--- a/labs/openlayers/tools/BeautifulSoup.py +++ b/labs/openlayers/tools/BeautifulSoup.py @@ -1,1 +1,1768 @@ - +"""Beautiful Soup +Elixir and Tonic +"The Screen-Scraper's Friend" +http://www.crummy.com/software/BeautifulSoup/ + +Beautiful Soup parses a (possibly invalid) XML or HTML document into a +tree representation. It provides methods and Pythonic idioms that make +it easy to navigate, search, and modify the tree. + +A well-formed XML/HTML document yields a well-formed data +structure. An ill-formed XML/HTML document yields a correspondingly +ill-formed data structure. If your document is only locally +well-formed, you can use this library to find and process the +well-formed part of it. The BeautifulSoup class + +Beautiful Soup works with Python 2.2 and up. It has no external +dependencies, but you'll have more success at converting data to UTF-8 +if you also install these three packages: + +* chardet, for auto-detecting character encodings + http://chardet.feedparser.org/ +* cjkcodecs and iconv_codec, which add more encodings to the ones supported + by stock Python. + http://cjkpython.i18n.org/ + +Beautiful Soup defines classes for two main parsing strategies: + + * BeautifulStoneSoup, for parsing XML, SGML, or your domain-specific + language that kind of looks like XML. + + * BeautifulSoup, for parsing run-of-the-mill HTML code, be it valid + or invalid. This class has web browser-like heuristics for + obtaining a sensible parse tree in the face of common HTML errors. + +Beautiful Soup also defines a class (UnicodeDammit) for autodetecting +the encoding of an HTML or XML document, and converting it to +Unicode. Much of this code is taken from Mark Pilgrim's Universal Feed Parser. + +For more than you ever wanted to know about Beautiful Soup, see the +documentation: +http://www.crummy.com/software/BeautifulSoup/documentation.html + +""" +from __future__ import generators + +__author__ = "Leonard Richardson (leonardr@segfault.org)" +__version__ = "3.0.4" +__copyright__ = "Copyright (c) 2004-2007 Leonard Richardson" +__license__ = "PSF" + +from sgmllib import SGMLParser, SGMLParseError +import codecs +import types +import re +import sgmllib +try: + from htmlentitydefs import name2codepoint +except ImportError: + name2codepoint = {} + +#This hack makes Beautiful Soup able to parse XML with namespaces +sgmllib.tagfind = re.compile('[a-zA-Z][-_.:a-zA-Z0-9]*') + +DEFAULT_OUTPUT_ENCODING = "utf-8" + +# First, the classes that represent markup elements. + +class PageElement: + """Contains the navigational information for some part of the page + (either a tag or a piece of text)""" + + def setup(self, parent=None, previous=None): + """Sets up the initial relations between this element and + other elements.""" + self.parent = parent + self.previous = previous + self.next = None + self.previousSibling = None + self.nextSibling = None + if self.parent and self.parent.contents: + self.previousSibling = self.parent.contents[-1] + self.previousSibling.nextSibling = self + + def replaceWith(self, replaceWith): + oldParent = self.parent + myIndex = self.parent.contents.index(self) + if hasattr(replaceWith, 'parent') and replaceWith.parent == self.parent: + # We're replacing this element with one of its siblings. + index = self.parent.contents.index(replaceWith) + if index and index < myIndex: + # Furthermore, it comes before this element. That + # means that when we extract it, the index of this + # element will change. + myIndex = myIndex - 1 + self.extract() + oldParent.insert(myIndex, replaceWith) + + def extract(self): + """Destructively rips this element out of the tree.""" + if self.parent: + try: + self.parent.contents.remove(self) + except ValueError: + pass + + #Find the two elements that would be next to each other if + #this element (and any children) hadn't been parsed. Connect + #the two. + lastChild = self._lastRecursiveChild() + nextElement = lastChild.next + + if self.previous: + self.previous.next = nextElement + if nextElement: + nextElement.previous = self.previous + self.previous = None + lastChild.next = None + + self.parent = None + if self.previousSibling: + self.previousSibling.nextSibling = self.nextSibling + if self.nextSibling: + self.nextSibling.previousSibling = self.previousSibling + self.previousSibling = self.nextSibling = None + + def _lastRecursiveChild(self): + "Finds the last element beneath this object to be parsed." + lastChild = self + while hasattr(lastChild, 'contents') and lastChild.contents: + lastChild = lastChild.contents[-1] + return lastChild + + def insert(self, position, newChild): + if (isinstance(newChild, basestring) + or isinstance(newChild, unicode)) \ + and not isinstance(newChild, NavigableString): + newChild = NavigableString(newChild) + + position = min(position, len(self.contents)) + if hasattr(newChild, 'parent') and newChild.parent != None: + # We're 'inserting' an element that's already one + # of this object's children. + if newChild.parent == self: + index = self.find(newChild) + if index and index < position: + # Furthermore we're moving it further down the + # list of this object's children. That means that + # when we extract this element, our target index + # will jump down one. + position = position - 1 + newChild.extract() + + newChild.parent = self + previousChild = None + if position == 0: + newChild.previousSibling = None + newChild.previous = self + else: + previousChild = self.contents[position-1] + newChild.previousSibling = previousChild + newChild.previousSibling.nextSibling = newChild + newChild.previous = previousChild._lastRecursiveChild() + if newChild.previous: + newChild.previous.next = newChild + + newChildsLastElement = newChild._lastRecursiveChild() + + if position >= len(self.contents): + newChild.nextSibling = None + + parent = self + parentsNextSibling = None + while not parentsNextSibling: + parentsNextSibling = parent.nextSibling + parent = parent.parent + if not parent: # This is the last element in the document. + break + if parentsNextSibling: + newChildsLastElement.next = parentsNextSibling + else: + newChildsLastElement.next = None + else: + nextChild = self.contents[position] + newChild.nextSibling = nextChild + if newChild.nextSibling: + newChild.nextSibling.previousSibling = newChild + newChildsLastElement.next = nextChild + + if newChildsLastElement.next: + newChildsLastElement.next.previous = newChildsLastElement + self.contents.insert(position, newChild) + + def findNext(self, name=None, attrs={}, text=None, **kwargs): + """Returns the first item that matches the given criteria and + appears after this Tag in the document.""" + return self._findOne(self.findAllNext, name, attrs, text, **kwargs) + + def findAllNext(self, name=None, attrs={}, text=None, limit=None, + **kwargs): + """Returns all items that match the given criteria and appear + before after Tag in the document.""" + return self._findAll(name, attrs, text, limit, self.nextGenerator) + + def findNextSibling(self, name=None, attrs={}, text=None, **kwargs): + """Returns the closest sibling to this Tag that matches the + given criteria and appears after this Tag in the document.""" + return self._findOne(self.findNextSiblings, name, attrs, text, + **kwargs) + + def findNextSiblings(self, name=None, attrs={}, text=None, limit=None, + **kwargs): + """Returns the siblings of this Tag that match the given + criteria and appear after this Tag in the document.""" + return self._findAll(name, attrs, text, limit, + self.nextSiblingGenerator, **kwargs) + fetchNextSiblings = findNextSiblings # Compatibility with pre-3.x + + def findPrevious(self, name=None, attrs={}, text=None, **kwargs): + """Returns the first item that matches the given criteria and + appears before this Tag in the document.""" + return self._findOne(self.findAllPrevious, name, attrs, text, **kwargs) + + def findAllPrevious(self, name=None, attrs={}, text=None, limit=None, + **kwargs): + """Returns all items that match the given criteria and appear + before this Tag in the document.""" + return self._findAll(name, attrs, text, limit, self.previousGenerator, + **kwargs) + fetchPrevious = findAllPrevious # Compatibility with pre-3.x + + def findPreviousSibling(self, name=None, attrs={}, text=None, **kwargs): + """Returns the closest sibling to this Tag that matches the + given criteria