Mercurial > repos > shellac > sam_consensus_v3
diff env/lib/python3.9/site-packages/bs4/element.py @ 0:4f3585e2f14b draft default tip
"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"
| author | shellac |
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| date | Mon, 22 Mar 2021 18:12:50 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/env/lib/python3.9/site-packages/bs4/element.py Mon Mar 22 18:12:50 2021 +0000 @@ -0,0 +1,2175 @@ +# Use of this source code is governed by the MIT license. +__license__ = "MIT" + +try: + from collections.abc import Callable # Python 3.6 +except ImportError as e: + from collections import Callable +import re +import sys +import warnings +try: + import soupsieve +except ImportError as e: + soupsieve = None + warnings.warn( + 'The soupsieve package is not installed. CSS selectors cannot be used.' + ) + +from bs4.formatter import ( + Formatter, + HTMLFormatter, + XMLFormatter, +) + +DEFAULT_OUTPUT_ENCODING = "utf-8" +PY3K = (sys.version_info[0] > 2) + +nonwhitespace_re = re.compile(r"\S+") + +# NOTE: This isn't used as of 4.7.0. I'm leaving it for a little bit on +# the off chance someone imported it for their own use. +whitespace_re = re.compile(r"\s+") + +def _alias(attr): + """Alias one attribute name to another for backward compatibility""" + @property + def alias(self): + return getattr(self, attr) + + @alias.setter + def alias(self): + return setattr(self, attr) + return alias + + +# These encodings are recognized by Python (so PageElement.encode +# could theoretically support them) but XML and HTML don't recognize +# them (so they should not show up in an XML or HTML document as that +# document's encoding). +# +# If an XML document is encoded in one of these encodings, no encoding +# will be mentioned in the XML declaration. If an HTML document is +# encoded in one of these encodings, and the HTML document has a +# <meta> tag that mentions an encoding, the encoding will be given as +# the empty string. +# +# Source: +# https://docs.python.org/3/library/codecs.html#python-specific-encodings +PYTHON_SPECIFIC_ENCODINGS = set([ + "idna", + "mbcs", + "oem", + "palmos", + "punycode", + "raw_unicode_escape", + "undefined", + "unicode_escape", + "raw-unicode-escape", + "unicode-escape", + "string-escape", + "string_escape", +]) + + +class NamespacedAttribute(str): + """A namespaced string (e.g. 'xml:lang') that remembers the namespace + ('xml') and the name ('lang') that were used to create it. + """ + + def __new__(cls, prefix, name=None, namespace=None): + if not name: + # This is the default namespace. Its name "has no value" + # per https://www.w3.org/TR/xml-names/#defaulting + name = None + + if name is None: + obj = str.__new__(cls, prefix) + elif prefix is None: + # Not really namespaced. + obj = str.__new__(cls, name) + else: + obj = str.__new__(cls, prefix + ":" + name) + obj.prefix = prefix + obj.name = name + obj.namespace = namespace + return obj + +class AttributeValueWithCharsetSubstitution(str): + """A stand-in object for a character encoding specified in HTML.""" + +class CharsetMetaAttributeValue(AttributeValueWithCharsetSubstitution): + """A generic stand-in for the value of a meta tag's 'charset' attribute. + + When Beautiful Soup parses the markup '<meta charset="utf8">', the + value of the 'charset' attribute will be one of these objects. + """ + + def __new__(cls, original_value): + obj = str.__new__(cls, original_value) + obj.original_value = original_value + return obj + + def encode(self, encoding): + """When an HTML document is being encoded to a given encoding, the + value of a meta tag's 'charset' is the name of the encoding. + """ + if encoding in PYTHON_SPECIFIC_ENCODINGS: + return '' + return encoding + + +class ContentMetaAttributeValue(AttributeValueWithCharsetSubstitution): + """A generic stand-in for the value of a meta tag's 'content' attribute. + + When Beautiful Soup parses the markup: + <meta http-equiv="content-type" content="text/html; charset=utf8"> + + The value of the 'content' attribute will be one of these objects. + """ + + CHARSET_RE = re.compile(r"((^|;)\s*charset=)([^;]*)", re.M) + + def __new__(cls, original_value): + match = cls.CHARSET_RE.search(original_value) + if match is None: + # No substitution necessary. + return str.__new__(str, original_value) + + obj = str.__new__(cls, original_value) + obj.original_value = original_value + return obj + + def encode(self, encoding): + if encoding in PYTHON_SPECIFIC_ENCODINGS: + return '' + def rewrite(match): + return match.group(1) + encoding + return self.CHARSET_RE.sub(rewrite, self.original_value) + + +class PageElement(object): + """Contains the navigational information for some part of the page: + that is, its current location in the parse tree. + + NavigableString, Tag, etc. are all subclasses of PageElement. + """ + + def setup(self, parent=None, previous_element=None, next_element=None, + previous_sibling=None, next_sibling=None): + """Sets up the initial relations between this element and + other elements. + + :param parent: The parent of this element. + + :param previous_element: The element parsed immediately before + this one. + + :param next_element: The element parsed immediately before + this one. + + :param previous_sibling: The most recently encountered element + on the same level of the parse tree as this one. + + :param previous_sibling: The next element to be encountered + on the same level of the parse tree as this one. + """ + self.parent = parent + + self.previous_element = previous_element + if previous_element is not None: + self.previous_element.next_element = self + + self.next_element = next_element + if self.next_element is not None: + self.next_element.previous_element = self + + self.next_sibling = next_sibling + if self.next_sibling is not None: + self.next_sibling.previous_sibling = self + + if (previous_sibling is None + and self.parent is not None and self.parent.contents): + previous_sibling = self.parent.contents[-1] + + self.previous_sibling = previous_sibling + if previous_sibling is not None: + self.previous_sibling.next_sibling = self + + def format_string(self, s, formatter): + """Format the given string using the given formatter. + + :param s: A string. + :param formatter: A Formatter object, or a string naming one of the standard formatters. + """ + if formatter is None: + return s + if not isinstance(formatter, Formatter): + formatter = self.formatter_for_name(formatter) + output = formatter.substitute(s) + return output + + def formatter_for_name(self, formatter): + """Look up or create a Formatter for the given identifier, + if necessary. + + :param formatter: Can be a Formatter object (used as-is), a + function (used as the entity substitution hook for an + XMLFormatter or HTMLFormatter), or a string (used to look + up an XMLFormatter or HTMLFormatter in the appropriate + registry. + """ + if isinstance(formatter, Formatter): + return formatter + if self._is_xml: + c = XMLFormatter + else: + c = HTMLFormatter + if isinstance(formatter, Callable): + return c(entity_substitution=formatter) + return c.REGISTRY[formatter] + + @property + def _is_xml(self): + """Is this element part of an XML tree or an HTML tree? + + This is used in formatter_for_name, when deciding whether an + XMLFormatter or HTMLFormatter is more appropriate. It can be + inefficient, but it should be called very rarely. + """ + if self.known_xml is not None: + # Most of the time we will have determined this when the + # document is parsed. + return self.known_xml + + # Otherwise, it's likely that this element was created by + # direct invocation of the constructor from within the user's + # Python code. + if self.parent is None: + # This is the top-level object. It should have .known_xml set + # from tree creation. If not, take a guess--BS is usually + # used on HTML markup. + return getattr(self, 'is_xml', False) + return self.parent._is_xml + + nextSibling = _alias("next_sibling") # BS3 + previousSibling = _alias("previous_sibling") # BS3 + + def replace_with(self, replace_with): + """Replace this PageElement with another one, keeping the rest of the + tree the same. + + :param replace_with: A PageElement. + :return: `self`, no longer part of the tree. + """ + if self.parent is None: + raise ValueError( + "Cannot replace one element with another when the " + "element to be replaced is not part of a tree.") + if replace_with is self: + return + if replace_with is self.parent: + raise ValueError("Cannot replace a Tag with its parent.") + old_parent = self.parent + my_index = self.parent.index(self) + self.extract(_self_index=my_index) + old_parent.insert(my_index, replace_with) + return self + replaceWith = replace_with # BS3 + + def unwrap(self): + """Replace this PageElement with its contents. + + :return: `self`, no longer part of the tree. + """ + my_parent = self.parent + if self.parent is None: + raise ValueError( + "Cannot replace an element with its contents when that" + "element is not part of a tree.") + my_index = self.parent.index(self) + self.extract(_self_index=my_index) + for child in reversed(self.contents[:]): + my_parent.insert(my_index, child) + return self + replace_with_children = unwrap + replaceWithChildren = unwrap # BS3 + + def wrap(self, wrap_inside): + """Wrap this PageElement inside another one. + + :param wrap_inside: A PageElement. + :return: `wrap_inside`, occupying the position in the tree that used + to be occupied by `self`, and with `self` inside it. + """ + me = self.replace_with(wrap_inside) + wrap_inside.append(me) + return wrap_inside + + def extract(self, _self_index=None): + """Destructively rips this element out of the tree. + + :param _self_index: The location of this element in its parent's + .contents, if known. Passing this in allows for a performance + optimization. + + :return: `self`, no longer part of the tree. + """ + if self.parent is not None: + if _self_index is None: + _self_index = self.parent.index(self) + del self.parent.contents[_self_index] + + #Find the two elements that would be next to each other if + #this element (and any children) hadn't been parsed. Connect + #the two. + last_child = self._last_descendant() + next_element = last_child.next_element + + if (self.previous_element is not None and + self.previous_element is not next_element): + self.previous_element.next_element = next_element + if next_element is not None and next_element is not self.previous_element: + next_element.previous_element = self.previous_element + self.previous_element = None + last_child.next_element = None + + self.parent = None + if (self.previous_sibling is not None + and self.previous_sibling is not self.next_sibling): + self.previous_sibling.next_sibling = self.next_sibling + if (self.next_sibling is not None + and self.next_sibling is not self.previous_sibling): + self.next_sibling.previous_sibling = self.previous_sibling + self.previous_sibling = self.next_sibling = None + return self + + def _last_descendant(self, is_initialized=True, accept_self=True): + """Finds the last element beneath this object to be parsed. + + :param is_initialized: Has `setup` been called on this PageElement + yet? + :param accept_self: Is `self` an acceptable answer to the question? + """ + if is_initialized and self.next_sibling is not None: + last_child = self.next_sibling.previous_element + else: + last_child = self + while isinstance(last_child, Tag) and last_child.contents: + last_child = last_child.contents[-1] + if not accept_self and last_child is self: + last_child = None + return last_child + # BS3: Not part of the API! + _lastRecursiveChild = _last_descendant + + def insert(self, position, new_child): + """Insert a new PageElement in the list of this PageElement's children. + + This works the same way as `list.insert`. + + :param position: The numeric position that should be occupied + in `self.children` by the new PageElement. + :param new_child: A PageElement. + """ + if new_child is None: + raise ValueError("Cannot insert None into a tag.") + if new_child is self: + raise ValueError("Cannot insert a tag into itself.") + if (isinstance(new_child, str) + and not isinstance(new_child, NavigableString)): + new_child = NavigableString(new_child) + + from bs4 import BeautifulSoup + if isinstance(new_child, BeautifulSoup): + # We don't want to end up with a situation where one BeautifulSoup + # object contains another. Insert the children one at a time. + for subchild in list(new_child.contents): + self.insert(position, subchild) + position += 1 + return + position = min(position, len(self.contents)) + if hasattr(new_child, 'parent') and new_child.parent is not None: + # We're 'inserting' an element that's already one + # of this object's children. + if new_child.parent is self: + current_index = self.index(new_child) + if current_index < position: + # We're moving this element 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 -= 1 + new_child.extract() + + new_child.parent = self + previous_child = None + if position == 0: + new_child.previous_sibling = None + new_child.previous_element = self + else: + previous_child = self.contents[position - 1] + new_child.previous_sibling = previous_child + new_child.previous_sibling.next_sibling = new_child + new_child.previous_element = previous_child._last_descendant(False) + if new_child.previous_element is not None: + new_child.previous_element.next_element = new_child + + new_childs_last_element = new_child._last_descendant(False) + + if position >= len(self.contents): + new_child.next_sibling = None + + parent = self + parents_next_sibling = None + while parents_next_sibling is None and parent is not None: + parents_next_sibling = parent.next_sibling + parent = parent.parent + if parents_next_sibling is not None: + # We found the element that comes next in the document. + break + if parents_next_sibling is not None: + new_childs_last_element.next_element = parents_next_sibling + else: + # The last element of this tag is the last element in + # the document. + new_childs_last_element.next_element = None + else: + next_child = self.contents[position] + new_child.next_sibling = next_child + if new_child.next_sibling is not None: + new_child.next_sibling.previous_sibling = new_child + new_childs_last_element.next_element = next_child + + if new_childs_last_element.next_element is not None: + new_childs_last_element.next_element.previous_element = new_childs_last_element + self.contents.insert(position, new_child) + + def append(self, tag): + """Appends the given PageElement to the contents of this one. + + :param tag: A PageElement. + """ + self.insert(len(self.contents), tag) + + def extend(self, tags): + """Appends the given PageElements to this one's contents. + + :param tags: A list of PageElements. + """ + if isinstance(tags, Tag): + # Calling self.append() on another tag's contents will change + # the list we're iterating over. Make a list that won't + # change. + tags = list(tags.contents) + for tag in tags: + self.append(tag) + + def insert_before(self, *args): + """Makes the given element(s) the immediate predecessor of this one. + + All the elements will have the same parent, and the given elements + will be immediately before this one. + + :param args: One or more PageElements. + """ + parent = self.parent + if parent is None: + raise ValueError( + "Element has no parent, so 'before' has no meaning.") + if any(x is self for x in args): + raise ValueError("Can't insert an element before itself.") + for predecessor in args: + # Extract first so that the index won't be screwed up if they + # are siblings. + if isinstance(predecessor, PageElement): + predecessor.extract() + index = parent.index(self) + parent.insert(index, predecessor) + + def insert_after(self, *args): + """Makes the given element(s) the immediate successor of this one. + + The elements will have the same parent, and the given elements + will be immediately after this one. + + :param args: One or more PageElements. + """ + # Do all error checking before modifying the tree. + parent = self.parent + if parent is None: + raise ValueError( + "Element has no parent, so 'after' has no meaning.") + if any(x is self for x in args): + raise ValueError("Can't insert an element after itself.") + + offset = 0 + for successor in args: + # Extract first so that the index won't be screwed up if they + # are siblings. + if isinstance(successor, PageElement): + successor.extract() + index = parent.index(self) + parent.insert(index+1+offset, successor) + offset += 1 + + def find_next(self, name=None, attrs={}, text=None, **kwargs): + """Find the first PageElement that matches the given criteria and + appears later in the document than this PageElement. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :kwargs: A dictionary of filters on attribute values. + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + return self._find_one(self.find_all_next, name, attrs, text, **kwargs) + findNext = find_next # BS3 + + def find_all_next(self, name=None, attrs={}, text=None, limit=None, + **kwargs): + """Find all PageElements that match the given criteria and appear + later in the document than this PageElement. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :param limit: Stop looking after finding this many results. + :kwargs: A dictionary of filters on attribute values. + :return: A ResultSet containing PageElements. + """ + return self._find_all(name, attrs, text, limit, self.next_elements, + **kwargs) + findAllNext = find_all_next # BS3 + + def find_next_sibling(self, name=None, attrs={}, text=None, **kwargs): + """Find the closest sibling to this PageElement that matches the + given criteria and appears later in the document. + + All find_* methods take a common set of arguments. See the + online documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :kwargs: A dictionary of filters on attribute values. + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + return self._find_one(self.find_next_siblings, name, attrs, text, + **kwargs) + findNextSibling = find_next_sibling # BS3 + + def find_next_siblings(self, name=None, attrs={}, text=None, limit=None, + **kwargs): + """Find all siblings of this PageElement that match the given criteria + and appear later in the document. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :param limit: Stop looking after finding this many results. + :kwargs: A dictionary of filters on attribute values. + :return: A ResultSet of PageElements. + :rtype: bs4.element.ResultSet + """ + return self._find_all(name, attrs, text, limit, + self.next_siblings, **kwargs) + findNextSiblings = find_next_siblings # BS3 + fetchNextSiblings = find_next_siblings # BS2 + + def find_previous(self, name=None, attrs={}, text=None, **kwargs): + """Look backwards in the document from this PageElement and find the + first PageElement that matches the given criteria. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :kwargs: A dictionary of filters on attribute values. + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + return self._find_one( + self.find_all_previous, name, attrs, text, **kwargs) + findPrevious = find_previous # BS3 + + def find_all_previous(self, name=None, attrs={}, text=None, limit=None, + **kwargs): + """Look backwards in the document from this PageElement and find all + PageElements that match the given criteria. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :param limit: Stop looking after finding this many results. + :kwargs: A dictionary of filters on attribute values. + :return: A ResultSet of PageElements. + :rtype: bs4.element.ResultSet + """ + return self._find_all(name, attrs, text, limit, self.previous_elements, + **kwargs) + findAllPrevious = find_all_previous # BS3 + fetchPrevious = find_all_previous # BS2 + + def find_previous_sibling(self, name=None, attrs={}, text=None, **kwargs): + """Returns the closest sibling to this PageElement that matches the + given criteria and appears earlier in the document. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :kwargs: A dictionary of filters on attribute values. + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + return self._find_one(self.find_previous_siblings, name, attrs, text, + **kwargs) + findPreviousSibling = find_previous_sibling # BS3 + + def find_previous_siblings(self, name=None, attrs={}, text=None, + limit=None, **kwargs): + """Returns all siblings to this PageElement that match the + given criteria and appear earlier in the document. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :param limit: Stop looking after finding this many results. + :kwargs: A dictionary of filters on attribute values. + :return: A ResultSet of PageElements. + :rtype: bs4.element.ResultSet + """ + return self._find_all(name, attrs, text, limit, + self.previous_siblings, **kwargs) + findPreviousSiblings = find_previous_siblings # BS3 + fetchPreviousSiblings = find_previous_siblings # BS2 + + def find_parent(self, name=None, attrs={}, **kwargs): + """Find the closest parent of this PageElement that matches the given + criteria. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :kwargs: A dictionary of filters on attribute values. + + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + # NOTE: We can't use _find_one because findParents takes a different + # set of arguments. + r = None + l = self.find_parents(name, attrs, 1, **kwargs) + if l: + r = l[0] + return r + findParent = find_parent # BS3 + + def find_parents(self, name=None, attrs={}, limit=None, **kwargs): + """Find all parents of this PageElement that match the given criteria. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param limit: Stop looking after finding this many results. + :kwargs: A dictionary of filters on attribute values. + + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + return self._find_all(name, attrs, None, limit, self.parents, + **kwargs) + findParents = find_parents # BS3 + fetchParents = find_parents # BS2 + + @property + def next(self): + """The PageElement, if any, that was parsed just after this one. + + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + return self.next_element + + @property + def previous(self): + """The PageElement, if any, that was parsed just before this one. + + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + return self.previous_element + + #These methods do the real heavy lifting. + + def _find_one(self, method, name, attrs, text, **kwargs): + r = None + l = method(name, attrs, text, 1, **kwargs) + if l: + r = l[0] + return r + + def _find_all(self, name, attrs, text, limit, generator, **kwargs): + "Iterates over a generator looking for things that match." + + if text is None and 'string' in kwargs: + text = kwargs['string'] + del kwargs['string'] + + if isinstance(name, SoupStrainer): + strainer = name + else: + strainer = SoupStrainer(name, attrs, text, **kwargs) + + if text is None and not limit and not attrs and not kwargs: + if name is True or name is None: + # Optimization to find all tags. + result = (element for element in generator + if isinstance(element, Tag)) + return ResultSet(strainer, result) + elif isinstance(name, str): + # Optimization to find all tags with a given name. + if name.count(':') == 1: + # This is a name with a prefix. If this is a namespace-aware document, + # we need to match the local name against tag.name. If not, + # we need to match the fully-qualified name against tag.name. + prefix, local_name = name.split(':', 1) + else: + prefix = None + local_name = name + result = (element for element in generator + if isinstance(element, Tag) + and ( + element.name == name + ) or ( + element.name == local_name + and (prefix is None or element.prefix == prefix) + ) + ) + return ResultSet(strainer, result) + results = ResultSet(strainer) + while True: + try: + i = next(generator) + 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. + @property + def next_elements(self): + """All PageElements that were parsed after this one. + + :yield: A sequence of PageElements. + """ + i = self.next_element + while i is not None: + yield i + i = i.next_element + + @property + def next_siblings(self): + """All PageElements that are siblings of this one but were parsed + later. + + :yield: A sequence of PageElements. + """ + i = self.next_sibling + while i is not None: + yield i + i = i.next_sibling + + @property + def previous_elements(self): + """All PageElements that were parsed before this one. + + :yield: A sequence of PageElements. + """ + i = self.previous_element + while i is not None: + yield i + i = i.previous_element + + @property + def previous_siblings(self): + """All PageElements that are siblings of this one but were parsed + earlier. + + :yield: A sequence of PageElements. + """ + i = self.previous_sibling + while i is not None: + yield i + i = i.previous_sibling + + @property + def parents(self): + """All PageElements that are parents of this PageElement. + + :yield: A sequence of PageElements. + """ + i = self.parent + while i is not None: + yield i + i = i.parent + + @property + def decomposed(self): + """Check whether a PageElement has been decomposed. + + :rtype: bool + """ + return getattr(self, '_decomposed', False) or False + + # Old non-property versions of the generators, for backwards + # compatibility with BS3. + def nextGenerator(self): + return self.next_elements + + def nextSiblingGenerator(self): + return self.next_siblings + + def previousGenerator(self): + return self.previous_elements + + def previousSiblingGenerator(self): + return self.previous_siblings + + def parentGenerator(self): + return self.parents + + +class NavigableString(str, PageElement): + """A Python Unicode string that is part of a parse tree. + + When Beautiful Soup parses the markup <b>penguin</b>, it will + create a NavigableString for the string "penguin". + """ + + PREFIX = '' + SUFFIX = '' + + # We can't tell just by looking at a string whether it's contained + # in an XML document or an HTML document. + + known_xml = None + + def __new__(cls, value): + """Create a new NavigableString. + + When unpickling a NavigableString, this method is called with + the string in DEFAULT_OUTPUT_ENCODING. That encoding needs to be + passed in to the superclass's __new__ or the superclass won't know + how to handle non-ASCII characters. + """ + if isinstance(value, str): + u = str.__new__(cls, value) + else: + u = str.__new__(cls, value, DEFAULT_OUTPUT_ENCODING) + u.setup() + return u + + def __copy__(self): + """A copy of a NavigableString has the same contents and class + as the original, but it is not connected to the parse tree. + """ + return type(self)(self) + + def __getnewargs__(self): + return (str(self),) + + 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 output_ready(self, formatter="minimal"): + """Run the string through the provided formatter. + + :param formatter: A Formatter object, or a string naming one of the standard formatters. + """ + output = self.format_string(self, formatter) + return self.PREFIX + output + self.SUFFIX + + @property + def name(self): + """Since a NavigableString is not a Tag, it has no .name. + + This property is implemented so that code like this doesn't crash + when run on a mixture of Tag and NavigableString objects: + [x.name for x in tag.children] + """ + return None + + @name.setter + def name(self, name): + """Prevent NavigableString.name from ever being set.""" + raise AttributeError("A NavigableString cannot be given a name.") + + +class PreformattedString(NavigableString): + """A NavigableString not subject to the normal formatting rules. + + This is an abstract class used for special kinds of strings such + as comments (the Comment class) and CDATA blocks (the CData + class). + """ + + PREFIX = '' + SUFFIX = '' + + def output_ready(self, formatter=None): + """Make this string ready for output by adding any subclass-specific + prefix or suffix. + + :param formatter: A Formatter object, or a string naming one + of the standard formatters. The string will be passed into the + Formatter, but only to trigger any side effects: the return + value is ignored. + + :return: The string, with any subclass-specific prefix and + suffix added on. + """ + if formatter is not None: + ignore = self.format_string(self, formatter) + return self.PREFIX + self + self.SUFFIX + +class CData(PreformattedString): + """A CDATA block.""" + PREFIX = '<![CDATA[' + SUFFIX = ']]>' + +class ProcessingInstruction(PreformattedString): + """A SGML processing instruction.""" + + PREFIX = '<?' + SUFFIX = '>' + +class XMLProcessingInstruction(ProcessingInstruction): + """An XML processing instruction.""" + PREFIX = '<?' + SUFFIX = '?>' + +class Comment(PreformattedString): + """An HTML or XML comment.""" + PREFIX = '<!--' + SUFFIX = '-->' + + +class Declaration(PreformattedString): + """An XML declaration.""" + PREFIX = '<?' + SUFFIX = '?>' + + +class Doctype(PreformattedString): + """A document type declaration.""" + @classmethod + def for_name_and_ids(cls, name, pub_id, system_id): + """Generate an appropriate document type declaration for a given + public ID and system ID. + + :param name: The name of the document's root element, e.g. 'html'. + :param pub_id: The Formal Public Identifier for this document type, + e.g. '-//W3C//DTD XHTML 1.1//EN' + :param system_id: The system identifier for this document type, + e.g. 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd' + + :return: A Doctype. + """ + value = name or '' + if pub_id is not None: + value += ' PUBLIC "%s"' % pub_id + if system_id is not None: + value += ' "%s"' % system_id + elif system_id is not None: + value += ' SYSTEM "%s"' % system_id + + return Doctype(value) + + PREFIX = '<!DOCTYPE ' + SUFFIX = '>\n' + + +class Stylesheet(NavigableString): + """A NavigableString representing an stylesheet (probably + CSS). + + Used to distinguish embedded stylesheets from textual content. + """ + pass + + +class Script(NavigableString): + """A NavigableString representing an executable script (probably + Javascript). + + Used to distinguish executable code from textual content. + """ + pass + + +class TemplateString(NavigableString): + """A NavigableString representing a string found inside an HTML + template embedded in a larger document. + + Used to distinguish such strings from the main body of the document. + """ + pass + + +class Tag(PageElement): + """Represents an HTML or XML tag that is part of a parse tree, along + with its attributes and contents. + + When Beautiful Soup parses the markup <b>penguin</b>, it will + create a Tag object representing the <b> tag. + """ + + def __init__(self, parser=None, builder=None, name=None, namespace=None, + prefix=None, attrs=None, parent=None, previous=None, + is_xml=None, sourceline=None, sourcepos=None, + can_be_empty_element=None, cdata_list_attributes=None, + preserve_whitespace_tags=None + ): + """Basic constructor. + + :param parser: A BeautifulSoup object. + :param builder: A TreeBuilder. + :param name: The name of the tag. + :param namespace: The URI of this Tag's XML namespace, if any. + :param prefix: The prefix for this Tag's XML namespace, if any. + :param attrs: A dictionary of this Tag's attribute values. + :param parent: The PageElement to use as this Tag's parent. + :param previous: The PageElement that was parsed immediately before + this tag. + :param is_xml: If True, this is an XML tag. Otherwise, this is an + HTML tag. + :param sourceline: The line number where this tag was found in its + source document. + :param sourcepos: The character position within `sourceline` where this + tag was found. + :param can_be_empty_element: If True, this tag should be + represented as <tag/>. If False, this tag should be represented + as <tag></tag>. + :param cdata_list_attributes: A list of attributes whose values should + be treated as CDATA if they ever show up on this tag. + :param preserve_whitespace_tags: A list of tag names whose contents + should have their whitespace preserved. + """ + if parser is None: + self.parser_class = None + else: + # We don't actually store the parser object: that lets extracted + # chunks be garbage-collected. + self.parser_class = parser.__class__ + if name is None: + raise ValueError("No value provided for new tag's name.") + self.name = name + self.namespace = namespace + self.prefix = prefix + if ((not builder or builder.store_line_numbers) + and (sourceline is not None or sourcepos is not None)): + self.sourceline = sourceline + self.sourcepos = sourcepos + if attrs is None: + attrs = {} + elif attrs: + if builder is not None and builder.cdata_list_attributes: + attrs = builder._replace_cdata_list_attribute_values( + self.name, attrs) + else: + attrs = dict(attrs) + else: + attrs = dict(attrs) + + # If possible, determine ahead of time whether this tag is an + # XML tag. + if builder: + self.known_xml = builder.is_xml + else: + self.known_xml = is_xml + self.attrs = attrs + self.contents = [] + self.setup(parent, previous) + self.hidden = False + + if builder is None: + # In the absence of a TreeBuilder, use whatever values were + # passed in here. They're probably None, unless this is a copy of some + # other tag. + self.can_be_empty_element = can_be_empty_element + self.cdata_list_attributes = cdata_list_attributes + self.preserve_whitespace_tags = preserve_whitespace_tags + else: + # Set up any substitutions for this tag, such as the charset in a META tag. + builder.set_up_substitutions(self) + + # Ask the TreeBuilder whether this tag might be an empty-element tag. + self.can_be_empty_element = builder.can_be_empty_element(name) + + # Keep track of the list of attributes of this tag that + # might need to be treated as a list. + # + # For performance reasons, we store the whole data structure + # rather than asking the question of every tag. Asking would + # require building a new data structure every time, and + # (unlike can_be_empty_element), we almost never need + # to check this. + self.cdata_list_attributes = builder.cdata_list_attributes + + # Keep track of the names that might cause this tag to be treated as a + # whitespace-preserved tag. + self.preserve_whitespace_tags = builder.preserve_whitespace_tags + + parserClass = _alias("parser_class") # BS3 + + def __copy__(self): + """A copy of a Tag is a new Tag, unconnected to the parse tree. + Its contents are a copy of the old Tag's contents. + """ + clone = type(self)( + None, self.builder, self.name, self.namespace, + self.prefix, self.attrs, is_xml=self._is_xml, + sourceline=self.sourceline, sourcepos=self.sourcepos, + can_be_empty_element=self.can_be_empty_element, + cdata_list_attributes=self.cdata_list_attributes, + preserve_whitespace_tags=self.preserve_whitespace_tags + ) + for attr in ('can_be_empty_element', 'hidden'): + setattr(clone, attr, getattr(self, attr)) + for child in self.contents: + clone.append(child.__copy__()) + return clone + + @property + def is_empty_element(self): + """Is this tag an empty-element tag? (aka a self-closing tag) + + A tag that has contents is never an empty-element tag. + + A tag that has no contents may or may not be an empty-element + tag. It depends on the builder used to create the tag. If the + builder has a designated list of empty-element tags, then only + a tag whose name shows up in that list is considered an + empty-element tag. + + If the builder has no designated list of empty-element tags, + then any tag with no contents is an empty-element tag. + """ + return len(self.contents) == 0 and self.can_be_empty_element + isSelfClosing = is_empty_element # BS3 + + @property + def string(self): + """Convenience property to get the single string within this + PageElement. + + TODO It might make sense to have NavigableString.string return + itself. + + :return: If this element has a single string child, return + value is that string. If this element has one child tag, + return value is the 'string' attribute of the child tag, + recursively. If this element is itself a string, has no + children, or has more than one child, return value is None. + """ + if len(self.contents) != 1: + return None + child = self.contents[0] + if isinstance(child, NavigableString): + return child + return child.string + + @string.setter + def string(self, string): + """Replace this PageElement's contents with `string`.""" + self.clear() + self.append(string.__class__(string)) + + def _all_strings(self, strip=False, types=(NavigableString, CData)): + """Yield all strings of certain classes, possibly stripping them. + + :param strip: If True, all strings will be stripped before being + yielded. + + :types: A tuple of NavigableString subclasses. Any strings of + a subclass not found in this list will be ignored. By + default, this means only NavigableString and CData objects + will be considered. So no comments, processing instructions, + etc. + + :yield: A sequence of strings. + """ + for descendant in self.descendants: + if ( + (types is None and not isinstance(descendant, NavigableString)) + or + (types is not None and type(descendant) not in types)): + continue + if strip: + descendant = descendant.strip() + if len(descendant) == 0: + continue + yield descendant + + strings = property(_all_strings) + + @property + def stripped_strings(self): + """Yield all strings in the document, stripping them first. + + :yield: A sequence of stripped strings. + """ + for string in self._all_strings(True): + yield string + + def get_text(self, separator="", strip=False, + types=(NavigableString, CData)): + """Get all child strings, concatenated using the given separator. + + :param separator: Strings will be concatenated using this separator. + + :param strip: If True, strings will be stripped before being + concatenated. + + :types: A tuple of NavigableString subclasses. Any strings of + a subclass not found in this list will be ignored. By + default, this means only NavigableString and CData objects + will be considered. So no comments, processing instructions, + stylesheets, etc. + + :return: A string. + """ + return separator.join([s for s in self._all_strings( + strip, types=types)]) + getText = get_text + text = property(get_text) + + def decompose(self): + """Recursively destroys this PageElement and its children. + + This element will be removed from the tree and wiped out; so + will everything beneath it. + + The behavior of a decomposed PageElement is undefined and you + should never use one for anything, but if you need to _check_ + whether an element has been decomposed, you can use the + `decomposed` property. + """ + self.extract() + i = self + while i is not None: + n = i.next_element + i.__dict__.clear() + i.contents = [] + i._decomposed = True + i = n + + def clear(self, decompose=False): + """Wipe out all children of this PageElement by calling extract() + on them. + + :param decompose: If this is True, decompose() (a more + destructive method) will be called instead of extract(). + """ + if decompose: + for element in self.contents[:]: + if isinstance(element, Tag): + element.decompose() + else: + element.extract() + else: + for element in self.contents[:]: + element.extract() + + def smooth(self): + """Smooth out this element's children by consolidating consecutive + strings. + + This makes pretty-printed output look more natural following a + lot of operations that modified the tree. + """ + # Mark the first position of every pair of children that need + # to be consolidated. Do this rather than making a copy of + # self.contents, since in most cases very few strings will be + # affected. + marked = [] + for i, a in enumerate(self.contents): + if isinstance(a, Tag): + # Recursively smooth children. + a.smooth() + if i == len(self.contents)-1: + # This is the last item in .contents, and it's not a + # tag. There's no chance it needs any work. + continue + b = self.contents[i+1] + if (isinstance(a, NavigableString) + and isinstance(b, NavigableString) + and not isinstance(a, PreformattedString) + and not isinstance(b, PreformattedString) + ): + marked.append(i) + + # Go over the marked positions in reverse order, so that + # removing items from .contents won't affect the remaining + # positions. + for i in reversed(marked): + a = self.contents[i] + b = self.contents[i+1] + b.extract() + n = NavigableString(a+b) + a.replace_with(n) + + def index(self, element): + """Find the index of a child by identity, not value. + + Avoids issues with tag.contents.index(element) getting the + index of equal elements. + + :param element: Look for this PageElement in `self.contents`. + """ + for i, child in enumerate(self.contents): + if child is element: + return i + raise ValueError("Tag.index: element not in tag") + + 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.attrs.get(key, default) + + def get_attribute_list(self, key, default=None): + """The same as get(), but always returns a list. + + :param key: The attribute to look for. + :param default: Use this value if the attribute is not present + on this PageElement. + :return: A list of values, probably containing only a single + value. + """ + value = self.get(key, default) + if not isinstance(value, list): + value = [value] + return value + + def has_attr(self, key): + """Does this PageElement have an attribute with the given name?""" + return key in self.attrs + + def __hash__(self): + return str(self).__hash__() + + 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.attrs[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 __bool__(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.attrs[key] = value + + def __delitem__(self, key): + "Deleting tag[key] deletes all 'key' attributes for the tag." + self.attrs.pop(key, None) + + def __call__(self, *args, **kwargs): + """Calling a Tag like a function is the same as calling its + find_all() method. Eg. tag('a') returns a list of all the A tags + found within this tag.""" + return self.find_all(*args, **kwargs) + + def __getattr__(self, tag): + """Calling tag.subtag is the same as calling tag.find(name="subtag")""" + #print("Getattr %s.%s" % (self.__class__, tag)) + if len(tag) > 3 and tag.endswith('Tag'): + # BS3: soup.aTag -> "soup.find("a") + tag_name = tag[:-3] + warnings.warn( + '.%(name)sTag is deprecated, use .find("%(name)s") instead. If you really were looking for a tag called %(name)sTag, use .find("%(name)sTag")' % dict( + name=tag_name + ) + ) + return self.find(tag_name) + # We special case contents to avoid recursion. + elif not tag.startswith("__") and not tag == "contents": + return self.find(tag) + raise AttributeError( + "'%s' object has no attribute '%s'" % (self.__class__, tag)) + + def __eq__(self, other): + """Returns true iff this Tag has the same name, the same attributes, + and the same contents (recursively) as `other`.""" + if self is other: + return True + 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, my_child in enumerate(self.contents): + if my_child != other.contents[i]: + return False + return True + + def __ne__(self, other): + """Returns true iff this Tag is not identical to `other`, + as defined in __eq__.""" + return not self == other + + def __repr__(self, encoding="unicode-escape"): + """Renders this PageElement as a string. + + :param encoding: The encoding to use (Python 2 only). + :return: Under Python 2, a bytestring; under Python 3, + a Unicode string. + """ + if PY3K: + # "The return value must be a string object", i.e. Unicode + return self.decode() + else: + # "The return value must be a string object", i.e. a bytestring. + # By convention, the return value of __repr__ should also be + # an ASCII string. + return self.encode(encoding) + + def __unicode__(self): + """Renders this PageElement as a Unicode string.""" + return self.decode() + + def __str__(self): + """Renders this PageElement as a generic string. + + :return: Under Python 2, a UTF-8 bytestring; under Python 3, + a Unicode string. + """ + if PY3K: + return self.decode() + else: + return self.encode() + + if PY3K: + __str__ = __repr__ = __unicode__ + + def encode(self, encoding=DEFAULT_OUTPUT_ENCODING, + indent_level=None, formatter="minimal", + errors="xmlcharrefreplace"): + """Render a bytestring representation of this PageElement and its + contents. + + :param encoding: The destination encoding. + :param indent_level: Each line of the rendering will be + indented this many spaces. Used internally in + recursive calls while pretty-printing. + :param formatter: A Formatter object, or a string naming one of + the standard formatters. + :param errors: An error handling strategy such as + 'xmlcharrefreplace'. This value is passed along into + encode() and its value should be one of the constants + defined by Python. + :return: A bytestring. + + """ + # Turn the data structure into Unicode, then encode the + # Unicode. + u = self.decode(indent_level, encoding, formatter) + return u.encode(encoding, errors) + + def decode(self, indent_level=None, + eventual_encoding=DEFAULT_OUTPUT_ENCODING, + formatter="minimal"): + """Render a Unicode representation of this PageElement and its + contents. + + :param indent_level: Each line of the rendering will be + indented this many spaces. Used internally in + recursive calls while pretty-printing. + :param eventual_encoding: The tag is destined to be + encoded into this encoding. This method is _not_ + responsible for performing that encoding. This information + is passed in so that it can be substituted in if the + document contains a <META> tag that mentions the document's + encoding. + :param formatter: A Formatter object, or a string naming one of + the standard formatters. + """ + + # First off, turn a non-Formatter `formatter` into a Formatter + # object. This will stop the lookup from happening over and + # over again. + if not isinstance(formatter, Formatter): + formatter = self.formatter_for_name(formatter) + attributes = formatter.attributes(self) + attrs = [] + for key, val in attributes: + if val is None: + decoded = key + else: + if isinstance(val, list) or isinstance(val, tuple): + val = ' '.join(val) + elif not isinstance(val, str): + val = str(val) + elif ( + isinstance(val, AttributeValueWithCharsetSubstitution) + and eventual_encoding is not None + ): + val = val.encode(eventual_encoding) + + text = formatter.attribute_value(val) + decoded = ( + str(key) + '=' + + formatter.quoted_attribute_value(text)) + attrs.append(decoded) + close = '' + closeTag = '' + + prefix = '' + if self.prefix: + prefix = self.prefix + ":" + + if self.is_empty_element: + close = formatter.void_element_close_prefix or '' + else: + closeTag = '</%s%s>' % (prefix, self.name) + + pretty_print = self._should_pretty_print(indent_level) + space = '' + indent_space = '' + if indent_level is not None: + indent_space = (' ' * (indent_level - 1)) + if pretty_print: + space = indent_space + indent_contents = indent_level + 1 + else: + indent_contents = None + contents = self.decode_contents( + indent_contents, eventual_encoding, formatter + ) + + if self.hidden: + # This is the 'document root' object. + s = contents + else: + s = [] + attribute_string = '' + if attrs: + attribute_string = ' ' + ' '.join(attrs) + if indent_level is not None: + # Even if this particular tag is not pretty-printed, + # we should indent up to the start of the tag. + s.append(indent_space) + s.append('<%s%s%s%s>' % ( + prefix, self.name, attribute_string, close)) + if pretty_print: + s.append("\n") + s.append(contents) + if pretty_print and contents and contents[-1] != "\n": + s.append("\n") + if pretty_print and closeTag: + s.append(space) + s.append(closeTag) + if indent_level is not None and closeTag and self.next_sibling: + # Even if this particular tag is not pretty-printed, + # we're now done with the tag, and we should add a + # newline if appropriate. + s.append("\n") + s = ''.join(s) + return s + + def _should_pretty_print(self, indent_level): + """Should this tag be pretty-printed? + + Most of them should, but some (such as <pre> in HTML + documents) should not. + """ + return ( + indent_level is not None + and ( + not self.preserve_whitespace_tags + or self.name not in self.preserve_whitespace_tags + ) + ) + + def prettify(self, encoding=None, formatter="minimal"): + """Pretty-print this PageElement as a string. + + :param encoding: The eventual encoding of the string. If this is None, + a Unicode string will be returned. + :param formatter: A Formatter object, or a string naming one of + the standard formatters. + :return: A Unicode string (if encoding==None) or a bytestring + (otherwise). + """ + if encoding is None: + return self.decode(True, formatter=formatter) + else: + return self.encode(encoding, True, formatter=formatter) + + def decode_contents(self, indent_level=None, + eventual_encoding=DEFAULT_OUTPUT_ENCODING, + formatter="minimal"): + """Renders the contents of this tag as a Unicode string. + + :param indent_level: Each line of the rendering will be + indented this many spaces. Used internally in + recursive calls while pretty-printing. + + :param eventual_encoding: The tag is destined to be + encoded into this encoding. decode_contents() is _not_ + responsible for performing that encoding. This information + is passed in so that it can be substituted in if the + document contains a <META> tag that mentions the document's + encoding. + + :param formatter: A Formatter object, or a string naming one of + the standard Formatters. + """ + # First off, turn a string formatter into a Formatter object. This + # will stop the lookup from happening over and over again. + if not isinstance(formatter, Formatter): + formatter = self.formatter_for_name(formatter) + + pretty_print = (indent_level is not None) + s = [] + for c in self: + text = None + if isinstance(c, NavigableString): + text = c.output_ready(formatter) + elif isinstance(c, Tag): + s.append(c.decode(indent_level, eventual_encoding, + formatter)) + preserve_whitespace = ( + self.preserve_whitespace_tags and self.name in self.preserve_whitespace_tags + ) + if text and indent_level and not preserve_whitespace: + text = text.strip() + if text: + if pretty_print and not preserve_whitespace: + s.append(" " * (indent_level - 1)) + s.append(text) + if pretty_print and not preserve_whitespace: + s.append("\n") + return ''.join(s) + + def encode_contents( + self, indent_level=None, encoding=DEFAULT_OUTPUT_ENCODING, + formatter="minimal"): + """Renders the contents of this PageElement as a bytestring. + + :param indent_level: Each line of the rendering will be + indented this many spaces. Used internally in + recursive calls while pretty-printing. + + :param eventual_encoding: The bytestring will be in this encoding. + + :param formatter: A Formatter object, or a string naming one of + the standard Formatters. + + :return: A bytestring. + """ + contents = self.decode_contents(indent_level, encoding, formatter) + return contents.encode(encoding) + + # Old method for BS3 compatibility + def renderContents(self, encoding=DEFAULT_OUTPUT_ENCODING, + prettyPrint=False, indentLevel=0): + """Deprecated method for BS3 compatibility.""" + if not prettyPrint: + indentLevel = None + return self.encode_contents( + indent_level=indentLevel, encoding=encoding) + + #Soup methods + + def find(self, name=None, attrs={}, recursive=True, text=None, + **kwargs): + """Look in the children of this PageElement and find the first + PageElement that matches the given criteria. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param recursive: If this is True, find() will perform a + recursive search of this PageElement's children. Otherwise, + only the direct children will be considered. + :param limit: Stop looking after finding this many results. + :kwargs: A dictionary of filters on attribute values. + :return: A PageElement. + :rtype: bs4.element.Tag | bs4.element.NavigableString + """ + r = None + l = self.find_all(name, attrs, recursive, text, 1, **kwargs) + if l: + r = l[0] + return r + findChild = find #BS2 + + def find_all(self, name=None, attrs={}, recursive=True, text=None, + limit=None, **kwargs): + """Look in the children of this PageElement and find all + PageElements that match the given criteria. + + All find_* methods take a common set of arguments. See the online + documentation for detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param recursive: If this is True, find_all() will perform a + recursive search of this PageElement's children. Otherwise, + only the direct children will be considered. + :param limit: Stop looking after finding this many results. + :kwargs: A dictionary of filters on attribute values. + :return: A ResultSet of PageElements. + :rtype: bs4.element.ResultSet + """ + generator = self.descendants + if not recursive: + generator = self.children + return self._find_all(name, attrs, text, limit, generator, **kwargs) + findAll = find_all # BS3 + findChildren = find_all # BS2 + + #Generator methods + @property + def children(self): + """Iterate over all direct children of this PageElement. + + :yield: A sequence of PageElements. + """ + # return iter() to make the purpose of the method clear + return iter(self.contents) # XXX This seems to be untested. + + @property + def descendants(self): + """Iterate over all children of this PageElement in a + breadth-first sequence. + + :yield: A sequence of PageElements. + """ + if not len(self.contents): + return + stopNode = self._last_descendant().next_element + current = self.contents[0] + while current is not stopNode: + yield current + current = current.next_element + + # CSS selector code + def select_one(self, selector, namespaces=None, **kwargs): + """Perform a CSS selection operation on the current element. + + :param selector: A CSS selector. + + :param namespaces: A dictionary mapping namespace prefixes + used in the CSS selector to namespace URIs. By default, + Beautiful Soup will use the prefixes it encountered while + parsing the document. + + :param kwargs: Keyword arguments to be passed into SoupSieve's + soupsieve.select() method. + + :return: A Tag. + :rtype: bs4.element.Tag + """ + value = self.select(selector, namespaces, 1, **kwargs) + if value: + return value[0] + return None + + def select(self, selector, namespaces=None, limit=None, **kwargs): + """Perform a CSS selection operation on the current element. + + This uses the SoupSieve library. + + :param selector: A string containing a CSS selector. + + :param namespaces: A dictionary mapping namespace prefixes + used in the CSS selector to namespace URIs. By default, + Beautiful Soup will use the prefixes it encountered while + parsing the document. + + :param limit: After finding this number of results, stop looking. + + :param kwargs: Keyword arguments to be passed into SoupSieve's + soupsieve.select() method. + + :return: A ResultSet of Tags. + :rtype: bs4.element.ResultSet + """ + if namespaces is None: + namespaces = self._namespaces + + if limit is None: + limit = 0 + if soupsieve is None: + raise NotImplementedError( + "Cannot execute CSS selectors because the soupsieve package is not installed." + ) + + results = soupsieve.select(selector, self, namespaces, limit, **kwargs) + + # We do this because it's more consistent and because + # ResultSet.__getattr__ has a helpful error message. + return ResultSet(None, results) + + # