Mercurial > repos > guerler > springsuite
diff planemo/lib/python3.7/site-packages/bs4/builder/_htmlparser.py @ 0:d30785e31577 draft
"planemo upload commit 6eee67778febed82ddd413c3ca40b3183a3898f1"
author | guerler |
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date | Fri, 31 Jul 2020 00:18:57 -0400 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/planemo/lib/python3.7/site-packages/bs4/builder/_htmlparser.py Fri Jul 31 00:18:57 2020 -0400 @@ -0,0 +1,477 @@ +# encoding: utf-8 +"""Use the HTMLParser library to parse HTML files that aren't too bad.""" + +# Use of this source code is governed by the MIT license. +__license__ = "MIT" + +__all__ = [ + 'HTMLParserTreeBuilder', + ] + +from html.parser import HTMLParser + +try: + from html.parser import HTMLParseError +except ImportError as e: + # HTMLParseError is removed in Python 3.5. Since it can never be + # thrown in 3.5, we can just define our own class as a placeholder. + class HTMLParseError(Exception): + pass + +import sys +import warnings + +# Starting in Python 3.2, the HTMLParser constructor takes a 'strict' +# argument, which we'd like to set to False. Unfortunately, +# http://bugs.python.org/issue13273 makes strict=True a better bet +# before Python 3.2.3. +# +# At the end of this file, we monkeypatch HTMLParser so that +# strict=True works well on Python 3.2.2. +major, minor, release = sys.version_info[:3] +CONSTRUCTOR_TAKES_STRICT = major == 3 and minor == 2 and release >= 3 +CONSTRUCTOR_STRICT_IS_DEPRECATED = major == 3 and minor == 3 +CONSTRUCTOR_TAKES_CONVERT_CHARREFS = major == 3 and minor >= 4 + + +from bs4.element import ( + CData, + Comment, + Declaration, + Doctype, + ProcessingInstruction, + ) +from bs4.dammit import EntitySubstitution, UnicodeDammit + +from bs4.builder import ( + HTML, + HTMLTreeBuilder, + STRICT, + ) + + +HTMLPARSER = 'html.parser' + +class BeautifulSoupHTMLParser(HTMLParser): + """A subclass of the Python standard library's HTMLParser class, which + listens for HTMLParser events and translates them into calls + to Beautiful Soup's tree construction API. + """ + + # Strategies for handling duplicate attributes + IGNORE = 'ignore' + REPLACE = 'replace' + + def __init__(self, *args, **kwargs): + """Constructor. + + :param on_duplicate_attribute: A strategy for what to do if a + tag includes the same attribute more than once. Accepted + values are: REPLACE (replace earlier values with later + ones, the default), IGNORE (keep the earliest value + encountered), or a callable. A callable must take three + arguments: the dictionary of attributes already processed, + the name of the duplicate attribute, and the most recent value + encountered. + """ + self.on_duplicate_attribute = kwargs.pop( + 'on_duplicate_attribute', self.REPLACE + ) + HTMLParser.__init__(self, *args, **kwargs) + + # Keep a list of empty-element tags that were encountered + # without an explicit closing tag. If we encounter a closing tag + # of this type, we'll associate it with one of those entries. + # + # This isn't a stack because we don't care about the + # order. It's a list of closing tags we've already handled and + # will ignore, assuming they ever show up. + self.already_closed_empty_element = [] + + def error(self, msg): + """In Python 3, HTMLParser subclasses must implement error(), although + this requirement doesn't appear to be documented. + + In Python 2, HTMLParser implements error() by raising an exception, + which we don't want to do. + + In any event, this method is called only on very strange + markup and our best strategy is to pretend it didn't happen + and keep going. + """ + warnings.warn(msg) + + def handle_startendtag(self, name, attrs): + """Handle an incoming empty-element tag. + + This is only called when the markup looks like <tag/>. + + :param name: Name of the tag. + :param attrs: Dictionary of the tag's attributes. + """ + # is_startend() tells handle_starttag not to close the tag + # just because its name matches a known