and appears before this Tag in the document.""" + return self._findOne(self.findPreviousSiblings, name, attrs, text, + **kwargs) + + def findPreviousSiblings(self, name=None, attrs={}, text=None, + limit=None, **kwargs): + """Returns the siblings of this Tag that match the given + criteria and appear before this Tag in the document.""" + return self._findAll(name, attrs, text, limit, + self.previousSiblingGenerator, **kwargs) + fetchPreviousSiblings = findPreviousSiblings # Compatibility with pre-3.x + + def findParent(self, name=None, attrs={}, **kwargs): + """Returns the closest parent of this Tag that matches the given + criteria.""" + # NOTE: We can't use _findOne because findParents takes a different + # set of arguments. + r = None + l = self.findParents(name, attrs, 1) + if l: + r = l[0] + return r + + def findParents(self, name=None, attrs={}, limit=None, **kwargs): + """Returns the parents of this Tag that match the given + criteria.""" + + return self._findAll(name, attrs, None, limit, self.parentGenerator, + **kwargs) + fetchParents = findParents # Compatibility with pre-3.x + + #These methods do the real heavy lifting. + + def _findOne(self, method, name, attrs, text, **kwargs): + r = None + l = method(name, attrs, text, 1, **kwargs) + if l: + r = l[0] + return r + + def _findAll(self, name, attrs, text, limit, generator, **kwargs): + "Iterates over a generator looking for things that match." + + if isinstance(name, SoupStrainer): + strainer = name + else: + # Build a SoupStrainer + strainer = SoupStrainer(name, attrs, text, **kwargs) + results = ResultSet(strainer) + g = generator() + while True: + try: + i = g.next() + except StopIteration: + break + if i: + found = strainer.search(i) + if found: + results.append(found) + if limit and len(results) >= limit: + break + return results + + #These Generators can be used to navigate starting from both + #NavigableStrings and Tags. + def nextGenerator(self): + i = self + while i: + i = i.next + yield i + + def nextSiblingGenerator(self): + i = self + while i: + i = i.nextSibling + yield i + + def previousGenerator(self): + i = self + while i: + i = i.previous + yield i + + def previousSiblingGenerator(self): + i = self + while i: + i = i.previousSibling + yield i + + def parentGenerator(self): + i = self + while i: + i = i.parent + yield i + + # Utility methods + def substituteEncoding(self, str, encoding=None): + encoding = encoding or "utf-8" + return str.replace("%SOUP-ENCODING%", encoding) + + def toEncoding(self, s, encoding=None): + """Encodes an object to a string in some encoding, or to Unicode. + .""" + if isinstance(s, unicode): + if encoding: + s = s.encode(encoding) + elif isinstance(s, str): + if encoding: + s = s.encode(encoding) + else: + s = unicode(s) + else: + if encoding: + s = self.toEncoding(str(s), encoding) + else: + s = unicode(s) + return s + +class NavigableString(unicode, PageElement): + + def __getattr__(self, attr): + """text.string gives you text. This is for backwards + compatibility for Navigable*String, but for CData* it lets you + get the string without the CData wrapper.""" + if attr == 'string': + return self + else: + raise AttributeError, "'%s' object has no attribute '%s'" % (self.__class__.__name__, attr) + + def __unicode__(self): + return self.__str__(None) + + def __str__(self, encoding=DEFAULT_OUTPUT_ENCODING): + if encoding: + return self.encode(encoding) + else: + return self + +class CData(NavigableString): + + def __str__(self, encoding=DEFAULT_OUTPUT_ENCODING): + return "<![CDATA[%s]]>" % NavigableString.__str__(self, encoding) + +class ProcessingInstruction(NavigableString): + def __str__(self, encoding=DEFAULT_OUTPUT_ENCODING): + output = self + if "%SOUP-ENCODING%" in output: + output = self.substituteEncoding(output, encoding) + return "<?%s?>" % self.toEncoding(output, encoding) + +class Comment(NavigableString): + def __str__(self, encoding=DEFAULT_OUTPUT_ENCODING): + return "<!--%s-->" % NavigableString.__str__(self, encoding) + +class Declaration(NavigableString): + def __str__(self, encoding=DEFAULT_OUTPUT_ENCODING): + return "<!%s>" % NavigableString.