(‘+xml’)): acceptable_content_type = 1 rfc3023_encoding = http_encoding or ‘us-ascii’ elif http_content_type.startswith(‘text/’): rfc3023_encoding = http_encoding or ‘us-ascii’ elif http_headers and ‘content-type’ not in http_headers: rfc3023_encoding = xml_encoding or ‘iso-8859-1’ else: rfc3023_encoding = xml_encoding or ‘utf-8’ # gb18030 is a superset of gb2312, so always replace gb2312 # with gb18030 for greater compatibility. if rfc3023_encoding.lower() == ‘gb2312’: rfc3023_encoding = ‘gb18030’ if xml_encoding.lower() == ‘gb2312’: xml_encoding = ‘gb18030’ # there are four encodings to keep track of: # – http_encoding is the encoding declared in the Content-Type HTTP header # – xml_encoding is the encoding declared in the <?xml declaration # – bom_encoding is the encoding sniffed from the first 4 bytes of the XML data # – rfc3023_encoding is the actual encoding, as per RFC 3023 and a variety of other conflicting specifications error = None if http_headers and (not acceptable_content_type): if ‘content-type’ in http_headers: msg = ‘%s is not an XML media type’ % http_headers[‘content-type’] else: msg = ‘no Content-type specified’ error = NonXMLContentType(msg) # determine character encoding known_encoding = 0 lazy_chardet_encoding = None tried_encodings = [] if chardet: def lazy_chardet_encoding(): chardet_encoding = chardet.detect(data)[‘encoding’] if not chardet_encoding: chardet_encoding = ” if not isinstance(chardet_encoding, str): chardet_encoding = str(chardet_encoding, ‘ascii’, ‘ignore’) return chardet_encoding # try: HTTP encoding, declared XML encoding, encoding sniffed from BOM for proposed_encoding in (rfc3023_encoding, xml_encoding, bom_encoding, lazy_chardet_encoding, ‘utf-8’, ‘windows-1252’, ‘iso-8859-2′): if isinstance(proposed_encoding, collections.Callable): proposed_encoding = proposed_encoding() if not proposed_encoding: continue if proposed_encoding in tried_encodings: continue tried_encodings.append(proposed_encoding) try: data = data.decode(proposed_encoding) except (UnicodeDecodeError, LookupError): pass else: known_encoding = 1 # Update the encoding in the opening XML processing instruction. new_declaration = ”'<?xml version=’1.0′ encoding=’utf-8′?>”’ if RE_XML_DECLARATION.search(data): data = RE_XML_DECLARATION.sub(new_declaration, data) else: data = new_declaration + ‘\n’ + data data = data.encode(‘utf-8’) break # if still no luck, give up if not known_encoding: error = CharacterEncodingUnknown( ‘document encoding unknown, I tried ‘ + ‘%s, %s, utf-8, windows-1252, and iso-8859-2 but nothing worked’ % (rfc3023_encoding, xml_encoding)) rfc3023_encoding = ” elif proposed_encoding != rfc3023_encoding: error = CharacterEncodingOverride( ‘document declared as %s, but parsed as %s’ % (rfc3023_encoding, proposed_encoding)) rfc3023_encoding = proposed_encoding return data, rfc3023_encoding, error # Match XML entity declarations. # Example: <!ENTITY copyright “(C)”> RE_ENTITY_PATTERN = re.compile(_s2bytes(r’^\s*<!ENTITY([^>]*?)>’), re.MULTILINE) # Match XML DOCTYPE declarations. # Example: <!DOCTYPE feed [ ]> RE_DOCTYPE_PATTERN = re.compile(_s2bytes(r’^\s*<!DOCTYPE([^>]*?)>’), re.MULTILINE) # Match safe entity declarations. # This will allow hexadecimal character references through, # as well as text, but not arbitrary nested entities. # Example: cubed “³” # Example: copyright “(C)” # Forbidden: explode1 “&explode2;&explode2;” RE_SAFE_ENTITY_PATTERN = re.compile(_s2bytes(‘\s+(\w+)\s+”(&#\w+;|[^&”]*)”‘)) def replace_doctype(data): ”’Strips and replaces the DOCTYPE, returns (rss_version, stripped_data) rss_version may be ‘rss091n’ or None stripped_data is the same XML document with a replaced DOCTYPE ”’ # Divide the document into two groups by finding the location # of the first element that doesn’t begin with ‘<?’ or ‘<!’. start = re.search(_s2bytes(‘<\w’), data) start = start and start.start() or -1 head, data = data[:start+1], data[start+1:] # Save and then remove all of the ENTITY declarations. entity_results = RE_ENTITY_PATTERN.findall(head) head = RE_ENTITY_PATTERN.sub(_s2bytes(”), head) # Find the DOCTYPE declaration and check the feed type. doctype_results = RE_DOCTYPE_PATTERN.findall(head) doctype = doctype_results and doctype_results[0] or _s2bytes(”) if _s2bytes(‘netscape’) in doctype.lower(): version = ‘rss091n’ else: version = None # Re-insert the safe ENTITY declarations if a DOCTYPE was found. replacement = _s2bytes(”) if len(doctype_results) == 1 and entity_results: match_safe_entities = lambda e: RE_SAFE_ENTITY_PATTERN.match(e) safe_entities = list(filter(match_safe_entities, entity_results)) if safe_entities: replacement = _s2bytes(‘<!DOCTYPE feed [\n<!ENTITY’) \ + _s2bytes(‘>\n<!ENTITY ‘).join(safe_entities) \ + _s2bytes(‘>\n]>’) data = RE_DOCTYPE_PATTERN.sub(replacement, head) + data # Precompute the safe entities for the loose parser. safe_entities = dict((k.decode(‘utf-8’), v.decode(‘utf-8’)) for k, v in RE_SAFE_ENTITY_PATTERN.findall(replacement)) return version, data, safe_entities # GeoRSS geometry parsers. Each return a dict with ‘type’ and ‘coordinates’ # items, or None in the case of a parsing error. def _parse_poslist(value, geom_type, swap=True, dims=2): if geom_type == ‘linestring’: return _parse_georss_line(value, swap, dims) elif geom_type == ‘polygon’: ring = _parse_georss_line(value, swap, dims) return {‘type’: ‘Polygon’, ‘coordinates’: (ring[‘coordinates’],)} else: return None def _gen_georss_coords(value, swap=True, dims=2): # A generator of (lon, lat) pairs from a string of encoded GeoRSS # coordinates. Converts to floats and swaps order. latlons = map(float, value.strip().replace(‘,’, ‘ ‘).split()) nxt = latlons.__next__ while True: t = [nxt(), nxt()][::swap and -1 or 1] if dims == 3: t.append(nxt()) yield tuple(t) def _parse_georss_point(value, swap=True, dims=2): # A point contains a single latitude-longitude pair, separated by # whitespace. We’ll also handle comma separators. try: coords = list(_gen_georss_coords(value, swap, dims)) return {‘type’: ‘Point’, ‘coordinates’: coords[0]} except (IndexError, ValueError): return None def _parse_georss_line(value, swap=True, dims=2): # A line contains a space separated list of latitude-longitude pairs in # WGS84 coordinate reference system, with each pair separated by # whitespace. There must be at least two pairs. try: coords = list(_gen_georss_coords(value, swap, dims)) return {‘type’: ‘LineString’, ‘coordinates’: coords} except (IndexError, ValueError): return None def _parse_georss_polygon(value, swap=True, dims=2): # A polygon contains a space separated list of latitude-longitude pairs, # with each pair separated by whitespace. There must be at least four # pairs, with the last being identical to the first (so a polygon has a # minimum of three actual points). try: ring = list(_gen_georss_coords(value, swap, dims)) except (IndexError, ValueError): return None if len(ring) < 4: return None return {‘type’: ‘Polygon’, ‘coordinates’: (ring,)} def _parse_georss_box(value, swap=True, dims=2): # A bounding box is a rectangular region, often used to define the extents # of a map or a rough area of interest. A box contains two space seperate # latitude-longitude pairs, with each pair separated by whitespace. The # first pair is the lower corner, the second is the upper corner. try: coords = list(_gen_georss_coords(value, swap, dims)) return {‘type’: ‘Box’, ‘coordinates’: tuple(coords)} except (IndexError, ValueError): return None # end geospatial parsers def parse(url_file_stream_or_string, etag=None, modified=None, agent=None, referrer=None, handlers=None, request_headers=None, response_headers=None): ”’Parse a feed from a URL, file, stream, or string. request_headers, if given, is a dict from http header name to value to add to the request; this overrides internally generated values. :return: A :class:`FeedParserDict`. ”’ if handlers is None: handlers = [] if request_headers is None: request_headers = {} if response_headers is None: response_headers = {} result = FeedParserDict() result[‘feed’] = FeedParserDict() result[‘entries’] = [] result[‘bozo’] = 0 if not isinstance(handlers, list): handlers = [handlers] try: f = _open_resource(url_file_stream_or_string, etag, modified, agent, referrer, handlers, request_headers) data = f.read() except Exception as e: result[‘bozo’] = 1 result[‘bozo_exception’] = e data = None f = None if hasattr(f, ‘headers’): result[‘headers’] = dict(f.headers) # overwrite existing headers using response_headers if ‘headers’ in result: result[‘headers’].update(response_headers) elif response_headers: result[‘headers’] = copy.deepcopy(response_headers) # lowercase all of the HTTP headers for comparisons per RFC 2616 if ‘headers’ in result: http_headers = dict((k.lower(), v) for k, v in list(result[‘headers’].items())) else: http_headers = {} # if feed is gzip-compressed, decompress it if f and data and http_headers: if gzip and ‘gzip’ in http_headers.get(‘content-encoding’, ”): try: data = gzip.GzipFile(fileobj=_StringIO(data)).read() except (IOError, struct.error) as e: # IOError can occur if the gzip header is bad. # struct.error can occur if the data is damaged. result[‘bozo’] = 1 result[‘bozo_exception’] = e if isinstance(e, struct.error): # A gzip header was found but the data is corrupt. # Ideally, we should re-request the feed without the # ‘Accept-encoding: gzip’ header, but we don’t. data = None elif zlib and ‘deflate’ in http_headers.get(‘content-encoding’, ”): try: data = zlib.decompress(data) except zlib.error as e: try: # The data may have no headers and no checksum. data = zlib.decompress(data, -15) except zlib.error as e: result[‘bozo’] = 1 result[‘bozo_exception’] = e # save HTTP headers if http_headers: if ‘etag’ in http_headers: etag = http_headers.get(‘etag’, ”) if not isinstance(etag, str): etag = etag.decode(‘utf-8’, ‘ignore’) if etag: result[‘etag’] = etag if ‘last-modified’ in http_headers: modified = http_headers.get(‘last-modified’, ”) if modified: result[‘modified’] = modified result[‘modified_parsed’] = _parse_date(modified) if hasattr(f, ‘url’): if not isinstance(f.url, str): result[‘href’] = f.url.decode(‘utf-8’, ‘ignore’) else: result[‘href’] = f.url result[‘status’] = 200 if hasattr(f, ‘status’): result[‘status’] = f.status if hasattr(f, ‘close’): f.close() if data is None: return result # Stop processing if the server sent HTTP 304 Not Modified. if getattr(f, ‘code’, 0) == 304: result[‘version’] = ” result[‘debug_message’] = ‘The feed has not changed since you last checked, ‘ + \ ‘so the server sent no data. This is a feature, not a bug!’ return result data, result[‘encoding’], error = convert_to_utf8(http_headers, data) use_strict_parser = result[‘encoding’] and True or False if error is not None: result[‘bozo’] = 1 result[‘bozo_exception’] = error result[‘version’], data, entities = replace_doctype(data) # Ensure that baseuri is an absolute URI using an acceptable URI scheme. contentloc = http_headers.get(‘content-location’, ”) href = result.get(‘href’, ”) baseuri = _makeSafeAbsoluteURI(href, contentloc) or _makeSafeAbsoluteURI(contentloc) or href baselang = http_headers.get(‘content-language’, None) if not isinstance(baselang, str) and baselang is not None: baselang = baselang.decode(‘utf-8’, ‘ignore’) if not _XML_AVAILABLE: use_strict_parser = 0 if use_strict_parser: # initialize the SAX parser feedparser = _StrictFeedParser(baseuri, baselang, ‘utf-8’) saxparser = xml.sax.make_parser(PREFERRED_XML_PARSERS) saxparser.setFeature(xml.sax.handler.feature_namespaces, 1) try: # disable downloading external doctype references, if possible saxparser.setFeature(xml.sax.handler.feature_external_ges, 0) except xml.sax.SAXNotSupportedException: pass saxparser.setContentHandler(feedparser) saxparser.setErrorHandler(feedparser) source = xml.sax.xmlreader.InputSource() source.setByteStream(_StringIO(data)) try: saxparser.parse(source) except xml.sax.SAXException as e: result[‘bozo’] = 1 result[‘bozo_exception’] = feedparser.exc or e use_strict_parser = 0 if not use_strict_parser and _SGML_AVAILABLE: feedparser = _LooseFeedParser(baseuri, baselang, ‘utf-8’, entities) feedparser.feed(data.decode(‘utf-8’, ‘replace’)) result[‘feed’] = feedparser.feeddata result[‘entries’] = feedparser.entries result[‘version’] = result[‘version’] or feedparser.version result[‘namespaces’] = feedparser.namespacesInUse return result # The list of EPSG codes for geographic (latitude/longitude) coordinate # systems to support decoding of GeoRSS GML profiles. _geogCS = [ 3819, 3821, 3824, 3889, 3906, 4001, 4002, 4003, 4004, 4005, 4006, 4007, 4008, 4009, 4010, 4011, 4012, 4013, 4014, 4015, 4016, 4018, 4019, 4020, 4021, 4022, 4023, 4024, 4025, 4027, 4028, 4029, 4030, 4031, 4032, 4033, 4034, 4035, 4036, 4041, 4042, 4043, 4044, 4045, 4046, 4047, 4052, 4053, 4054, 4055, 4075, 4081, 4120, 4121, 4122, 4123, 4124, 4125, 4126, 4127, 4128, 4129, 4130, 4131, 4132, 4133, 4134, 4135, 4136, 4137, 4138, 4139, 4140, 4141, 4142, 4143, 4144, 4145, 4146, 4147, 4148, 4149, 4150, 4151, 4152, 4153, 4154, 4155, 4156, 4157, 4158, 4159, 4160, 4161, 4162, 4163, 4164, 4165, 4166, 4167, 4168, 4169, 4170, 4171, 4172, 4173, 4174, 4175, 4176, 4178, 4179, 4180, 4181, 4182, 4183, 4184, 4185, 4188, 4189, 4190, 4191, 4192, 4193, 4194, 4195, 4196, 4197, 4198, 4199, 4200, 4201, 4202, 4203, 4204, 4205, 4206, 4207, 4208, 4209, 4210, 4211, 4212, 4213, 4214, 4215, 4216, 4218, 4219, 4220, 4221, 4222, 4223, 4224, 4225, 4226, 4227, 4228, 4229, 4230, 4231, 4232, 4233, 4234, 4235, 4236, 4237, 4238, 4239, 4240, 4241, 4242, 4243, 4244, 4245, 4246, 4247, 4248, 4249, 4250, 4251, 4252, 4253, 4254, 4255, 4256, 4257, 4258, 4259, 4260, 4261, 4262, 4263, 4264, 4265, 4266, 4267, 4268, 4269, 4270, 4271, 4272, 4273, 4274, 4275, 4276, 4277, 4278, 4279, 4280, 4281, 4282, 4283, 4284, 4285, 4286, 4287, 4288, 4289, 4291, 4292, 4293, 4294, 4295, 4296, 4297, 4298, 4299, 4300, 4301, 4302, 4303, 4304, 4306, 4307, 4308, 4309, 4310, 4311, 4312, 4313, 4314, 4315, 4316, 4317, 4318, 4319, 4322, 4324, 4326, 4463, 4470, 4475, 4483, 4490, 4555, 4558, 4600, 4601, 4602, 4603, 4604, 4605, 4606, 4607, 4608, 4609, 4610, 4611, 4612, 4613, 4614, 4615, 4616, 4617, 4618, 4619, 4620, 4621, 4622, 4623, 4624, 4625, 4626, 4627, 4628, 4629, 4630, 4631, 4632, 4633, 4634, 4635, 4636, 4637, 4638, 4639, 4640, 4641, 4642, 4643, 4644, 4645, 4646, 4657, 4658, 4659, 4660, 4661, 4662, 4663, 4664, 4665, 4666, 4667, 4668, 4669, 4670, 4671, 4672, 4673, 4674, 4675, 4676, 4677, 4678, 4679, 4680, 4681, 4682, 4683, 4684, 4685, 4686, 4687, 4688, 4689, 4690, 4691, 4692, 4693, 4694, 4695, 4696, 4697, 4698, 4699, 4700, 4701, 4702, 4703, 4704, 4705, 4706, 4707, 4708, 4709, 4710, 4711, 4712, 4713, 4714, 4715, 4716, 4717, 4718, 4719, 4720, 4721, 4722, 4723, 4724, 4725, 4726, 4727, 4728, 4729, 4730, 4731, 4732, 4733, 4734, 4735, 4736, 4737, 4738, 4739, 4740, 4741, 4742, 4743, 4744, 4745, 4746, 4747, 4748, 4749, 4750, 4751, 4752, 4753, 4754, 4755, 4756, 4757, 4758, 4759, 4760, 4761, 4762, 4763, 4764, 4765, 4801, 4802, 4803, 4804, 4805, 4806, 4807, 4808, 4809, 4810, 4811, 4813, 4814, 4815, 4816, 4817, 4818, 4819, 4820, 4821, 4823, 4824, 4901, 4902, 4903, 4904, 4979 ]

