/utils/feedparser.py

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"""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__ = "5.1.3"
__license__ = """
Copyright (c) 2010-2013 Kurt McKee <contactme@kurtmckee.org>
Copyright (c) 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
import urllib2
import urlparse
import warnings

from htmlentitydefs import name2codepoint, codepoint2name, entitydefs

try:
    from io import BytesIO as _StringIO
except ImportError:
    try:
        from cStringIO import StringIO as _StringIO
    except ImportError:
        from StringIO 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 = {'': u'unknown',
                      'rss090': u'RSS 0.90',
                      'rss091n': u'RSS 0.91 (Netscape)',
                      'rss091u': u'RSS 0.91 (Userland)',
                      'rss092': u'RSS 0.92',
                      'rss093': u'RSS 0.93',
                      'rss094': u'RSS 0.94',
                      'rss20': u'RSS 2.0',
                      'rss10': u'RSS 1.0',
                      'rss': u'RSS (unknown version)',
                      'atom01': u'Atom 0.1',
                      'atom02': u'Atom 0.2',
                      'atom03': u'Atom 0.3',
                      'atom10': u'Atom 1.0',
                      'atom': u'Atom (unknown version)',
                      'cdf': u'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):
        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 link.items() if name!='rel'])
            return [norel(link) for link in dict.__getitem__(self, 'links') if link['rel']==u'enclosure']
        elif key == 'license':
            for link in dict.__getitem__(self, 'links'):
                if link['rel']==u'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):
        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: unichr(8364), # euro sign
    130: unichr(8218), # single low-9 quotation mark
    131: unichr( 402), # latin small letter f with hook
    132: unichr(8222), # double low-9 quotation mark
    133: unichr(8230), # horizontal ellipsis
    134: unichr(8224), # dagger
    135: unichr(8225), # double dagger
    136: unichr( 710), # modifier letter circumflex accent
    137: unichr(8240), # per mille sign
    138: unichr( 352), # latin capital letter s with caron
    139: unichr(8249), # single left-pointing angle quotation mark
    140: unichr( 338), # latin capital ligature oe
    142: unichr( 381), # latin capital letter z with caron
    145: unichr(8216), # left single quotation mark
    146: unichr(8217), # right single quotation mark
    147: unichr(8220), # left double quotation mark
    148: unichr(8221), # right double quotation mark
    149: unichr(8226), # bullet
    150: unichr(8211), # en dash
    151: unichr(8212), # em dash
    152: unichr( 732), # small tilde
    153: unichr(8482), # trade mark sign
    154: unichr( 353), # latin small letter s with caron
    155: unichr(8250), # single right-pointing angle quotation mark
    156: unichr( 339), # latin small ligature oe
    158: unichr( 382), # latin small letter z with caron
    159: unichr( 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, unicode):
        uri = uri.decode('utf-8', 'ignore')
    try:
        uri = urlparse.urljoin(base, uri)
    except ValueError:
        uri = u''
    if not isinstance(uri, unicode):
        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 = [u'text/html', u'application/xhtml+xml']

    def __init__(self, baseuri=None, baselang=None, encoding=u'utf-8'):
        if not self._matchnamespaces:
            for k, v in 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 = u'' # 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 u''
        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, unicode):
                v = v.decode('utf-8')
        return (k, v)

    def unknown_starttag(self, tag, attrs):
        # increment depth counter
        self.depth += 1

        # normalize attrs
        attrs = 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, unicode):
            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', u'xml').endswith(u'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'] = u'application/xhtml+xml'
        if self.incontent and self.contentparams.get('type') == u'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', u'xml').endswith(u'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'] = u'application/xhtml+xml'
        if self.incontent and self.contentparams.get('type') == u'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 '&#160;', 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 = unichr(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 = unichr(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') == u'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 = u'text/plain'
        elif contentType == 'html':
            contentType = u'text/html'
        elif contentType == 'xhtml':
            contentType = u'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 = u'rss090'
            elif loweruri == 'http://purl.org/rss/1.0/':
                self.version = u'rss10'
            elif loweruri == 'http://www.w3.org/2005/atom':
                self.version = u'atom10'
        if loweruri.find(u'backend.userland.com/rss') <> -1:
            # match any backend.userland.com namespace
            uri = u'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 u'', 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 == u'atom10' and self.contentparams.get('type', u'text') == u'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, unicode):
                pieces[i] = v.decode('utf-8')

        output = u''.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(u'atom') and self.contentparams.get('type') == u'text/plain':
            if self.lookslikehtml(output):
                self.contentparams['type'] = u'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', u'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', u'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', u'text/html'))

        if self.encoding and not isinstance(output, unicode):
            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 (u'utf-8', u'utf-8_INVALID_PYTHON_3') and isinstance(output, unicode):
            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, unicode):
            output = output.translate(_cp1252)

        # categories/tags/keywords/whatever are handled in _end_category
        if element == 'category':
            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 = 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 filter(lambda t: t.lower() not in _HTMLSanitizer.acceptable_elements,
            re.findall(r'</?(\w+)',s)):
            return

        # all entities must have been defined as valid HTML entities
        if filter(lambda e: e not in entitydefs.keys(), re.findall(r'&(\w+);', s)):
            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(u'text/'):
            return 0
        if self.contentparams['type'].endswith(u'+xml'):
            return 0
        if self.contentparams['type'].endswith(u'/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': u'rss091u',
                      '0.92': u'rss092',
                      '0.93': u'rss093',
                      '0.94': u'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(u'rss'):
            attr_version = attrsD.get('version', '')
            version = versionmap.get(attr_version)
            if version:
                self.version = version
            elif attr_version.startswith('2.'):
                self.version = u'rss20'
            else:
                self.version = u'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': u'atom01',
                      '0.2': u'atom02',
                      '0.3': u'atom03'}
        if not self.version:
            attr_version = attrsD.get('version')
            version = versionmap.get(attr_version)
            if version:
                self.version = version
            else:
                self.version = u'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'] = v…