__str__(self, encoding) + +class Tag(PageElement): + + """Represents a found HTML tag with its attributes and contents.""" + + XML_SPECIAL_CHARS_TO_ENTITIES = { "'" : "squot", + '"' : "quote", + "&" : "amp", + "<" : "lt", + ">" : "gt" } + + def __init__(self, parser, name, attrs=None, parent=None, + previous=None): + "Basic constructor." + + # We don't actually store the parser object: that lets extracted + # chunks be garbage-collected + self.parserClass = parser.__class__ + self.isSelfClosing = parser.isSelfClosingTag(name) + self.name = name + if attrs == None: + attrs = [] + self.attrs = attrs + self.contents = [] + self.setup(parent, previous) + self.hidden = False + self.containsSubstitutions = False + + def get(self, key, default=None): + """Returns the value of the 'key' attribute for the tag, or + the value given for 'default' if it doesn't have that + attribute.""" + return self._getAttrMap().get(key, default) + + def has_key(self, key): + return self._getAttrMap().has_key(key) + + def __getitem__(self, key): + """tag[key] returns the value of the 'key' attribute for the tag, + and throws an exception if it's not there.""" + return self._getAttrMap()[key] + + def __iter__(self): + "Iterating over a tag iterates over its contents." + return iter(self.contents) + + def __len__(self): + "The length of a tag is the length of its list of contents." + return len(self.contents) + + def __contains__(self, x): + return x in self.contents + + def __nonzero__(self): + "A tag is non-None even if it has no contents." + return True + + def __setitem__(self, key, value): + """Setting tag[key] sets the value of the 'key' attribute for the + tag.""" + self._getAttrMap() + self.attrMap[key] = value + found = False + for i in range(0, len(self.attrs)): + if self.attrs[i][0] == key: + self.attrs[i] = (key, value) + found = True + if not found: + self.attrs.append((key, value)) + self._getAttrMap()[key] = value + + def __delitem__(self, key): + "Deleting tag[key] deletes all 'key' attributes for the tag." + for item in self.attrs: + if item[0] == key: + self.attrs.remove(item) + #We don't break because bad HTML can define the same + #attribute multiple times. + self._getAttrMap() + if self.attrMap.has_key(key): + del self.attrMap[key] + + def __call__(self, *args, **kwargs): + """Calling a tag like a function is the same as calling its + findAll() method. Eg. tag('a') returns a list of all the A tags + found within this tag.""" + return apply(self.findAll, args, kwargs) + + def __getattr__(self, tag): + #print "Getattr %s.%s" % (self.__class__, tag) + if len(tag) > 3 and tag.rfind('Tag') == len(tag)-3: + return self.find(tag[:-3]) + elif tag.find('__') != 0: + return self.find(tag) + + def __eq__(self, other): + """Returns true iff this tag has the same name, the same attributes, + and the same contents (recursively) as the given tag. + + NOTE: right now this will return false if two tags have the + same attributes in a different order. Should this be fixed?""" + if not hasattr(other, 'name') or not hasattr(other, 'attrs') or not hasattr(other, 'contents') or self.name != other.name or self.attrs != other.attrs or len(self) != len(other): + return False + for i in range(0, len(self.contents)): + if self.contents[i] != other.contents[i]: + return False + return True + + def __ne__(self, other): + """Returns true iff this tag is not identical to the other tag, + as defined in __eq__.""" + return not self == other + + def __repr__(self, encoding=DEFAULT_OUTPUT_ENCODING): + """Renders this tag as a string.""" + return self.__str__(encoding) + + def __unicode__(self): + return self.