pset5/MIT6_0001F16_ps5.pdf

 

Problem Set 5 Handed out: Wednesday, October 12, 2016.

Due: 11:59pm, Wednesday, October 19, 2016.

Introduction You will use object-oriented programming (classes and inheritance) to build a program to monitor news feeds over the Internet. Your program will filter the news, alerting the user when it notices a news story that matches that user’s interests (for example, the user may be interested in a notification whenever a story related to the Red Sox is posted).

This problem set does not require many lines of code! ​ ​ We recommend that the solutions you write for each problem stay under about 15-20 lines of code (the solutions for some

​problems will be ​ much shorter than that). If you find yourself writing way more code than that, you should come visit us at office hours to see how you can simplify things.

Here is the ​official Python tutorial ​ on classes, sections 9.1-9.7 (except for 9.5.1) will be useful for this pset. Chapter 8 in the textbook is also useful.

Getting Started Download and save

pset5.zip: A zip file of all the files you need, including:

● ps5.py, a skeleton for you to fill in ● ps5_test.py, a test suite that will help you check your answers ● triggers.txt, a trigger configuration file ● feedparser.py, a module that will retrieve and parse feeds for you

​ ​

 

 

feed, using an ​RSS feed reader​ instead of a web browser. An RSS reader (e.g. ​Sage​) will periodically collect and draw your attention to updated content.

​ RSS stands for “​Really Simple Syndication.” An RSS feed consists of (periodically changing) data stored in an XML-format file residing on a web-server. For this problem set, the details are unimportant. You don’t need to know what XML is, nor do you need to know how to access these files over the network. We have taken care of retrieving and parsing the XML file for you.

Data Structure Design RSS Feed Structure: Google News

First, let’s talk about one specific RSS feed: Google News. The URL for the Google News feed is: ​http://news.google.com/?output=rss

If you try to load this URL in your browser, you’ll probably see your browser’s interpretation of the XML code generated by the feed. You can view the XML source with your browser’s “View Page Source” function, though it probably will not make much sense to you. Abstractly, whenever you connect to the Google News RSS feed, you receive a ​list of items​. Each ​entry in this list represents a single news ​item​. In a Google News feed, every entry has the following fields:

● guid ​ : A globally unique identifier for this news story. ● title ​ : The news story’s headline. ● description ​ : A paragraph or so summarizing the news story. ● link ​ : A link to a website with the entire story. ● pubDate ​: Date the news was published ● category ​: News category, such as “Top Stories”

Generalizing the Problem

This is a little trickier than we’d like it to be, because each of these RSS feeds is structured a little bit differently than the others. So, our goal is to come up with a unified, standard representation that we’ll use to store a news story.

We want to do this because we want an application that aggregates several RSS feeds from various sources and can act on all of them in the exact same way. We should be able to read news stories from various RSS feeds all in one place.

✦ ✦ ✦ ✦

Problem 1

​ Parsing (see below for a definition) all of this information from the feeds that Google/Yahoo/etc. gives us is no small feat. So, let’s tackle an easy part of the problem first. Pretend that someone has already done the specific parsing, and has left you with variables that contain the following information for a news story:

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● globally unique identifier (GUID) – a string ● title – a string ● description – a string ● link to more content – a string ● pubdate – a ​datetime

​ We want to store this information in an ​object that we can then pass around in the rest of our program. Your task, in this problem, is to write a class, ​NewsStory ​, ​starting with a constructor​ that takes (​guid, title, description, link, pubdate ​) as arguments and stores them appropriately. ​NewsStory ​ also needs to contain the following methods:

● get_guid(self) ● get_title(self) ● get_description(self) ● get_link(self) ● get_pubdate(self)

The solution to this problem should be relatively short and very straightforward (please review what get methods should do if you find yourself writing multiple lines of code for each). Once you have implemented ​NewsStory ​ all the ​NewsStory ​ test cases should work.

✦ ✦ ✦ ✦

Parsing the Feed

Parsing is the process of turning a data stream into a structured format that is more convenient to work with. We have provided you with code that will retrieve and parse the Google and Yahoo news feeds.

Triggers Given a set of news stories, your program will generate ​alerts​ for a subset of those stories. Stories with alerts will be displayed to the user, and the other stories will be silently discarded. We will represent alerting rules as ​triggers​. A trigger is a rule that is evaluated over a single news story and may fire to generate an alert. For example, a simple trigger could fire for every news story whose title contained the phrase “Microsoft Office”. Another trigger may be set up to fire for all news stories where the description contained the phrase “Boston”. Finally, a more specific trigger could be set up to fire only when a news story contained both the phrases “Microsoft Office” and “Boston” in the description.

In order to simplify our code, we will use object polymorphism. We will define a trigger interface and then implement a number of different classes that implement that trigger interface in different ways.

Trigger Interface

Each trigger class you define should implement the following interface, either directly or transitively. It must implement the ​evaluate​ method that takes a news item (​NewsStory ​ object) as an input and returns ​True ​ if an alert should be generated for that item. We will not directly

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use the implementation of the ​Trigger ​ class, which is why it raises an exception should anyone attempt to use it.

The class below implements the Trigger interface (you will not modify this). Any subclass that inherits from it will have an evaluate method. By default, they will use the evaluate method in Trigger , the superclass, unless they define their own evaluate function, which would then be used instead. If some subclass neglects to define its own ​evaluate() ​ method, calls to it will go to Trigger.evaluate() , which fails (albeit cleanly) with the NotImplementedError :

class Trigger(object): def evaluate(self, story):

“”” Returns True if an alert should be generated for the given news item, or False otherwise. “”” raise NotImplementedError

We will define a number of classes that inherit from Trigger . In the figure below, Trigger is a superclass, from which all other classes inherit. The arrow from ​PhraseTrigger ​ to Trigger means that PhraseTrigger inherits from Trigger – a PhraseTrigger is a Trigger . Note that other classes inherit from ​PhraseTrigger ​.

Phrase Triggers

Having a trigger that always fires isn’t interesting; let’s write some that are interesting! A user may want to be alerted about news items that contain specific phrases. For instance, a simple

​ trigger could fire for every news item whose ​title contains the phrase “Microsoft Office”. In the​ following problems, you will create a phrase trigger ​abstract class and implement two classes

that implement this phrase trigger.

A ​phrase​ is one or more words separated by a single space between the words. You may

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assume that a phrase does not contain any punctuation. Here are some examples of valid phrases:

● ‘purple cow’ ● ‘PURPLE COW’ ● ‘mOoOoOoO’ ● ‘this is a phrase’

But these are ​NOT​ valid phrases: ● ‘purple cow???’ ​ (contains punctuation) ● ‘purple cow’ ​ (contains multiple spaces between words)

Given some text, the trigger should fire only when each word in the phrase is present in its entirety and appears consecutively in the text, separated only by spaces or punctuation. The trigger should not be case sensitive. For example, a phrase trigger with the phrase “purple cow” should fire on the following text snippets:

● ‘PURPLE COW’ ● ‘The purple cow is soft and cuddly.’ ● ‘The farmer owns a really PURPLE cow.’ ● ‘Purple!!! Cow!!!’ ● ‘purple@#$%cow’ ● ‘Did you see a purple cow?’

But it should not fire on these text snippets: ● ‘Purple cows are cool!’ ● ‘The purple blob over there is a cow.’ ● ‘How now brown cow.’ ● ‘Cow!!! Purple!!!’ ● ‘purplecowpurplecowpurplecow’

Dealing with exclamation marks and other punctuation that appear in the middle of the phrase is a little tricky. For the purpose of your parsing, pretend that a space or any character in string.punctuation ​ is a word separator. If you’ve never seen ​string.punctuation before, go to the Python shell and type: >>> import string >>> print string.punctuation

Play around with this a bit to get comfortable with what it is. The ​split ​, ​replace ​, ​join ​, methods of strings will almost certainly be helpful as you tackle this part.

You may also find the string methods ​lower ​ and/or ​upper ​ useful for this problem.

✦ ✦ ✦ ✦

Problem 2

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Implement a phrase trigger abstract class, ​PhraseTrigger ​. It should take in a string phrase as an argument to the class’s constructor. This trigger should not be case-sensitive (it should treat ​”Intel” ​ and ​”intel” ​ as being equal).

PhraseTrigger ​ should be a subclass of ​Trigger ​. It has one new method, is_phrase_in ​, which takes in one string argument text. It returns ​True ​ if the whole phrase phrase ​ is present in text, ​False ​ otherwise, as described in the above examples. This method should not be case-sensitive. Implement this method.