empty-element tag. We + # know that this is an empty-element tag and we want to call + # handle_endtag ourselves. + tag = self.handle_starttag(name, attrs, handle_empty_element=False) + self.handle_endtag(name) + + def handle_starttag(self, name, attrs, handle_empty_element=True): + """Handle an opening tag, e.g. '<tag>' + + :param name: Name of the tag. + :param attrs: Dictionary of the tag's attributes. + :param handle_empty_element: True if this tag is known to be + an empty-element tag (i.e. there is not expected to be any + closing tag). + """ + # XXX namespace + attr_dict = {} + for key, value in attrs: + # Change None attribute values to the empty string + # for consistency with the other tree builders. + if value is None: + value = '' + if key in attr_dict: + # A single attribute shows up multiple times in this + # tag. How to handle it depends on the + # on_duplicate_attribute setting. + on_dupe = self.on_duplicate_attribute + if on_dupe == self.IGNORE: + pass + elif on_dupe in (None, self.REPLACE): + attr_dict[key] = value + else: + on_dupe(attr_dict, key, value) + else: + attr_dict[key] = value + attrvalue = '""' + #print("START", name) + sourceline, sourcepos = self.getpos() + tag = self.soup.handle_starttag( + name, None, None, attr_dict, sourceline=sourceline, + sourcepos=sourcepos + ) + if tag and tag.is_empty_element and handle_empty_element: + # Unlike other parsers, html.parser doesn't send separate end tag + # events for empty-element tags. (It's handled in + # handle_startendtag, but only if the original markup looked like + # <tag/>.) + # + # So we need to call handle_endtag() ourselves. Since we + # know the start event is identical to the end event, we + # don't want handle_endtag() to cross off any previous end + # events for tags of this name. + self.handle_endtag(name, check_already_closed=False) + + # But we might encounter an explicit closing tag for this tag + # later on. If so, we want to ignore it. + self.already_closed_empty_element.append(name) + + def handle_endtag(self, name, check_already_closed=True): + """Handle a closing tag, e.g. '</tag>' + + :param name: A tag name. + :param check_already_closed: True if this tag is expected to + be the closing portion of an empty-element tag, + e.g. '<tag></tag>'. + """ + #print("END", name) + if check_already_closed and name in self.already_closed_empty_element: + # This is a redundant end tag for an empty-element tag. + # We've already called handle_endtag() for it, so just + # check it off the list. + # print("ALREADY CLOSED", name) + self.already_closed_empty_element.remove(name) + else: + self.soup.handle_endtag(name) + + def handle_data(self, data): + """Handle some textual data that shows up between tags.""" + self.soup.handle_data(data) + + def handle_charref(self, name): + """Handle a numeric character reference by converting it to the + corresponding Unicode character and treating it as textual + data. + + :param name: Character number, possibly in hexadecimal. + """ + # XXX workaround for a bug in HTMLParser. Remove this once + # it's fixed in all supported versions. + # http://bugs.python.org/issue13633 + if name.startswith('x'): + real_name = int(name.lstrip('x'), 16) + elif name.startswith('X'): + real_name = int(name.lstrip('X'), 16) + else: + real_name = int(name) + + data = None + if real_name < 256: + # HTML numeric entities are supposed to reference Unicode + # code points, but sometimes they reference code points in + # some other encoding (ahem, Windows-1252). E.g. “ + # instead of É for LEFT DOUBLE QUOTATION MARK. This + # code tries to detect this situation and compensate. + for encoding in (self.soup.original_encoding, 'windows-1252'): + if not encoding: + continue + try: + data = bytearray([real_name]).decode(encoding) + except UnicodeDecodeError as e: + pass + if not data: + try: + data = chr(real_name) + except (ValueError, OverflowError) as e: + pass + data = data or "\N{REPLACEMENT CHARACTER}" + self.handle_data(data) + + def handle_entityref(self, name): + """Handle a named entity reference by converting it to the + corresponding Unicode character and treating it as textual + data. + + :param name: Name of the entity reference. + """ + character = EntitySubstitution.HTML_ENTITY_TO_CHARACTER.get(name) + if character is not None: + data = character + else: + # If this were XML, it would be ambiguous whether "&foo" + # was an character entity reference with a missing + # semicolon or the literal string "&foo". Since this is + # HTML, we have a complete list of all character entity references, + # and this one wasn't found, so assume it's the literal string "&foo". + data = "&%s" % name + self.handle_data(data) + + def handle_comment(self, data): + """Handle an HTML comment. + + :param data: The text of the comment. + """ + self.soup.endData() + self.soup.handle_data(data) + self.soup.endData(Comment) + + def handle_decl(self, data): + """Handle a DOCTYPE declaration. + + :param data: The text of the declaration. + """ + self.soup.endData() + data = data[len("DOCTYPE "):] + self.soup.handle_data(data) + self.soup.endData(Doctype) + + def unknown_decl(self, data): + """Handle a declaration of unknown type -- probably a CDATA block. + + :param data: The text of the declaration. + """ + if data.upper().startswith('CDATA['): + cls = CData + data = data[len('CDATA['):] + else: + cls = Declaration + self.soup.endData() + self.soup.handle_data(data) + self.soup.endData(cls) + + def handle_pi(self, data): + """Handle a processing instruction. + + :param data: The text of the instruction. + """ + self.soup.endData() + self.soup.handle_data(data) + self.soup.endData(ProcessingInstruction) + + +class HTMLParserTreeBuilder(HTMLTreeBuilder): + """A Beautiful soup `TreeBuilder` that uses the `HTMLParser` parser, + found in the Python standard library. + """ + is_xml = False + picklable = True + NAME = HTMLPARSER + features = [NAME, HTML, STRICT] + + # The html.parser knows which line number and position in the + # original file is the source of an element. + TRACKS_LINE_NUMBERS = True + + def __init__(self, parser_args=None, parser_kwargs=None, **kwargs): + """Constructor. + + :param parser_args: Positional arguments to pass into + the BeautifulSoupHTMLParser constructor, once it's + invoked. + :param parser_kwargs: Keyword arguments to pass into + the BeautifulSoupHTMLParser constructor, once it's + invoked. + :param kwargs: Keyword arguments for the superclass constructor. + """ + # Some keyword arguments will be pulled out of kwargs and placed + # into parser_kwargs. + extra_parser_kwargs = dict() + for arg in ('on_duplicate_attribute',): + if arg in kwargs: + value = kwargs.pop(arg) + extra_parser_kwargs[arg] = value + super(HTMLParserTreeBuilder, self).__init__(**kwargs) + parser_args = parser_args or [] + parser_kwargs = parser_kwargs or {} + parser_kwargs.update(extra_parser_kwargs) + if CONSTRUCTOR_TAKES_STRICT and not CONSTRUCTOR_STRICT_IS_DEPRECATED: + parser_kwargs['strict'] = False + if CONSTRUCTOR_TAKES_CONVERT_CHARREFS: + parser_kwargs['convert_charrefs'] = False + self.parser_args = (parser_args, parser_kwargs) + + def prepare_markup(self, markup, user_specified_encoding=None, + document_declared_encoding=None, exclude_encodings=None): + + """Run any preliminary steps necessary to make incoming markup + acceptable to the parser. + + :param markup: Some markup -- probably a bytestring. + :param user_specified_encoding: The user asked to try this encoding. + :param document_declared_encoding: The markup itself claims to be + in this encoding. + :param exclude_encodings: The user asked _not_ to try any of + these encodings. + + :yield: A series of 4-tuples: + (markup, encoding, declared encoding, + has undergone character replacement) + + Each 4-tuple represents a strategy for converting the + document to Unicode and parsing it. Each strategy will be tried + in turn. + """ + if isinstance(markup, str): + # Parse Unicode as-is. + yield (markup, None, None, False) + return + + # Ask UnicodeDammit to sniff the most likely encoding. + try_encodings = [user_specified_encoding, document_declared_encoding] + dammit = UnicodeDammit(markup, try_encodings, is_html=True, + exclude_encodings=exclude_encodings) + yield (dammit.markup, dammit.original_encoding, + dammit.declared_html_encoding, + dammit.contains_replacement_characters) + + def feed(self, markup): + """Run some incoming markup through some parsing process, + populating the `BeautifulSoup` object in self.soup. + """ + args, kwargs = self.parser_args + parser = BeautifulSoupHTMLParser(*args, **kwargs) + parser.soup = self.soup + try: + parser.feed(markup) + parser.close() + except HTMLParseError as e: + warnings.warn(RuntimeWarning( + "Python's built-in HTMLParser cannot parse the given document. This is not a bug in Beautiful Soup. The best solution is to install an external parser (lxml or html5lib), and use Beautiful Soup with that parser. See http://www.crummy.com/software/BeautifulSoup/bs4/doc/#installing-a-parser for help.")) + raise e + parser.already_closed_empty_element = [] + +# Patch 3.2 versions of HTMLParser earlier than 3.2.3 to use some +# 3.2.3 code. This ensures they don't treat markup like <p></p> as a +# string. +# +# XXX This code can be removed once most Python 3 users are on 3.2.3. +if major == 3 and minor == 2 and not CONSTRUCTOR_TAKES_STRICT: + import re + attrfind_tolerant = re.compile( + r'\s*((?<=[\'"\s])[^\s/>][^\s/=>]*)(\s*=+\s*' + r'(\'[^\']*\'|"[^"]*"|(?![\'"])[^>\s]*))?') + HTMLParserTreeBuilder.attrfind_tolerant = attrfind_tolerant + + locatestarttagend = re.compile(r""" + <[a-zA-Z][-.a-zA-Z0-9:_]* # tag name + (?:\s+ # whitespace before attribute name + (?:[a-zA-Z_][-.:a-zA-Z0-9_]* # attribute name + (?:\s*=\s* # value indicator + (?:'[^']*' # LITA-enclosed value + |\"[^\"]*\" # LIT-enclosed value + |[^'\">\s]+ # bare value + ) + )? + ) + )* + \s* # trailing whitespace +""", re.VERBOSE) + BeautifulSoupHTMLParser.locatestarttagend = locatestarttagend + + from html.parser import tagfind, attrfind + + def parse_starttag(self, i): + self.__starttag_text = None + endpos = self.check_for_whole_start_tag(i) + if endpos < 0: + return endpos + rawdata = self.rawdata + self.__starttag_text = rawdata[i:endpos] + + # Now parse the data between i+1 and j into a tag and attrs + attrs = [] + match = tagfind.match(rawdata, i+1) + assert match, 'unexpected call to parse_starttag()' + k = match.end() + self.lasttag = tag = rawdata[i+1:k].lower() + while k < endpos: + if self.strict: + m = attrfind.match(rawdata, k) + else: + m = attrfind_tolerant.match(rawdata, k) + if not m: + break + attrname, rest, attrvalue = m.group(1, 2, 3) + if not rest: + attrvalue = None + elif attrvalue[:1] == '\'' == attrvalue[-1:] or \ + attrvalue[:1] == '"' == attrvalue[-1:]: + attrvalue = attrvalue[1:-1] + if attrvalue: + attrvalue = self.unescape(attrvalue) + attrs.append((attrname.lower(), attrvalue)) + k = m.end() + + end = rawdata[k:endpos].strip() + if end not in (">", "/>"): + lineno, offset = self.getpos() + if "\n" in self.__starttag_text: + lineno = lineno + self.__starttag_text.count("\n") + offset = len(self.__starttag_text) \ + - self.__starttag_text.rfind("\n") + else: + offset = offset + len(self.__starttag_text) + if self.strict: + self.error("junk characters in start tag: %r" + % (rawdata[k:endpos][:20],)) + self.handle_data(rawdata[i:endpos]) + return endpos + if end.endswith('/>'): + # XHTML-style empty tag: <span attr="value" /> + self.handle_startendtag(tag, attrs) + else: + self.handle_starttag(tag, attrs) + if tag in self.CDATA_CONTENT_ELEMENTS: + self.set_cdata_mode(tag) + return endpos + + def set_cdata_mode(self, elem): + self.cdata_elem = elem.lower() + self.interesting = re.compile(r'</\s*%s\s*>' % self.cdata_elem, re.I) + + BeautifulSoupHTMLParser.parse_starttag = parse_starttag + BeautifulSoupHTMLParser.set_cdata_mode = set_cdata_mode + + CONSTRUCTOR_TAKES_STRICT = True