__str__(None) + + def __str__(self, encoding=DEFAULT_OUTPUT_ENCODING, + prettyPrint=False, indentLevel=0): + """Returns a string or Unicode representation of this tag and + its contents. To get Unicode, pass None for encoding. + + NOTE: since Python's HTML parser consumes whitespace, this + method is not certain to reproduce the whitespace present in + the original string.""" + + encodedName = self.toEncoding(self.name, encoding) + + attrs = [] + if self.attrs: + for key, val in self.attrs: + fmt = '%s="%s"' + if isString(val): + if self.containsSubstitutions and '%SOUP-ENCODING%' in val: + val = self.substituteEncoding(val, encoding) + + # The attribute value either: + # + # * Contains no embedded double quotes or single quotes. + # No problem: we enclose it in double quotes. + # * Contains embedded single quotes. No problem: + # double quotes work here too. + # * Contains embedded double quotes. No problem: + # we enclose it in single quotes. + # * Embeds both single _and_ double quotes. This + # can't happen naturally, but it can happen if + # you modify an attribute value after parsing + # the document. Now we have a bit of a + # problem. We solve it by enclosing the + # attribute in single quotes, and escaping any + # embedded single quotes to XML entities. + if '"' in val: + fmt = "%s='%s'" + # This can't happen naturally, but it can happen + # if you modify an attribute value after parsing. + if "'" in val: + val = val.replace("'", "&squot;") + + # Now we're okay w/r/t quotes. But the attribute + # value might also contain angle brackets, or + # ampersands that aren't part of entities. We need + # to escape those to XML entities too. + val = re.sub("([<>]|&(?![^\s]+;))", + lambda x: "&" + self.XML_SPECIAL_CHARS_TO_ENTITIES[x.group(0)[0]] + ";", + val) + + attrs.append(fmt % (self.toEncoding(key, encoding), + self.toEncoding(val, encoding))) + close = '' + closeTag = '' + if self.isSelfClosing: + close = ' /' + else: + closeTag = '</%s>' % encodedName + + indentTag, indentContents = 0, 0 + if prettyPrint: + indentTag = indentLevel + space = (' ' * (indentTag-1)) + indentContents = indentTag + 1 + contents = self.renderContents(encoding, prettyPrint, indentContents) + if self.hidden: + s = contents + else: + s = [] + attributeString = '' + if attrs: + attributeString = ' ' + ' '.join(attrs) + if prettyPrint: + s.append(space) + s.append('<%s%s%s>' % (encodedName, attributeString, close)) + if prettyPrint: + s.append("\n") + s.append(contents) + if prettyPrint and contents and contents[-1] != "\n": + s.append("\n") + if prettyPrint and closeTag: + s.append(space) + s.append(closeTag) + if prettyPrint and closeTag and self.nextSibling: + s.append("\n") + s = ''.join(s) + return s + + def prettify(self, encoding=DEFAULT_OUTPUT_ENCODING): + return self.__str__(encoding, True) + + def renderContents(self, encoding=DEFAULT_OUTPUT_ENCODING, + prettyPrint=False, indentLevel=0): + """Renders the contents of this tag as a string in the given + encoding. If encoding is None, returns a Unicode string..""" + s=[] + for c in self: + text = None + if isinstance(c, NavigableString): + text = c.__str__(encoding) + elif isinstance(c, Tag): + s.append(c.__str__(encoding, prettyPrint, indentLevel)) + if text and prettyPrint: + text = text.strip() + if text: + if prettyPrint: + s.append(" " * (indentLevel-1)) + s.append(text) + if prettyPrint: + s.append("\n") + return ''.join(s) + + #Soup methods + + def find(self, name=None, attrs={}, recursive=True, text=None, + **kwargs): + """Return only the first child of this Tag matching the given + criteria.""" + r = None + l = self.findAll(name, attrs, recursive, text, 1, **kwargs) + if l: + r = l[0] + return r + findChild = find + + def findAll(self, name=None, attrs={}, recursive=True, text=None, + limit=None, **kwargs): + """Extracts a list of Tag objects that match the given + criteria. You can specify the name of the Tag and any + attributes you want the Tag to have. + + The value of a key-value pair in the 'attrs' map can be a + string, a list of strings, a regular expression object, or a + callable that takes a string and returns whether or not the + string matches for some custom definition of 'matches'. The + same is true of the tag name.""" + generator = self.recursiveChildGenerator + if not recursive: + generator = self.childGenerator + return self._findAll(name, attrs, text, limit, generator, **kwargs) + findChildren = findAll + + # Pre-3.x compatibility methods + first = find + fetch = findAll + + def fetchText(self, text=None, recursive=True, limit=None): + return self.findAll(text=text, recursive=recursive, limit=limit) + + def firstText(self, text=None, recursive=True): + return self.find(text=text, recursive=recursive) + + #Utility methods + + def append(self, tag): + """Appends the given tag to the contents of this tag.""" + self.contents.append(tag) + + #Private methods + + def _getAttrMap(self): + """Initializes a map representation of this tag's attributes, + if not already initialized.""" + if not getattr(self, 'attrMap'): + self.attrMap = {} + for (key, value) in self.attrs: + self.attrMap[key] = value + return self.attrMap + + #Generator methods + def childGenerator(self): + for i in range(0, len(self.contents)): + yield self.contents[i] + raise StopIteration + + def recursiveChildGenerator(self): + stack = [(self, 0)] + while stack: + tag, start = stack.pop() + if isinstance(tag, Tag): + for i in range(start, len(tag.contents)): + a = tag.contents[i] + yield a + if isinstance(a, Tag) and tag.contents: + if i < len(tag.contents) - 1: + stack.append((tag, i+1)) + stack.append((a, 0)) + break + raise StopIteration + +# Next, a couple classes to represent queries and their results. +class SoupStrainer: + """Encapsulates a number of ways of matching a markup element (tag or + text).""" + + def __init__(self, name=None, attrs={}, text=None, **kwargs): + self.name = name + if isString(attrs): + kwargs['class'] = attrs + attrs = None + if kwargs: + if attrs: + attrs = attrs.copy() + attrs.update(kwargs) + else: + attrs = kwargs + self.attrs = attrs + self.text = text + + def __str__(self): + if self.text: + return self.text + else: + return "%s|%s" % (self.name, self.attrs) + + def searchTag(self, markupName=None, markupAttrs={}): + found = None + markup = None + if isinstance(markupName, Tag): + markup = markupName + markupAttrs = markup + callFunctionWithTagData = callable(self.name) \ + and not isinstance(markupName, Tag) + + if (not self.name) \ + or callFunctionWithTagData \ + or (markup and self._matches(markup, self.name)) \ + or (not markup and self._matches(markupName, self.name)): + if callFunctionWithTagData: + match = self.name(markupName, markupAttrs) + else: + match = True + markupAttrMap = None + for attr, matchAgainst in self.attrs.items(): + if not markupAttrMap: + if hasattr(markupAttrs, 'get'): + markupAttrMap = markupAttrs + else: + markupAttrMap = {} + for k,v in markupAttrs: + markupAttrMap[k] = v + attrValue = markupAttrMap.get(attr) + if not self._matches(attrValue, matchAgainst): + match = False + break + if match: + if markup: + found = markup + else: + found = markupName + return found + + def search(self, markup): + #print 'looking for %s in %s' % (self, markup) + found = None + # If given a list of items, scan it for a text element that + # matches. + if isList(markup) and not isinstance(markup, Tag): + for element in markup: + if isinstance(element, NavigableString) \ + and self.search(element): + found = element + break + # If it's a Tag, make sure its name or attributes match. + # Don't bother with Tags if we're searching for text. + elif isinstance(markup, Tag): + if not self.text: + found = self.searchTag(markup) + # If it's text, make sure the text matches. + elif isinstance(markup, NavigableString) or \ + isString(markup): + if self._matches(markup, self.text): + found = markup + else: + raise Exception, "I don't know how to match against a %s" \ + % markup.__class__ + return found + + def _matches(self, markup, matchAgainst): + #print "Matching %s against %s" % (markup, matchAgainst) + result = False + if matchAgainst == True and type(matchAgainst) == types.BooleanType: + result = markup != None + elif callable(matchAgainst): + result = matchAgainst(markup) + else: + #Custom match methods take the tag as an argument, but all + #other ways of matching match the tag name as a string. + if isinstance(markup, Tag): + markup = markup.name + if markup and not isString(markup): + markup = unicode(markup) + #Now we know that chunk is either a string, or None. + if hasattr(matchAgainst, 'match'): + # It's a regexp object. + result = markup and matchAgainst.search(markup) + elif isList(matchAgainst): + result = markup in matchAgainst + elif hasattr(matchAgainst, 'items'): + result = markup.has_key(matchAgainst) + elif matchAgainst and isString(markup): + if isinstance(markup, unicode):