Because this is an abstract class, we will not be directly instantiating any ​PhraseTriggers ​. PhraseTrigger ​ should inherit its evaluate method from ​Trigger ​. We do this because now we can create subclasses of ​PhraseTrigger ​ that use its ​is_phrase_in ​ function.

✦ ✦ ✦ ✦

You are now ready to implement ​PhraseTrigger ​’s two subclasses: ​TitleTrigger ​ and DescriptionTrigger ​.

✦ ✦ ✦ ✦

Problem 3

Implement a phrase trigger subclass, ​TitleTrigger ​ that fires when a news item’s ​title contains a given phrase. For example, an instance of this type of trigger could be used to generate an alert whenever the phrase ​”Intel processors” ​ occurred in the title of a news item.

As it was in ​PhaseTrigger ​, the phrase should be an argument to the class’s constructor, and the trigger should not be case-sensitive.

Think carefully about what methods should be defined in ​TitleTrigger​ and what methods should be inherited from the superclass. ​Once you’ve implemented TitleTrigger ​, the ​TitleTrigger ​ unit tests in our test suite should pass. Remember that all subclasses that inherit from the ​Trigger ​ interface should include a working ​evaluate method.

If you find that you’re not passing the unit tests, keep in mind that FAIL means your code runs but produces the wrong answer, whereas ERROR means that your code crashes due to some error.

✦ ✦ ✦ ✦

Problem 4

Implement a phrase trigger subclass, ​DescriptionTrigger ​, that fires when a news item’s description​ contains a given phrase. As it was in ​PhaseTrigger ​, the phrase should be an argument to the class’s constructor, and the trigger should not be case-sensitive.

Once you’ve implemented ​DescriptionTrigger ​, the ​DescriptionTrigger ​ unit tests in our test suite should pass.

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✦ ✦ ✦ ✦

Time Triggers

Let’s move on from ​PhraseTrigger. ​Now we want to have triggers that is based on when the ​NewsStory ​was published, not on its news content. Please check the earlier diagram if you’re confused about the inheritance structure of the Triggers in this problem set.

Problem 5

Implement a time trigger abstract class, ​TimeTrigger ​, that is a subclass of ​Trigger ​. The​ class’s constructor should take in time in EST as a ​string in the format of “3 Oct 2016

17:00:10 “. ​Make sure to convert time from string to a datetime before saving it as an attribute.​ Some of ​datetime ​’s methods, ​strptime ​ and ​replace ​, ​ along with an explanation of the string format for time​, might come in handy. You can also look at the provided code in ​process ​ to check. You do not have to implement any other methods.

Because this is an abstract class, we will not be directly instantiating any ​TimeTrigger ​.

✦ ✦ ✦ ✦

Problem 6

Implement ​BeforeTrigger ​ and ​AfterTrigger ​, two subclasses of ​TimeTrigger ​. BeforeTrigger ​fires when a story is published strictly before the trigger’s time, and AfterTrigger ​fires when a story is published strictly after the trigger’s time. Their evaluate ​ should not take more than a couple of lines of code.

Once you’ve implemented ​BeforeTrigger ​and ​AfterTrigger ​, the BeforeAndAfterTrigger ​unit tests in our test suite should pass.

✦ ✦ ✦ ✦

Composite Triggers

So the triggers above are mildly interesting, but we want to do better: we want to ‘compose’ the earlier triggers to set up more powerful alert rules. For instance, we may want to raise an alert only when both ​”google glass” ​ and ​”stock” ​ were present in the news item (an idea we can’t express with just phrase triggers).

​ Note that these triggers are ​not phrase triggers and should not be subclasses of PhraseTrigger ​. Again, please refer back to the earlier diagram if you’re confused about the inheritance structure of Trigger.

✦ ✦ ✦ ✦

Problem 7

Implement a NOT trigger (​NotTrigger ​).

This trigger should produce its output by inverting the output of another trigger. The NOT

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trigger should take this other trigger as an argument to its constructor (why its constructor? Because we can’t change what parameters evaluate takes in…that’d break our polymorphism). So, given a trigger ​T ​ and a news item ​x ​, the output of the NOT trigger’s evaluate method should be equivalent to ​not T.evaluate(x) ​.

When this is done, the ​NotTrigger ​ unit tests should pass.

✦ ✦ ✦ ✦

Problem 8

Implement an AND trigger (​AndTrigger ​).

This trigger should take two triggers as arguments to its constructor, and should fire on a​ news story only if ​both of the inputted triggers would fire on that item.

When this is done, the ​AndTrigger ​ unit tests should pass.

✦ ✦ ✦ ✦

Problem 9

Implement an OR trigger (​OrTrigger ​).

This trigger should take two triggers as arguments to its constructor, and should fire if either one (or both) of its inputted triggers would fire on that item.

When this is done, the ​OrTrigger ​ unit tests should pass.

✦ ✦ ✦ ✦

Filtering At this point, you can run ps5.py, and it will fetch and display Google and Yahoo news items for

​ in a pop-up window. How many news items? ​All of them.

Right now, the code we’ve given you in ps5.py gets the news from both feeds every minute and displays the result. This is nice, but, remember, the goal here was to filter out only the the stories we wanted.

✦ ✦ ✦ ✦

Problem 10

Write a function, ​filter_stories(stories, triggerlis t) ​ that takes in a list of news stories and a list of triggers, and returns a list of only the stories for which a trigger fires.

After completing Problem 10, you can try running ps5.py, and various RSS news items should pop up, filtered by some hard-coded triggers defined for you in code near the bottom. You may need to change these triggers to reflect what is currently in the news. The code runs an infinite loop, checking the RSS feeds for new stories every 120 seconds.

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✦ ✦ ✦ ✦

User-Specified Triggers Right now, your triggers are specified in your Python code, and to change them, you have to edit your program. This is very user-unfriendly. (Imagine if you had to edit the source code of your web browser every time you wanted to add a bookmark!)

Instead, we want you to read your trigger configuration from a ​triggers.txt ​ file every time your application starts and use the triggers specified there.

Consider the following example configuration file:

// description trigger named t1 t1,DESCRIPTION,Presidential Election

// title trigger named t2 t2,TITLE,Hillary Clinton

// description trigger named t3 t3,DESCRIPTION,Donald Trump

// composite trigger named t4 t4,AND,t2,t3

// the trigger list contains t1 and t4 ADD,t1,t4

The example file specifies that four triggers should be created, and that two of those triggers should be added to the trigger list:

● A trigger that fires when the description contains the phrase ​’Presidential Election’ ​ (​t1 ​).

● A trigger that fires when the title contains the description ​Donald Trump ​ and the title contains the phrase ​Hillary Clinton ​(​t4 ​).

The two other triggers (​t2 ​ and ​t3 ​) are created but not added to the trigger list directly. They are used as arguments for the composite AND trigger’s definition (​t4 ​).

Each line in this file does one of the following:

● is blank ● is a comment (begins with ​// ​ with no spaces preceding the ​// ​) ● defines a named trigger ● adds triggers to the trigger list

Each type of line is described below.

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Blank:​ blank lines are ignored. A line that consists only of whitespace is a blank line.

Comments:​ Any line that begins with ​// ​ is ignored.

Trigger definitions:​ Lines that do not begin with the keyword ADD define named triggers. Elements in these lines are separated by ​commas​. The first element in a trigger definition is either the keyword ADD or the name of the trigger. The name can be any combination of letters/numbers, but it cannot be the word “ADD”. The second element of a trigger definition is a keyword (e.g., TITLE, AND, etc.) that specifies the type of trigger being defined. The remaining elements of the definition are the trigger arguments. What arguments are required depends on the trigger type:

● TITLE​: one phrase ● DESCRIPTION​: one phrase ● AFTER​: one correctly formatted time string ● BEFORE​: one correctly formatted time string ● NOT​: the name of the trigger that will be NOT’d ● AND​: the names of the two triggers that will be AND’d. ● OR​: the names of the two triggers that will be OR’d.

Trigger addition:​ A trigger definition should create a trigger and associate it with a name but should NOT automatically add that trigger to the trigger list. One or more ADD lines in the trigger configuration file will specify which triggers should be in the trigger list. An ADD line begins with the ADD keyword. The elements following ADD are the names of one or more previously defined triggers. The elements in these lines are also separated by commas. These triggers will be added to the the trigger list.

✦ ✦ ✦ ✦

Problem 11

Finish implementing ​read_trigger_config(filename) ​. We’ve written code to open the file and throw away all blank lines and comments. Your job is to finish the implementation. read_trigger_config ​ should return a list of triggers specified by the configuration file.

Hint:​ Feel free to define a helper function if you wish! Using a helper function is ​not​ required though.

Hint:​ You will probably find it helpful to use a dictionary where the keys are trigger names.

Once that’s done, modify the code within the function main_thread to use the trigger list specified in your configuration file, instead of the one we hard-coded for you:

# TODO: Problem 11 # After implementing read_trigger_config, uncomment this line: # triggerlist = read_trigger_config(‘triggers.txt’)

After completing Problem 11, you can try running ​ps5.py ​, and depending on your triggers.txt ​ file, various RSS news items should pop up. The code runs an infinite loop, checking the RSS feed for new stories every 120 seconds.

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Hint:​ If no stories are popping up, open up ​triggers.txt ​ and change the triggers to ones that reflect current events (if you don’t keep up with the news, just pick some triggers that would fire on the current ​Google News​ stories).

Problem 12

Think about ​the presidential debate coming up on October 19th​, and write debate_triggers.txt ​so that you can get news that is published within the +/- 3 hour window of the debate!

✦ ✦ ✦ ✦

This completes the problem set!

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MIT OpenCourseWare https://ocw.mit.edu

6.0001 Introduction to Computer Science and Programming in Python Fall 2016

For information about citing these materials or our Terms of Use, visit: https://ocw.mit.edu/terms.

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pset5/mtTkinter.py

”’Thread-safe version of Tkinter. Copyright (c) 2009, Allen B. Taylor This module is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser Public License for more details. You should have received a copy of the GNU Lesser Public License along with this program. If not, see <http://www.gnu.org/licenses/>. Usage: import mtTkinter as Tkinter # Use “Tkinter.” as usual. or from mtTkinter import * # Use Tkinter module definitions as usual. This module modifies the original Tkinter module in memory, making all functionality thread-safe. It does this by wrapping the Tk class’ tk instance with an object that diverts calls through an event queue when the call is issued from a thread other than the thread in which the Tk instance was created. The events are processed in the creation thread via an ‘after’ event. The modified Tk class accepts two additional keyword parameters on its __init__ method: mtDebug: 0 = No debug output (default) 1 = Minimal debug output … 9 = Full debug output mtCheckPeriod: Amount of time in milliseconds (default 100) between checks for out-of-thread events when things are otherwise idle. Decreasing this value can improve GUI responsiveness, but at the expense of consuming more CPU cycles. Note that, because it modifies the original Tkinter module (in memory), other modules that use Tkinter (e.g., Pmw) reap the benefits automagically as long as mtTkinter is imported at some point before extra threads are created. Author: Allen B. Taylor, a.b.taylor@gmail.com ”’ from tkinter import * import threading import queue class _Tk(object): “”” Wrapper for underlying attribute tk of class Tk. “”” def __init__(self, tk, mtDebug = 0, mtCheckPeriod = 10): self._tk = tk # Create the incoming event queue. self._eventQueue = queue.Queue(1) # Identify the thread from which this object is being created so we can # tell later whether an event is coming from another thread. self._creationThread = threading.currentThread() # Store remaining values. self._debug = mtDebug self._checkPeriod = mtCheckPeriod def __getattr__(self, name): # Divert attribute accesses to a wrapper around the underlying tk # object. return _TkAttr(self, getattr(self._tk, name)) class _TkAttr(object): “”” Thread-safe callable attribute wrapper. “”” def __init__(self, tk, attr): self._tk = tk self._attr = attr def __call__(self, *args, **kwargs): “”” Thread-safe method invocation. Diverts out-of-thread calls through the event queue. Forwards all other method calls to the underlying tk object directly. “”” # Check if we’re in the creation thread. if threading.currentThread() == self._tk._creationThread: # We’re in the creation thread; just call the event directly. if self._tk._debug >= 8 or \ self._tk._debug >= 3 and self._attr.__name__ == ‘call’ and \ len(args) >= 1 and args[0] == ‘after’: print( ‘Calling event directly:’, \ self._attr.__name__, args, kwargs) return self._attr(*args, **kwargs) else: # We’re in a different thread than the creation thread; enqueue # the event, and then wait for the response. responseQueue = queue.Queue(1) if self._tk._debug >= 1: print( ‘Marshalling event:’, self._attr.__name__, args, kwargs) self._tk._eventQueue.put((self._attr, args, kwargs, responseQueue)) isException, response = responseQueue.get() # Handle the response, whether it’s a normal return value or # an exception. if isException: exType, exValue, exTb = response raise exType#, exValue, exTb else: return response # Define a hook for class Tk’s __init__ method. def _Tk__init__(self, *args, **kwargs): # We support some new keyword arguments that the original __init__ method # doesn’t expect, so separate those out before doing anything else. new_kwnames = (‘mtCheckPeriod’, ‘mtDebug’) new_kwargs = {} for name, value in kwargs.items(): if name in new_kwnames: new_kwargs[name] = value del kwargs[name] # Call the original __init__ method, creating the internal tk member. self.__original__init__mtTkinter(*args, **kwargs) # Replace the internal tk member with a wrapper that handles calls from # other threads. self.tk = _Tk(self.tk, **new_kwargs) # Set up the first event to check for out-of-thread events. self.after_idle(_CheckEvents, self) # Replace Tk’s original __init__ with the hook. Tk.__original__init__mtTkinter = Tk.__init__ Tk.__init__ = _Tk__init__ def _CheckEvents(tk): “Event checker event.” used = False try: # Process all enqueued events, then exit. while True: try: # Get an event request from the queue. method, args, kwargs, responseQueue = \ tk.tk._eventQueue.get_nowait() except: # No more events to process. break else: # Call the event with the given arguments, and then return # the result back to the caller via the response queue. used = True if tk.tk._debug >= 2: print( ‘Calling event from main thread:’, \ method.__name__, args, kwargs) try: responseQueue.put((False, method(*args, **kwargs))) except (SystemExit, ex): raise (SystemExit, ex) except (Exception, ex): # Calling the event caused an exception; return the # exception back to the caller so that it can be raised # in the caller’s thread. from sys import exc_info exType, exValue, exTb = exc_info() responseQueue.put((True, (exType, exValue, exTb))) finally: # Schedule to check again. If we just processed an event, check # immediately; if we didn’t, check later. if used: tk.after_idle(_CheckEvents, tk) else: tk.after(tk.tk._checkPeriod, _CheckEvents, tk) # Test thread entry point. def _testThread(root): text = “This is Tcl/Tk version %s” % TclVersion if TclVersion >= 8.1: try: text = text + unicode(“\nThis should be a cedilla: \347”, “iso-8859-1”) except NameError: pass # no unicode support try: if root.globalgetvar(‘tcl_platform(threaded)’): text = text + “\nTcl is built with thread support” else: raise RuntimeError except: text = text + “\nTcl is NOT built with thread support” text = text + “\nmtTkinter works with or without Tcl thread support” label = Label(root, text=text) label.pack() button = Button(root, text=”Click me!”, command=lambda root=root: root.button.configure( text=”[%s]” % root.button[‘text’])) button.pack() root.button = button quit = Button(root, text=”QUIT”, command=root.destroy) quit.pack() # The following three commands are needed so the window pops # up on top on Windows… root.iconify() root.update() root.deiconify() # Simulate button presses… button.invoke() root.after(1000, _pressOk, root, button) # Test button continuous press event. def _pressOk(root, button): button.invoke() try: root.after(1000, _pressOk, root, button) except: pass # Likely we’re exiting # Test. Mostly borrowed from the Tkinter module, but the important bits moved # into a separate thread. if __name__ == ‘__main__’: import threading root = Tk(mtDebug = 1) thread = threading.Thread(target = _testThread, args=(root,)) thread.start() root.mainloop() thread.join()

pset5/project_util.py

# # Utility functions for 6.00 # # A HTML escape code -> text decoding table HTML_ESCAPE_DECODE_TABLE = { “#39” : “\'”, “quot” : “\””, “#34” : “\””, “amp” : “&”, “#38” : “&”, “lt” : “<“, “#60” : “<“, “gt” : “>”, “#62” : “>”, “nbsp” : ” “, “#160″ : ” ” } def translate_html(html_fragment): “”” Translates a HTML fragment to plain text. html_fragment: string (ascii or unicode) returns: string (ascii) “”” txt = “” # translated string parser_reg=”” # parser register parser_state = “TEXT” # parser state: TEXT, ESCAPE or TAG for x in html_fragment: # process each character in html fragment parser_reg += x if parser_state == “TEXT”: # in TEXT mode. if x == ‘<‘: # does this char start a tag? parser_state = “TAG” elif x == ‘&’: # does this char start an escape code? parser_state = “ESCAPE” else: # otherwise, this is normal text txt += x # copy the character as-is to output parser_reg = “” # character handled, erase register elif parser_state == “TAG”: # inside an html TAG. if x == ‘>’: # does this char end the tag? parser_state = “TEXT”# return to TEXT mode for next character tag = parser_reg # the complete tag is in the register # translate some tags, ignore all others if tag[1:-1] == “br” or tag[1:4] == “br “: txt += “\n” elif tag == “</table>”: txt += “\n” elif tag == “<p>”: txt += “\n\n” parser_reg = “” # tag handled, erase register elif parser_state == “ESCAPE”: # inside an ESCAPE code if x == ‘;’: # does this char end an escape code? parser_state = “TEXT” # return to TEXT mode for next character esc = parser_reg[1:-1] # complete escape code is in register if esc in HTML_ESCAPE_DECODE_TABLE: # try to decode escape code txt += HTML_ESCAPE_DECODE_TABLE[esc] else: txt += ” ” # unknown escape code -> space parser_reg = “” # code handled, erase register if type(txt) is str: txt = unicode_to_ascii(txt) return txt def unicode_to_ascii(s): “”” converts s to an ascii string. s: unicode string “”” ret = “” for ch in s: try: ach = str(ch) ret += ach except UnicodeEncodeError: ret += “?” return ret

pset5/ps5.py

# 6.0001/6.00 Problem Set 5 – RSS Feed Filter # Name: # Collaborators: # Time: import feedparser import string import time import threading from project_util import translate_html from mtTkinter import * from datetime import datetime import pytz #———————————————————————– #====================== # Code for retrieving and parsing # Google and Yahoo News feeds # Do not change this code #====================== def process(url): “”” Fetches news items from the rss url and parses them. Returns a list of NewsStory-s. “”” feed = feedparser.parse(url) entries = feed.entries ret = [] for entry in entries: guid = entry.guid title = translate_html(entry.title) link = entry.link description = translate_html(entry.description) pubdate = translate_html(entry.published) try: pubdate = datetime.strptime(pubdate, “%a, %d %b %Y %H:%M:%S %Z”) pubdate.replace(tzinfo=pytz.timezone(“GMT”)) # pubdate = pubdate.astimezone(pytz.timezone(‘EST’)) # pubdate.replace(tzinfo=None) except ValueError: pubdate = datetime.strptime(pubdate, “%a, %d %b %Y %H:%M:%S %z”) newsStory = NewsStory(guid, title, description, link, pubdate) ret.append(newsStory) return ret #====================== # Data structure design #====================== # Problem 1 # TODO: NewsStory #====================== # Triggers #====================== class Trigger(object): def evaluate(self, story): “”” Returns True if an alert should be generated for the given news item, or False otherwise. “”” # DO NOT CHANGE THIS! raise NotImplementedError # PHRASE TRIGGERS # Problem 2 # TODO: PhraseTrigger # Problem 3 # TODO: TitleTrigger # Problem 4 # TODO: DescriptionTrigger # TIME TRIGGERS # Problem 5 # TODO: TimeTrigger # Constructor: # Input: Time has to be in EST and in the format of “%d %b %Y %H:%M:%S”. # Convert time from string to a datetime before saving it as an attribute. # Problem 6 # TODO: BeforeTrigger and AfterTrigger # COMPOSITE TRIGGERS # Problem 7 # TODO: NotTrigger # Problem 8 # TODO: AndTrigger # Problem 9 # TODO: OrTrigger #====================== # Filtering #====================== # Problem 10 def filter_stories(stories, triggerlist): “”” Takes in a list of NewsStory instances. Returns: a list of only the stories for which a trigger in triggerlist fires. “”” # TODO: Problem 10 # This is a placeholder # (we’re just returning all the stories, with no filtering) return stories #====================== # User-Specified Triggers #====================== # Problem 11 def read_trigger_config(filename): “”” filename: the name of a trigger configuration file Returns: a list of trigger objects specified by the trigger configuration file. “”” # We give you the code to read in the file and eliminate blank lines and # comments. You don’t need to know how it works for now! trigger_file = open(filename, ‘r’) lines = [] for line in trigger_file: line = line.rstrip() if not (len(line) == 0 or line.startswith(‘//’)): lines.append(line) # TODO: Problem 11 # line is the list of lines that you need to parse and for which you need # to build triggers print(lines) # for now, print it so you see what it contains! SLEEPTIME = 120 #seconds — how often we poll def main_thread(master): # A sample trigger list – you might need to change the phrases to correspond # to what is currently in the news try: t1 = TitleTrigger(“election”) t2 = DescriptionTrigger(“Trump”) t3 = DescriptionTrigger(“Clinton”) t4 = AndTrigger(t2, t3) triggerlist = [t1, t4] # Problem 11 # TODO: After implementing read_trigger_config, uncomment this line # triggerlist = read_trigger_config(‘triggers.txt’) # HELPER CODE – you don’t need to understand this! # Draws the popup window that displays the filtered stories # Retrieves and filters the stories from the RSS feeds frame = Frame(master) frame.pack(side=BOTTOM) scrollbar = Scrollbar(master) scrollbar.pack(side=RIGHT,fill=Y) t = “Google & Yahoo Top News” title = StringVar() title.set(t) ttl = Label(master, textvariable=title, font=(“Helvetica”, 18)) ttl.pack(side=TOP) cont = Text(master, font=(“Helvetica”,14), yscrollcommand=scrollbar.set) cont.pack(side=BOTTOM) cont.tag_config(“title”, justify=’center’) button = Button(frame, text=”Exit”, command=root.destroy) button.pack(side=BOTTOM) guidShown = [] def get_cont(newstory): if newstory.get_guid() not in guidShown: cont.insert(END, newstory.get_title()+”\n”, “title”) cont.insert(END, “\n—————————————————————\n”, “title”) cont.insert(END, newstory.get_description()) cont.insert(END, “\n*********************************************************************\n”, “title”) guidShown.append(newstory.get_guid()) while True: print(“Polling . . .”, end=’ ‘) # Get stories from Google’s Top Stories RSS news feed stories = process(“http://news.google.com/news?output=rss”) # Get stories from Yahoo’s Top Stories RSS news feed stories.extend(process(“http://news.yahoo.com/rss/topstories”)) stories = filter_stories(stories, triggerlist) list(map(get_cont, stories)) scrollbar.config(command=cont.yview) print(“Sleeping…”) time.sleep(SLEEPTIME) except Exception as e: print(e) if __name__ == ‘__main__’: root = Tk() root.title(“Some RSS parser”) t = threading.Thread(target=main_thread, args=(root,)) t.start() root.mainloop()

pset5/ps5_test.py

# 6.00 # Problem Set 5 Test Suite import unittest from ps5 import * from datetime import timedelta class ProblemSet5NewsStory(unittest.TestCase): def setUp(self): pass def testNewsStoryConstructor(self): story = NewsStory(”, ”, ”, ”, datetime.now()) def testNewsStoryGetGuid(self): story = NewsStory(‘test guid’, ‘test title’, ‘test description’, ‘test link’, datetime.now()) self.assertEqual(story.get_guid(), ‘test guid’) def testNewsStoryGetTitle(self): story = NewsStory(‘test guid’, ‘test title’, ‘test description’, ‘test link’, datetime.now()) self.assertEqual(story.get_title(), ‘test title’) def testNewsStoryGetdescription(self): story = NewsStory(‘test guid’, ‘test title’, ‘test description’, ‘test link’, datetime.now()) self.assertEqual(story.get_description(), ‘test description’) def testNewsStoryGetLink(self): story = NewsStory(‘test guid’, ‘test title’, ‘test description’, ‘test link’, datetime.now()) self.assertEqual(story.get_link(), ‘test link’) def testNewsStoryGetTime(self): story = NewsStory(‘test guid’, ‘test title’, ‘test description’, ‘test link’, datetime.now()) self.assertEqual(type(story.get_pubdate()), datetime) class ProblemSet5(unittest.TestCase): def setUp(self): class TrueTrigger: def evaluate(self, story): return True class FalseTrigger: def evaluate(self, story): return False self.tt = TrueTrigger() self.tt2 = TrueTrigger() self.ft = FalseTrigger() self.ft2 = FalseTrigger() def test1TitleTrigger(self): cuddly = NewsStory(”, ‘The purple cow is soft and cuddly.’, ”, ”, datetime.now()) exclaim = NewsStory(”, ‘Purple!!! Cow!!!’, ”, ”, datetime.now()) symbols = NewsStory(”, ‘purple@#$%cow’, ”, ”, datetime.now()) spaces = NewsStory(”, ‘Did you see a purple cow?’, ”, ”, datetime.now()) caps = NewsStory(”, ‘The farmer owns a really PURPLE cow.’, ”, ”, datetime.now()) exact = NewsStory(”, ‘purple cow’, ”, ”, datetime.now()) plural = NewsStory(”, ‘Purple cows are cool!’, ”, ”, datetime.now()) separate = NewsStory(”, ‘The purple blob over there is a cow.’, ”, ”, datetime.now()) brown = NewsStory(”, ‘How now brown cow.’, ” ,”, datetime.now()) badorder = NewsStory(”, ‘Cow!!! Purple!!!’, ”, ”, datetime.now()) nospaces = NewsStory(”, ‘purplecowpurplecowpurplecow’, ”, ”, datetime.now()) nothing = NewsStory(”, ‘I like poison dart frogs.’, ”, ”, datetime.now()) s1 = TitleTrigger(‘PURPLE COW’) s2 = TitleTrigger(‘purple cow’) for trig in [s1, s2]: self.assertTrue(trig.evaluate(cuddly), “TitleTrigger failed to fire when the phrase appeared in the title.”) self.assertTrue(trig.evaluate(exclaim), “TitleTrigger failed to fire when the words were separated by exclamation marks.”) self.assertTrue(trig.evaluate(symbols), “TitleTrigger failed to fire when the words were separated by assorted punctuation.”) self.assertTrue(trig.evaluate(spaces), “TitleTrigger failed to fire when the words were separated by multiple spaces.”) self.assertTrue(trig.evaluate(caps), “TitleTrigger failed to fire when the phrase appeared with both uppercase and lowercase letters.”) self.assertTrue(trig.evaluate(exact), “TitleTrigger failed to fire when the words in the phrase were the only words in the title.”) self.assertFalse(trig.evaluate(plural), “TitleTrigger fired when the words in the phrase were contained within other words.”) self.assertFalse(trig.evaluate(separate), “TitleTrigger fired when the words in the phrase were separated by other words.”) self.assertFalse(trig.evaluate(brown), “TitleTrigger fired when only part of the phrase was found.”) self.assertFalse(trig.evaluate(badorder), “TitleTrigger fired when the words in the phrase appeared out of order.”) self.assertFalse(trig.evaluate(nospaces), “TitleTrigger fired when words were not separated by spaces or punctuation.”) self.assertFalse(trig.evaluate(nothing), “TitleTrigger fired when none of the words in the phrase appeared.”) def test2DescriptionTrigger(self): cuddly = NewsStory(”, ”, ‘The purple cow is soft and cuddly.’, ”, datetime.now()) exclaim = NewsStory(”, ”, ‘Purple!!! Cow!!!’, ”, datetime.now()) symbols = NewsStory(”, ”, ‘purple@#$%cow’, ”, datetime.now()) spaces = NewsStory(”, ”, ‘Did you see a purple cow?’, ”, datetime.now()) caps = NewsStory(”, ”, ‘The farmer owns a really PURPLE cow.’, ”, datetime.now()) exact = NewsStory(”, ”, ‘purple cow’, ”, datetime.now()) plural = NewsStory(”, ”, ‘Purple cows are cool!’, ”, datetime.now()) separate = NewsStory(”, ”, ‘The purple blob over there is cow.’, ”, datetime.now()) brown = NewsStory(”, ”, ‘How now brown cow.’, ”, datetime.now()) badorder = NewsStory(”, ”, ‘Cow!!! Purple!!!’, ”, datetime.now()) nospaces = NewsStory(”, ”, ‘purplecowpurplecowpurplecow’, ”, datetime.now()) nothing = NewsStory(”, ”, ‘I like poison dart frogs.’, ”, datetime.now()) s1 = DescriptionTrigger(‘PURPLE COW’) s2 = DescriptionTrigger(‘purple cow’) for trig in [s1, s2]: self.assertTrue(trig.evaluate(cuddly), “DescriptionTrigger failed to fire when the phrase appeared in the description.”) self.assertTrue(trig.evaluate(exclaim), “DescriptionTrigger failed to fire when the words were separated by exclamation marks.”) self.assertTrue(trig.evaluate(symbols), “DescriptionTrigger failed to fire when the words were separated by assorted punctuation.”) self.assertTrue(trig.evaluate(spaces), “DescriptionTrigger failed to fire when the words were separated by multiple spaces.”) self.assertTrue(trig.evaluate(caps), “DescriptionTrigger failed to fire when the phrase appeared with both uppercase and lowercase letters.”) self.assertTrue(trig.evaluate(exact), “DescriptionTrigger failed to fire when the words in the phrase were the only words in the description.”) self.assertFalse(trig.evaluate(plural), “DescriptionTrigger fired when the words in the phrase were contained within other words.”) self.assertFalse(trig.evaluate(separate), “DescriptionTrigger fired when the words in the phrase were separated by other words.”) self.assertFalse(trig.evaluate(brown), “DescriptionTrigger fired when only part of the phrase was found.”) self.assertFalse(trig.evaluate(badorder), “DescriptionTrigger fired when the words in the phrase appeared out of order.”) self.assertFalse(trig.evaluate(nospaces), “DescriptionTrigger fired when words were not separated by spaces or punctuation.”) self.assertFalse(trig.evaluate(nothing), “DescriptionTrigger fired when none of the words in the phrase appeared.”) def test3altBeforeAndAfterTrigger(self): dt = timedelta(seconds=5) now = datetime(2016, 10, 12, 23, 59, 59) now = now.replace(tzinfo=pytz.timezone(“EST”)) ancient_time = datetime(1987, 10, 15) ancient_time = ancient_time.replace(tzinfo=pytz.timezone(“EST”)) ancient = NewsStory(”, ”, ”, ”, ancient_time) just_now = NewsStory(”, ”, ”, ”, now – dt) in_a_bit = NewsStory(”, ”, ”, ”, now + dt) future_time = datetime(2087, 10, 15) future_time = future_time.replace(tzinfo=pytz.timezone(“EST”)) future = NewsStory(”, ”, ”, ”, future_time) s1 = BeforeTrigger(’12 Oct 2016 23:59:59′) s2 = AfterTrigger(’12 Oct 2016 23:59:59′) self.assertTrue(s1.evaluate(ancient), “BeforeTrigger failed to fire on news from long ago”) self.assertTrue(s1.evaluate(just_now), “BeforeTrigger failed to fire on news happened right before specified time”) self.assertFalse(s1.evaluate(in_a_bit), “BeforeTrigger fired to fire on news happened right after specified time”) self.assertFalse(s1.evaluate(future), “BeforeTrigger fired to fire on news from the future”) self.assertFalse(s2.evaluate(ancient), “AfterTrigger fired to fire on news from long ago”) self.assertFalse(s2.evaluate(just_now), “BeforeTrigger fired to fire on news happened right before specified time”) self.assertTrue(s2.evaluate(in_a_bit), “AfterTrigger failed to fire on news just after specified time”) self.assertTrue(s2.evaluate(future), “AfterTrigger failed to fire on news from long ago”) def test3BeforeAndAfterTrigger(self): dt = timedelta(seconds=5) now = datetime(2016, 10, 12, 23, 59, 59) ancient = NewsStory(”, ”, ”, ”, datetime(1987, 10, 15)) just_now = NewsStory(”, ”, ”, ”, now – dt) in_a_bit = NewsStory(”, ”, ”, ”, now + dt) future = NewsStory(”, ”, ”, ”, datetime(2087, 10, 15)) s1 = BeforeTrigger(’12 Oct 2016 23:59:59′) s2 = AfterTrigger(’12 Oct 2016 23:59:59′) self.assertTrue(s1.evaluate(ancient), “BeforeTrigger failed to fire on news from long ago”) self.assertTrue(s1.evaluate(just_now), “BeforeTrigger failed to fire on news happened right before specified time”) self.assertFalse(s1.evaluate(in_a_bit), “BeforeTrigger fired to fire on news happened right after specified time”) self.assertFalse(s1.evaluate(future), “BeforeTrigger fired to fire on news from the future”) self.assertFalse(s2.evaluate(ancient), “AfterTrigger fired to fire on news from long ago”) self.assertFalse(s2.evaluate(just_now), “BeforeTrigger fired to fire on news happened right before specified time”) self.assertTrue(s2.evaluate(in_a_bit), “AfterTrigger failed to fire on news just after specified time”) self.assertTrue(s2.evaluate(future), “AfterTrigger failed to fire on news from long ago”) def test4NotTrigger(self): n = NotTrigger(self.tt) b = NewsStory(“guid”, “title”, “description”, “link”, datetime.now()) self.assertFalse(n.evaluate(b), “A NOT trigger applied to ‘always true’ DID NOT return false”) y = NotTrigger(self.ft) self.assertTrue(y.evaluate(b), “A NOT trigger applied to ‘always false’ DID NOT return true”) def test5AndTrigger(self): yy = AndTrigger(self.tt, self.tt2) yn = AndTrigger(self.tt, self.ft) ny = AndTrigger(self.ft, self.tt) nn = AndTrigger(self.ft, self.ft2) b = NewsStory(“guid”, “title”, “description”, “link”, datetime.now()) self.assertTrue(yy.evaluate(b), “AND of ‘always true’ and ‘always true’ should be true”) self.assertFalse(yn.evaluate(b), “AND of ‘always true’ and ‘always false’ should be false”) self.assertFalse(ny.evaluate(b), “AND of ‘always false’ and ‘always true’ should be false”) self.assertFalse(nn.evaluate(b), “AND of ‘always false’ and ‘always false’ should be false”) def test6OrTrigger(self): yy = OrTrigger(self.tt, self.tt2) yn = OrTrigger(self.tt, self.ft) ny = OrTrigger(self.ft, self.tt) nn = OrTrigger(self.ft, self.ft2) b = NewsStory(“guid”, “title”, “description”, “link”, datetime.now()) self.assertTrue(yy.evaluate(b), “OR of ‘always true’ and ‘always true’ should be true”) self.assertTrue(yn.evaluate(b), “OR of ‘always true’ and ‘always false’ should be true”) self.assertTrue(ny.evaluate(b), “OR of ‘always false’ and ‘always true’ should be true”) self.assertFalse(nn.evaluate(b), “OR of ‘always false’ and ‘always false’ should be false”) def test7FilterStories(self): tt = TitleTrigger(“New York City”) a = NewsStory(”, “asfd New York City asfdasdfasdf”, ”, ”, datetime.now()) b = NewsStory(”, “asdfasfd new york city! asfdasdfasdf”, ”, ”, datetime.now()) noa = NewsStory(”, “something somethingnew york city”, ”, ”, datetime.now()) nob = NewsStory(”, “something something new york cities”, ”, ”, datetime.now()) st = DescriptionTrigger(“New York City”) a = NewsStory(”, ”, “asfd New York City asfdasdfasdf”, ”, datetime.now()) b = NewsStory(”, ”, “asdfasfd new york city! asfdasdfasdf”, ”, datetime.now()) noa = NewsStory(”, ”, “something somethingnew york city”, ”, datetime.now()) nob = NewsStory(”, ”, “something something new york cities”, ”, datetime.now()) triggers = [tt, st, self.tt, self.ft] stories = [a, b, noa, nob] filtered_stories = filter_stories(stories, triggers) for story in stories: self.assertTrue(story in filtered_stories) filtered_stories = filter_stories(stories, [self.ft]) self.assertEqual(len(filtered_stories), 0) def test8FilterStories2(self): a = NewsStory(”, “asfd New York City asfdasdfasdf”, ”, ”, datetime.now()) b = NewsStory(”, “asdfasfd new york city! asfdasdfasdf”, ”, ”, datetime.now()) noa = NewsStory(”, “something somethingnew york city”, ”, ”, datetime.now()) nob = NewsStory(”, “something something new york cities”, ”, ”, datetime.now()) class MatchTrigger(Trigger): def __init__(self, story): self.story = story def evaluate(self, story): return story == self.story triggers = [MatchTrigger(a), MatchTrigger(nob)] stories = [a, b, noa, nob] filtered_stories = filter_stories(stories, triggers) self.assertTrue(a in filtered_stories) self.assertTrue(nob in filtered_stories) self.assertEqual(2, len(filtered_stories)) if __name__ == “__main__”: suite = unittest.TestSuite() suite.addTest(unittest.makeSuite(ProblemSet5NewsStory)) suite.addTest(unittest.makeSuite(ProblemSet5)) unittest.TextTestRunner(verbosity=2).run(suite)

pset5/triggers.txt

// trigger file – if you’ve done problem 9 but no stories are popping up, you // should edit this file to contain triggers that will fire on current news // stories! // title trigger named t1 t1,TITLE,election // description trigger named t2 t2,DESCRIPTION,Trump // description trigger named t3 t3,DESCRIPTION,Clinton // after trigger named t4 t4,AFTER,3 Oct 2016 17:00:10 // composite trigger named t4 t5,AND,t2,t3 // composite trigger named t4 t6,AND,t1,t4 // the trigger list contains t1 and t4 ADD,t5,t6

 
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Data Analysis Quiz

QUESTION 2

  1. The key factors that will impact your critical thinking and shape your ambitions (Select all that apply) :1.Deliverables2.Resources

    3.Consumption

    4.Constraints5.People6.Context

1 points  

QUESTION 3

  1. __________: The visualizer here is attempting to assist with the viewers’ process of understanding as much as possible.

    1.Exhibitory

    2.Explanatory3.Exponentiation4.Exploratory

1 points  

QUESTION 4

  1. What circumstances sub category falls under Resources?  (Select all that apply)1.audience

    2.skills3.technology

    4.quantity

1 points  

QUESTION 5

  1. Some activities to help harness ideas:  (Select all that apply)1.Research and inspiration2.Sketching

    3.Keywords

    4.Mental visualization

1 points  

QUESTION 6

  1. Scenarios where the characteristics differ sufficiently to offer different contextual challenges (Select all that apply) :1.stakeholder intrigue

    2.curiosity intrigue

    3.potential intrigue

    4.anticipated intrigue5.personal intrigue6.audience intrigue

1 points  

QUESTION 7

  1. What circumstances sub category falls under People?  (Select all that apply)1.rules

    2.pressures

    3.stakeholders4.audience

1 points  

QUESTION 8

  1. What circumstances sub category falls under Constraints?  (Select all that apply)1.rules

    2.pressures3.format4.technology

1 points  

QUESTION 9

  1. What circumstances sub category falls under Consumption?  (Select all that apply)1.setting

    2.stakeholders

    3.frequency4.skills

1 points  

QUESTION 10

  1. What circumstances sub category falls under Deliverables?  (Select all that apply)1.format

    2.quantity3.setting4.frequency

 
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Broadhand-X Case Assignment Help

Broadhand-X Case Assignment Help Broadhand-X Case Assignment Help

Questions:

1. What are the motives that drove Broadband-X to implement ERP software?

2. Do you think custom built ERP software could have been a viable alternative for Broadband-X? What do you think about the way Tumbler selected the ERP system and what could he have done differently?

3. What are the biggest challenges and risks Broadband-X will face during the implementation of the project? How can the challenges be managed?

4. Develop an ERP implementation project plan most fitting to Broadband-X’s situation, accompanied by an implementation strategy (communication, project roles, training, etc.) – Use this question to develop your project planning skills. Use the data in the Project Plan section and in Exhibit 3. As part of your answer, a Gantt chart created using Microsoft Project is required.

 
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Producer Consumer Problem Assignment Help

Producer Consumer Problem Assignment Help

Process Synchronization: Producer-Consumer Problem The purpose of this programming project is to explore process synchronization. This will be accomplished by writing a program on the Producer / Consumer problem described below. Your simulation will be implemented using Pthreads. This assignment is a modification to the programming project “The Producer – Consumer Problem” found at the end of Chapter 7 of our textbook. 1. Your program must be written using C or C++ and you are required to use the Pthread with mutex and semaphore libraries. In chapter 3, we discussed how a “bounded buffer” could be used to enable producer and consumer processes to share memory. We described a technique using a circular buffer that can hold BUFFER_SIZE-1 items. By using a shared memory location count, the buffer can hold all BUFFER_SIZE items. This count is initialized to 0 and is incremented every time an item is placed into the buffer and decremented every time an item is removed from the buffer. The count data item can also be implemented as a counting semaphore. The producer can place items into the buffer only if the buffer has a free memory location to store the item. The producer cannot add items to a full buffer. The consumer can remove items from the buffer if the buffer is not empty. The consumer must wait to consume items if the buffer is empty. The “items” stored in this buffer will be integers. Your producer process will have to insert random numbers into the buffer. The consumer process will consume a number. Assignment Specifications The buffer used between producer and consumer processes will consist of a fixed-size array of type buffer_item. The queue of buffer_item objects will be manipulated using a circular array. The buffer will be manipulated with two functions, buffer_insert_item() and buffer_remove_item(), which are called by the producer and consumer threads, respectively. A skeleton outlining these functions can be found in buffer.h (provided with this assignment). The buffer_insert_item() and buffer_remove_item() functions will synchronize the producer and consumer using the algorithms. The buffer will also require an initialization function (not supplied in buffer.h) that initializes the mutual exclusion object “mutex” along with the “empty” and “full” semaphores. The producer thread will alternate between sleeping for a random period of time and generating and inserting (trying to) an integer into the buffer. Random numbers will be generated using the rand_r() function. See the text on page 290 for an overview of the producer algorithm. The consumer thread will alternate between sleeping for a random period of time (thread safe of course) and (trying to) removing a number out of the buffer. See the text on page 290 for an overview of the consumer algorithm. The main function will initialize the buffer and create the separate producer and consumer threads. Once it has created the producer and consumer threads, the main() function will sleep for duration of the simulation. Upon awakening, the main thread will signal other threads to quit by setting a simulation flag which is a global variable. The main thread will join with the other threads and then display the simulation statistics. The main() function will be passed two parameters on the command line: • The length of time the main thread is to sleep before terminating (simulation length in seconds) • The maximum length of time the producer and consumer threads will sleep prior to producing or consuming a buffer_item A skeleton for the main function appears as: #include <buffer.h> int main( int argc, char *argv[] ){ Get command line arguments Initialize buffer Create producer thread(s) Create consumer thread(s) Sleep Join Threads Display Statistics Exit } Creating Pthreads using the Pthreads API is discussed in Chapter 4 and in Assignment-1. Please refer to those references for specific instructions regarding creation of the producer and consumer Pthreads. The following code sample illustrates how mutex locks available in the Pthread API can be used to protect a critical section: #include <pthread.h> pthread_mutex_t mutex; /* create the mutex lock */ pthread_mutex_init( &mutex, NULL ); /* aquire the mutex lock */ pthread_mutex_lock( &mutex ); /*** CRITICAL SECTION ***/ /* release the mutex lock */ pthread_mutex_unlock( &mutex ); Pthreads uses the pthread_mutex_t data type for mutex locks. A mutex is created with the pthread_mutex_init() function, with the first parameter being a pointer to the mutex. By passing NULL as a second parameter, we initialize the mutex to its default attributes. The mutex is acquired and released with the pthread_mutex_lock() and pthread_mutex_unlock() functions. If the mutex lock is unavailable when pthread_mutex_lock() is invoked, the calling thread is blocked until the owner invokes pthread_mutex_unlock(). All mutex functions return a value of 0 with correct operation; if an error occurs, these functions return a nonzero error code. Pthreads provides two types of semaphores: named and unnamed. For this project, we will use unnamed semaphores. The code below illustrates how a semaphore is created: #include <semaphore.h> sem_t sem; /* create the semaphore and initialize it to 5 */ sem_init( &sem, 0, 5 ); The sem_init() function creates and initializes a semaphore. This function is passed three parameters: A pointer to the semaphore, a flag indicating the level of sharing, and the semaphore’s initial value. In this example, by passing the flag 0, we are indicating that this semaphore can only be shared by threads belonging to the same process that created the semaphore. A nonzero value would allow other processes to access the semaphore as well. In this example, we initialize the semaphore to the value 5. In Chapter-6 (Section 6.6), we described the classical wait() and signal() semaphore operations. Pthread names the wait() and signal() operations sem_wait() and sem_post(), respectively. The code example below creates a binary semaphore mutex with an initial value 1 and illustrates it use in protecting a critical section: #include <semaphore.h> sem_t mutex; /* create the semaphore */ sem_init( &mutex, 0, 1 ); /* acquire the semaphore */ sem_wait( &mutex ); /*** CRITICAL SECTION ***/ /* release the semaphore */ sem_post( &mutex ); Program Output Your simulation should output when various conditions occur: buffer empty/full, location of producer/consumer, etc. Submission Guidelines and Requirements 1. Your program must be written using C or C++ and you are required to use the Pthread with mutex and semaphore libraries 2. You may use the C/C++ STL (Standard Template Library) in your solution. 3. You should use Netbeans to implement the assignment. You can download Netbeans with C/C++ features from the following link: https://netbeans.org/downloads/8.2/ 4. Create project in Netbeans for completing this assignment. 5. Add comments (about the function/variable/class) to your code as much as possible

 
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Computer Science homework help

Computer Science homework help

FUNDAMENTALS OF

Database Systems SIXTH EDITION

 

 

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FUNDAMENTALS OF

Database Systems SIXTH EDITION

Ramez Elmasri Department of Computer Science and Engineering The University of Texas at Arlington

Shamkant B. Navathe College of Computing Georgia Institute of Technology

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Copyright © 2011, 2007, 2004, 2000, 1994, and 1989 Pearson Education, Inc., publishing as Addison-Wesley. All rights reserved. Manufactured in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use material from this work, please submit a written request to Pear- son Education, Inc., Permissions Department, 501 Boylston Street, Suite 900, Boston, Massa- chusetts 02116.

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Library of Congress Cataloging-in-Publication Data

Elmasri, Ramez. Fundamentals of database systems / Ramez Elmasri, Shamkant B. Navathe.—6th ed.

p. cm. Includes bibliographical references and index. ISBN-13: 978-0-136-08620-8

1. Database management. I. Navathe, Sham. II. Title.

QA76.9.D3E57 2010 005.74—dc22Addison-Wesley

is an imprint of

10 9 8 7 6 5 4 3 2 1—CW—14 13 12 11 10 ISBN 10: 0-136-08620-9 ISBN 13: 978-0-136-08620-8

 

 

To Katrina, Thomas, and Dora (and also to Ficky)

R. E.

To my wife Aruna, mother Vijaya, and to my entire family

for their love and support

S.B.N.

 

 

This page intentionally left blank

 

 

vii

This book introduces the fundamental concepts nec-essary for designing, using, and implementing database systems and database applications. Our presentation stresses the funda- mentals of database modeling and design, the languages and models provided by the database management systems, and database system implementation tech- niques. The book is meant to be used as a textbook for a one- or two-semester course in database systems at the junior, senior, or graduate level, and as a reference book. Our goal is to provide an in-depth and up-to-date presentation of the most important aspects of database systems and applications, and related technologies. We assume that readers are familiar with elementary programming and data- structuring concepts and that they have had some exposure to the basics of com- puter organization.

New to This Edition The following key features have been added in the sixth edition:

■ A reorganization of the chapter ordering to allow instructors to start with projects and laboratory exercises very early in the course

■ The material on SQL, the relational database standard, has been moved early in the book to Chapters 4 and 5 to allow instructors to focus on this impor- tant topic at the beginning of a course

■ The material on object-relational and object-oriented databases has been updated to conform to the latest SQL and ODMG standards, and consoli- dated into a single chapter (Chapter 11)

■ The presentation of XML has been expanded and updated, and moved ear- lier in the book to Chapter 12

■ The chapters on normalization theory have been reorganized so that the first chapter (Chapter 15) focuses on intuitive normalization concepts, while the second chapter (Chapter 16) focuses on the formal theories and normaliza- tion algorithms

■ The presentation of database security threats has been updated with a dis- cussion on SQL injection attacks and prevention techniques in Chapter 24, and an overview of label-based security with examples

Preface

 

 

■ Our presentation on spatial databases and multimedia databases has been expanded and updated in Chapter 26

■ A new Chapter 27 on information retrieval techniques has been added, which discusses models and techniques for retrieval, querying, browsing, and indexing of information from Web documents; we present the typical processing steps in an information retrieval system, the evaluation metrics, and how information retrieval techniques are related to databases and to Web search

The following are key features of the book:

■ A self-contained, flexible organization that can be tailored to individual needs

■ A Companion Website (http://www.aw.com/elmasri) includes data to be loaded into various types of relational databases for more realistic student laboratory exercises

■ A simple relational algebra and calculus interpreter

■ A collection of supplements, including a robust set of materials for instruc- tors and students, such as PowerPoint slides, figures from the text, and an instructor’s guide with solutions

Organization of the Sixth Edition There are significant organizational changes in the sixth edition, as well as improve- ment to the individual chapters. The book is now divided into eleven parts as follows:

■ Part 1 (Chapters 1 and 2) includes the introductory chapters

■ The presentation on relational databases and SQL has been moved to Part 2 (Chapters 3 through 6) of the book; Chapter 3 presents the formal relational model and relational database constraints; the material on SQL (Chapters 4 and 5) is now presented before our presentation on relational algebra and cal- culus in Chapter 6 to allow instructors to start SQL projects early in a course if they wish (this reordering is also based on a study that suggests students master SQL better when it is taught before the formal relational languages)

■ The presentation on entity-relationship modeling and database design is now in Part 3 (Chapters 7 through 10), but it can still be covered before Part 2 if the focus of a course is on database design

■ Part 4 covers the updated material on object-relational and object-oriented databases (Chapter 11) and XML (Chapter 12)

■ Part 5 includes the chapters on database programming techniques (Chapter 13) and Web database programming using PHP (Chapter 14, which was moved earlier in the book)

■ Part 6 (Chapters 15 and 16) are the normalization and design theory chapters (we moved all the formal aspects of normalization algorithms to Chapter 16)

viii Preface

 

 

Preface ix

■ Part 7 (Chapters 17 and 18) contains the chapters on file organizations, indexing, and hashing

■ Part 8 includes the chapters on query processing and optimization tech- niques (Chapter 19) and database tuning (Chapter 20)

■ Part 9 includes Chapter 21 on transaction processing concepts; Chapter 22 on concurrency control; and Chapter 23 on database recovery from failures

■ Part 10 on additional database topics includes Chapter 24 on database secu- rity and Chapter 25 on distributed databases

■ Part 11 on advanced database models and applications includes Chapter 26 on advanced data models (active, temporal, spatial, multimedia, and deduc- tive databases); the new Chapter 27 on information retrieval and Web search; and the chapters on data mining (Chapter 28) and data warehousing (Chapter 29)

Contents of the Sixth Edition Part 1 describes the basic introductory concepts necessary for a good understanding of database models, systems, and languages. Chapters 1 and 2 introduce databases, typical users, and DBMS concepts, terminology, and architecture.

Part 2 describes the relational data model, the SQL standard, and the formal rela- tional languages. Chapter 3 describes the basic relational model, its integrity con- straints, and update operations. Chapter 4 describes some of the basic parts of the SQL standard for relational databases, including data definition, data modification operations, and simple SQL queries. Chapter 5 presents more complex SQL queries, as well as the SQL concepts of triggers, assertions, views, and schema modification. Chapter 6 describes the operations of the relational algebra and introduces the rela- tional calculus.

Part 3 covers several topics related to conceptual database modeling and database design. In Chapter 7, the concepts of the Entity-Relationship (ER) model and ER diagrams are presented and used to illustrate conceptual database design. Chapter 8 focuses on data abstraction and semantic data modeling concepts and shows how the ER model can be extended to incorporate these ideas, leading to the enhanced- ER (EER) data model and EER diagrams. The concepts presented in Chapter 8 include subclasses, specialization, generalization, and union types (categories). The notation for the class diagrams of UML is also introduced in Chapters 7 and 8. Chapter 9 discusses relational database design using ER- and EER-to-relational mapping. We end Part 3 with Chapter 10, which presents an overview of the differ- ent phases of the database design process in enterprises for medium-sized and large database applications.

Part 4 covers the object-oriented, object-relational, and XML data models, and their affiliated languages and standards. Chapter 11 first introduces the concepts for object databases, and then shows how they have been incorporated into the SQL standard in order to add object capabilities to relational database systems. It then

 

 

x Preface

covers the ODMG object model standard, and its object definition and query lan- guages. Chapter 12 covers the XML (eXtensible Markup Language) model and lan- guages, and discusses how XML is related to database systems. It presents XML concepts and languages, and compares the XML model to traditional database models. We also show how data can be converted between the XML and relational representations.

Part 5 is on database programming techniques. Chapter 13 covers SQL program- ming topics, such as embedded SQL, dynamic SQL, ODBC, SQLJ, JDBC, and SQL/CLI. Chapter 14 introduces Web database programming, using the PHP script- ing language in our examples.

Part 6 covers normalization theory. Chapters 15 and 16 cover the formalisms, theo- ries, and algorithms developed for relational database design by normalization. This material includes functional and other types of dependencies and normal forms of relations. Step-by-step intuitive normalization is presented in Chapter 15, which also defines multivalued and join dependencies. Relational design algorithms based on normalization, along with the theoretical materials that the algorithms are based on, are presented in Chapter 16.

Part 7 describes the physical file structures and access methods used in database sys- tems. Chapter 17 describes primary methods of organizing files of records on disk, including static and dynamic hashing. Chapter 18 describes indexing techniques for files, including B-tree and B+-tree data structures and grid files.

Part 8 focuses on query processing and database performance tuning. Chapter 19 introduces the basics of query processing and optimization, and Chapter 20 dis- cusses physical database design and tuning.

Part 9 discusses transaction processing, concurrency control, and recovery tech- niques, including discussions of how these concepts are realized in SQL. Chapter 21 introduces the techniques needed for transaction processing systems, and defines the concepts of recoverability and serializability of schedules. Chapter 22 gives an overview of the various types of concurrency control protocols, with a focus on two-phase locking. We also discuss timestamp ordering and optimistic concurrency control techniques, as well as multiple-granularity locking. Finally, Chapter 23 focuses on database recovery protocols, and gives an overview of the concepts and techniques that are used in recovery.

Parts 10 and 11 cover a number of advanced topics. Chapter 24 gives an overview of database security including the discretionary access control model with SQL com- mands to GRANT and REVOKE privileges, the mandatory access control model with user categories and polyinstantiation, a discussion of data privacy and its rela- tionship to security, and an overview of SQL injection attacks. Chapter 25 gives an introduction to distributed databases and discusses the three-tier client/server architecture. Chapter 26 introduces several enhanced database models for advanced applications. These include active databases and triggers, as well as temporal, spa- tial, multimedia, and deductive databases. Chapter 27 is a new chapter on informa- tion retrieval techniques, and how they are related to database systems and to Web

 

 

search methods. Chapter 28 on data mining gives an overview of the process of data mining and knowledge discovery, discusses algorithms for association rule mining, classification, and clustering, and briefly covers other approaches and commercial tools. Chapter 29 introduces data warehousing and OLAP concepts.

Appendix A gives a number of alternative diagrammatic notations for displaying a conceptual ER or EER schema. These may be substituted for the notation we use, if the instructor prefers. Appendix B gives some important physical parameters of disks. Appendix C gives an overview of the QBE graphical query language. Appen- dixes D and E (available on the book’s Companion Website located at http://www.aw.com/elmasri) cover legacy database systems, based on the hierar- chical and network database models. They have been used for more than thirty years as a basis for many commercial database applications and transaction- processing systems. We consider it important to expose database management stu- dents to these legacy approaches so they can gain a better insight of how database technology has progressed.

Guidelines for Using This Book There are many different ways to teach a database course. The chapters in Parts 1 through 7 can be used in an introductory course on database systems in the order that they are given or in the preferred order of individual instructors. Selected chap- ters and sections may be left out, and the instructor can add other chapters from the rest of the book, depending on the emphasis of the course. At the end of the open- ing section of many of the book’s chapters, we list sections that are candidates for being left out whenever a less-detailed discussion of the topic is desired. We suggest covering up to Chapter 15 in an introductory database course and including selected parts of other chapters, depending on the background of the students and the desired coverage. For an emphasis on system implementation techniques, chap- ters from Parts 7, 8, and 9 should replace some of the earlier chapters.

Chapters 7 and 8, which cover conceptual modeling using the ER and EER models, are important for a good conceptual understanding of databases. However, they may be partially covered, covered later in a course, or even left out if the emphasis is on DBMS implementation. Chapters 17 and 18 on file organizations and indexing may also be covered early, later, or even left out if the emphasis is on database mod- els and languages. For students who have completed a course on file organization, parts of these chapters can be assigned as reading material or some exercises can be assigned as a review for these concepts.

If the emphasis of a course is on database design, then the instructor should cover Chapters 7 and 8 early on, followed by the presentation of relational databases. A total life-cycle database design and implementation project would cover conceptual design (Chapters 7 and 8), relational databases (Chapters 3, 4, and 5), data model mapping (Chapter 9), normalization (Chapter 15), and application programs implementation with SQL (Chapter 13). Chapter 14 also should be covered if the emphasis is on Web database programming and applications. Additional documen- tation on the specific programming languages and RDBMS used would be required.

Preface xi

 

 

The book is written so that it is possible to cover topics in various sequences. The chapter dependency chart below shows the major dependencies among chapters. As the diagram illustrates, it is possible to start with several different topics following the first two introductory chapters. Although the chart may seem complex, it is important to note that if the chapters are covered in order, the dependencies are not lost. The chart can be consulted by instructors wishing to use an alternative order of presentation.

For a one-semester course based on this book, selected chapters can be assigned as reading material. The book also can be used for a two-semester course sequence. The first course, Introduction to Database Design and Database Systems, at the soph- omore, junior, or senior level, can cover most of Chapters 1 through 15. The second course, Database Models and Implementation Techniques, at the senior or first-year graduate level, can cover most of Chapters 16 through 29. The two-semester sequence can also been designed in various other ways, depending on the prefer- ences of the instructors.

xii Preface

1, 2 Introductory

7, 8 ER, EER Models

3 Relational

Model

6 Relational Algebra 13, 14

DB, Web Programming

9 ER–, EER-to-

Relational

17, 18 File Organization,

Indexing

28, 29 Data Mining, Warehousing

24, 25 Security,

DDB

10 DB Design,

UML

21, 22, 23 Transactions, CC, Recovery

11, 12 ODB, ORDB,

XML

4, 5 SQL

26, 27 Advanced Models,

IR

15, 16 FD, MVD,

Normalization

19, 20 Query Processing,

Optimization, DB Tuning

 

 

Supplemental Materials Support material is available to all users of this book and additional material is available to qualified instructors.

■ PowerPoint lecture notes and figures are available at the Computer Science support Website at http://www.aw.com/cssupport.

■ A lab manual for the sixth edition is available through the Companion Web- site (http://www.aw.com/elmasri). The lab manual contains coverage of popular data modeling tools, a relational algebra and calculus interpreter, and examples from the book implemented using two widely available data- base management systems. Select end-of-chapter laboratory problems in the book are correlated to the lab manual.

■ A solutions manual is available to qualified instructors. Visit Addison- Wesley’s instructor resource center (http://www.aw.com/irc), contact your local Addison-Wesley sales representative, or e-mail computing@aw.com for information about how to access the solutions.

Additional Support Material Gradiance, an online homework and tutorial system that provides additional prac- tice and tests comprehension of important concepts, is available to U.S. adopters of this book. For more information, please e-mail computing@aw.com or contact your local Pearson representative.

Acknowledgments It is a great pleasure to acknowledge the assistance and contributions of many indi- viduals to this effort. First, we would like to thank our editor, Matt Goldstein, for his guidance, encouragement, and support. We would like to acknowledge the excellent work of Gillian Hall for production management and Rebecca Greenberg for a thorough copy editing of the book. We thank the following persons from Pearson who have contributed to the sixth edition: Jeff Holcomb, Marilyn Lloyd, Margaret Waples, and Chelsea Bell.

Sham Navathe would like to acknowledge the significant contribution of Saurav Sahay to Chapter 27. Several current and former students also contributed to vari- ous chapters in this edition: Rafi Ahmed, Liora Sahar, Fariborz Farahmand, Nalini Polavarapu, and Wanxia Xie (former students); and Bharath Rengarajan, Narsi Srinivasan, Parimala R. Pranesh, Neha Deodhar, Balaji Palanisamy and Hariprasad Kumar (current students). Discussions with his colleagues Ed Omiecinski and Leo Mark at Georgia Tech and Venu Dasigi at SPSU, Atlanta have also contributed to the revision of the material.

We would like to repeat our thanks to those who have reviewed and contributed to previous editions of Fundamentals of Database Systems.

■ First edition. Alan Apt (editor), Don Batory, Scott Downing, Dennis Heimbinger, Julia Hodges, Yannis Ioannidis, Jim Larson, Per-Ake Larson,

Preface xiii

 

 

Dennis McLeod, Rahul Patel, Nicholas Roussopoulos, David Stemple, Michael Stonebraker, Frank Tompa, and Kyu-Young Whang.

■ Second edition. Dan Joraanstad (editor), Rafi Ahmed, Antonio Albano, David Beech, Jose Blakeley, Panos Chrysanthis, Suzanne Dietrich, Vic Ghor- padey, Goetz Graefe, Eric Hanson, Junguk L. Kim, Roger King, Vram Kouramajian, Vijay Kumar, John Lowther, Sanjay Manchanda, Toshimi Minoura, Inderpal Mumick, Ed Omiecinski, Girish Pathak, Raghu Ramakr- ishnan, Ed Robertson, Eugene Sheng, David Stotts, Marianne Winslett, and Stan Zdonick.

■ Third edition. Maite Suarez-Rivas and Katherine Harutunian (editors); Suzanne Dietrich, Ed Omiecinski, Rafi Ahmed, Francois Bancilhon, Jose Blakeley, Rick Cattell, Ann Chervenak, David W. Embley, Henry A. Etlinger, Leonidas Fegaras, Dan Forsyth, Farshad Fotouhi, Michael Franklin, Sreejith Gopinath, Goetz Craefe, Richard Hull, Sushil Jajodia, Ramesh K. Karne, Harish Kotbagi, Vijay Kumar, Tarcisio Lima, Ramon A. Mata-Toledo, Jack McCaw, Dennis McLeod, Rokia Missaoui, Magdi Morsi, M. Narayanaswamy, Carlos Ordonez, Joan Peckham, Betty Salzberg, Ming-Chien Shan, Junping Sun, Rajshekhar Sunderraman, Aravindan Veerasamy, and Emilia E. Villareal.

■ Fourth edition. Maite Suarez-Rivas, Katherine Harutunian, Daniel Rausch, and Juliet Silveri (editors); Phil Bernhard, Zhengxin Chen, Jan Chomicki, Hakan Ferhatosmanoglu, Len Fisk, William Hankley, Ali R. Hurson, Vijay Kumar, Peretz Shoval, Jason T. L. Wang (reviewers); Ed Omiecinski (who contributed to Chapter 27). Contributors from the University of Texas at Arlington are Jack Fu, Hyoil Han, Babak Hojabri, Charley Li, Ande Swathi, and Steven Wu; Contributors from Georgia Tech are Weimin Feng, Dan Forsythe, Angshuman Guin, Abrar Ul-Haque, Bin Liu, Ying Liu, Wanxia Xie, and Waigen Yee.

■ Fifth edition. Matt Goldstein and Katherine Harutunian (editors); Michelle Brown, Gillian Hall, Patty Mahtani, Maite Suarez-Rivas, Bethany Tidd, and Joyce Cosentino Wells (from Addison-Wesley); Hani Abu-Salem, Jamal R. Alsabbagh, Ramzi Bualuan, Soon Chung, Sumali Conlon, Hasan Davulcu, James Geller, Le Gruenwald, Latifur Khan, Herman Lam, Byung S. Lee, Donald Sanderson, Jamil Saquer, Costas Tsatsoulis, and Jack C. Wileden (reviewers); Raj Sunderraman (who contributed the laboratory projects); Salman Azar (who contributed some new exercises); Gaurav Bhatia, Fariborz Farahmand, Ying Liu, Ed Omiecinski, Nalini Polavarapu, Liora Sahar, Saurav Sahay, and Wanxia Xie (from Georgia Tech).

Last, but not least, we gratefully acknowledge the support, encouragement, and patience of our families.

R. E.

S.B.N.

xiv Preface

 

 

Contents

■ part 1 Introduction to Databases ■

chapter 1 Databases and Database Users 3 1.1 Introduction 4 1.2 An Example 6 1.3 Characteristics of the Database Approach 9 1.4 Actors on the Scene 14 1.5 Workers behind the Scene 16 1.6 Advantages of Using the DBMS Approach 17 1.7 A Brief History of Database Applications 23 1.8 When Not to Use a DBMS 26 1.9 Summary 27 Review Questions 27 Exercises 28 Selected Bibliography 28

chapter 2 Database System Concepts and Architecture 29

2.1 Data Models, Schemas, and Instances 30 2.2 Three-Schema Architecture and Data Independence 33 2.3 Database Languages and Interfaces 36 2.4 The Database System Environment 40 2.5 Centralized and Client/Server Architectures for DBMSs 44 2.6 Classification of Database Management Systems 49 2.7 Summary 52 Review Questions 53 Exercises 54 Selected Bibliography 55

xv

 

 

xvi Contents

■ part 2 The Relational Data Model and SQL ■

chapter 3 The Relational Data Model and Relational Database Constraints 59

3.1 Relational Model Concepts 60 3.2 Relational Model Constraints and Relational Database Schemas 67 3.3 Update Operations, Transactions, and Dealing

with Constraint Violations 75 3.4 Summary 79 Review Questions 80 Exercises 80 Selected Bibliography 85

chapter 4 Basic SQL 87 4.1 SQL Data Definition and Data Types 89 4.2 Specifying Constraints in SQL 94 4.3 Basic Retrieval Queries in SQL 97 4.4 INSERT, DELETE, and UPDATE Statements in SQL 107 4.5 Additional Features of SQL 110 4.6 Summary 111 Review Questions 112 Exercises 112 Selected Bibliography 114

chapter 5 More SQL: Complex Queries, Triggers, Views, and Schema Modification 115

5.1 More Complex SQL Retrieval Queries 115 5.2 Specifying Constraints as Assertions and Actions as Triggers 131 5.3 Views (Virtual Tables) in SQL 133 5.4 Schema Change Statements in SQL 137 5.5 Summary 139 Review Questions 141 Exercises 141 Selected Bibliography 143

 

 

chapter 6 The Relational Algebra and Relational Calculus 145

6.1 Unary Relational Operations: SELECT and PROJECT 147 6.2 Relational Algebra Operations from Set Theory 152 6.3 Binary Relational Operations: JOIN and DIVISION 157 6.4 Additional Relational Operations 165 6.5 Examples of Queries in Relational Algebra 171 6.6 The Tuple Relational Calculus 174 6.7 The Domain Relational Calculus 183 6.8 Summary 185 Review Questions 186 Exercises 187 Laboratory Exercises 192 Selected Bibliography 194

■ part 3 Conceptual Modeling and Database Design ■

chapter 7 Data Modeling Using the Entity-Relationship (ER) Model 199

7.1 Using High-Level Conceptual Data Models for Database Design 200 7.2 A Sample Database Application 202 7.3 Entity Types, Entity Sets, Attributes, and Keys 203 7.4 Relationship Types, Relationship Sets, Roles,

and Structural Constraints 212 7.5 Weak Entity Types 219 7.6 Refining the ER Design for the COMPANY Database 220 7.7 ER Diagrams, Naming Conventions, and Design Issues 221 7.8 Example of Other Notation: UML Class Diagrams 226 7.9 Relationship Types of Degree Higher than Two 228 7.10 Summary 232 Review Questions 234 Exercises 234 Laboratory Exercises 241 Selected Bibliography 243

Contents xvii

 

 

xviii Contents

chapter 8 The Enhanced Entity-Relationship (EER) Model 245

8.1 Subclasses, Superclasses, and Inheritance 246 8.2 Specialization and Generalization 248 8.3 Constraints and Characteristics of Specialization

and Generalization Hierarchies 251 8.4 Modeling of UNION Types Using Categories 258 8.5 A Sample UNIVERSITY EER Schema, Design Choices,

and Formal Definitions 260 8.6 Example of Other Notation: Representing Specialization

and Generalization in UML Class Diagrams 265 8.7 Data Abstraction, Knowledge Representation,

and Ontology Concepts 267 8.8 Summary 273 Review Questions 273 Exercises 274 Laboratory Exercises 281 Selected Bibliography 284

chapter 9 Relational Database Design by ER- and EER-to-Relational Mapping 285

9.1 Relational Database Design Using ER-to-Relational Mapping 286 9.2 Mapping EER Model Constructs to Relations 294 9.3 Summary 299 Review Questions 299 Exercises 299 Laboratory Exercises 301 Selected Bibliography 302

chapter 10 Practical Database Design Methodology and Use of UML Diagrams 303

10.1 The Role of Information Systems in Organizations 304 10.2 The Database Design and Implementation Process 309 10.3 Use of UML Diagrams as an Aid to Database

Design Specification 328 10.4 Rational Rose: A UML-Based Design Tool 337 10.5 Automated Database Design Tools 342

 

 

Contents xix

10.6 Summary 345 Review Questions 347 Selected Bibliography 348

■ part 4 Object, Object-Relational, and XML: Concepts, Models, Languages, and Standards ■

chapter 11 Object and Object-Relational Databases 353 11.1 Overview of Object Database Concepts 355 11.2 Object-Relational Features: Object Database Extensions

to SQL 369 11.3 The ODMG Object Model and the Object Definition

Language ODL 376 11.4 Object Database Conceptual Design 395 11.5 The Object Query Language OQL 398 11.6 Overview of the C++ Language Binding in the ODMG Standard 407 11.7 Summary 408 Review Questions 409 Exercises 411 Selected Bibliography 412

chapter 12 XML: Extensible Markup Language 415 12.1 Structured, Semistructured, and Unstructured Data 416 12.2 XML Hierarchical (Tree) Data Model 420 12.3 XML Documents, DTD, and XML Schema 423 12.4 Storing and Extracting XML Documents from Databases 431 12.5 XML Languages 432 12.6 Extracting XML Documents from Relational Databases 436 12.7 Summary 442 Review Questions 442 Exercises 443 Selected Bibliography 443

 

 

■ part 5 Database Programming Techniques ■

chapter 13 Introduction to SQL Programming Techniques 447

13.1 Database Programming: Techniques and Issues 448 13.2 Embedded SQL, Dynamic SQL, and SQLJ 451 13.3 Database Programming with Function Calls: SQL/CLI and JDBC

464 13.4 Database Stored Procedures and SQL/PSM 473 13.5 Comparing the Three Approaches 476 13.6 Summary 477 Review Questions 478 Exercises 478 Selected Bibliography 479

chapter 14 Web Database Programming Using PHP 481 14.1 A Simple PHP Example 482 14.2 Overview of Basic Features of PHP 484 14.3 Overview of PHP Database Programming 491 14.4 Summary 496 Review Questions 496 Exercises 497 Selected Bibliography 497

■ part 6 Database Design Theory and Normalization ■

chapter 15 Basics of Functional Dependencies and Normalization for Relational Databases 501

15.1 Informal Design Guidelines for Relation Schemas 503 15.2 Functional Dependencies 513 15.3 Normal Forms Based on Primary Keys 516 15.4 General Definitions of Second and Third Normal Forms 525 15.5 Boyce-Codd Normal Form 529

xx Contents

 

 

15.6 Multivalued Dependency and Fourth Normal Form 531 15.7 Join Dependencies and Fifth Normal Form 534 15.8 Summary 535 Review Questions 536 Exercises 537 Laboratory Exercises 542 Selected Bibliography 542

chapter 16 Relational Database Design Algorithms and Further Dependencies 543

16.1 Further Topics in Functional Dependencies: Inference Rules, Equivalence, and Minimal Cover 545

16.2 Properties of Relational Decompositions 551 16.3 Algorithms for Relational Database Schema Design 557 16.4 About Nulls, Dangling Tuples, and Alternative Relational

Designs 563 16.5 Further Discussion of Multivalued Dependencies and 4NF 567 16.6 Other Dependencies and Normal Forms 571 16.7 Summary 575 Review Questions 576 Exercises 576 Laboratory Exercises 578 Selected Bibliography 579

■ part 7 File Structures, Indexing, and Hashing ■

chapter 17 Disk Storage, Basic File Structures, and Hashing 583

17.1 Introduction 584 17.2 Secondary Storage Devices 587 17.3 Buffering of Blocks 593 17.4 Placing File Records on Disk 594 17.5 Operations on Files 599 17.6 Files of Unordered Records (Heap Files) 601 17.7 Files of Ordered Records (Sorted Files) 603 17.8 Hashing Techniques 606

 
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Educational Website

 

Project Description: In the following project, you will edit a handout that describes a new educational website product that Sturgeon Point Productions has developed for instructors. You will insert text, insert and format graphics, insert and modify text boxes and shapes, change document and paragraph layout, create lists, set and modify tab stops, and insert a SmartArt graphic.

 

Instructions: For the purpose of grading the project you are required to perform the following tasks: Step Instructions Points Possible 1 Start Word. Download and open the file named go_w01_grader_h3.docx. 0 2 Type Educational Websites and then press ENTER. Type Sturgeon Point Productions is offering website tie-ins with every educational video title in our catalog, at no additional cost. After the period, press SPACEBAR. Insert the text from the grader data file go_w01_grader_h3_Education.docx. 4 3 Change the Line Spacing for the entire document to 1.5 and the spacing After to 6 pt. To each of the four paragraphs that begin Sturgeon Point Productions, As educators, When submitting, and The video, apply a First Line indent of 0.5”. 6 4 Change the font size of the title to 50 and the title Line Spacing to 1.0. Center the title. From the Text Effects and Typography gallery, apply the second effect to the title—Fill – Blue, Accent 1, Shadow. 10 5 At the beginning of the paragraph below the title, insert the picture downloaded with your grader files—go_w01_grader_h3_Media.jpg. Change the picture Height to 2, and the Layout Options to Square. Format the picture with a 10 Point Soft Edges effect. 8 6 Use the Position command to display the Layout dialog box. Change the picture position so that the Horizontal Alignment is Right relative to the Margin. Change the Vertical Alignment to Top relative to the Line. 4 7 Select the five paragraphs beginning with Historic interactive timelines and ending with Quizzes and essay exams, and then apply checkmark bullets. 5 8 Locate the paragraph below the bulleted list and then click after the colon. Press ENTER and remove the first line indent. Type a numbered list with the following three numbered items: The title in which you are interested The name of the class and subject Online tools you would like to see created 5 9 With the insertion point located at the end of the numbered list, insert a Basic Chevron Process SmartArt. In the first shape, type View. In the second shape type Interact and in the third shape type Assess. Select the outside border of the SmartArt. Change the SmartArt color to Colorful Range – Accent Colors 4 to 5, and then apply the 3-D Flat Scene style. 8 10 Change the Height of the SmartArt to 1 and the Width to 6.5. Change the SmartArt Layout Options to Square, the Horizontal Alignment to Centered relative to the Page, and the Vertical Alignment to Bottom relative to the Margin. 8 11 Select the days and times at the end of the document and then set a Right tab with dot leaders at 6”. 4 12 Click in the blank line below the tabbed list, and then center the line. Insert an Online Video. Search YouTube for Pearson Higher Education Learning, and then insert the first video that displays. Change the video height to 1.5. 4 13 Below the video, insert a Rounded Rectangle shape. Change the Shape Height to 1.5 and the Shape Width to 6.5. Display the Shape Styles gallery and in the fourth row, apply the second style— Subtle Effect – Blue, Accent 1. 8 14 Use the Position command to display the Layout dialog box, and then change the position so that both the Horizontal and Vertical Alignment are Centered relative to the Margin. In the rectangle, type Sturgeon Point Productions and then press ENTER. Type Partnering with Educators to Produce Rich Media Content and then change the font size to 16. 6 15 Move to the top of the document and insert a Text Box above the title. Change the Height of the text box to 0.5 and the width to 3.6.Type Sturgeon Point Productions and then change the font size to 22. Center the text. 2 16 Use the Position command to display the Layout dialog box, and then position the text box so that the Horizontal Alignment is Centered relative to the Page and the Vertical Absolute position is 0.5 below the Page. 6 17 Change the text box Shape Fill color to Blue, Accent 5, Lighter 80%. Change the Shape Outline to the same color—Blue, Accent 5, Lighter 80%. 4 18 Deselect the text box. Apply a Box setting page border and choose the first style. Change the Color to Blue, Accent 5. 4 19 Change the Top margin to 1.25 and insert the File Name in the footer. 4 20 Save and close the document. Exit Word. Submit the file as directed. 0 Total Points 100

 

 

 

Updated: 01/05/2013 3 W_CH01_GOV1_H3_Instructions.docx

 
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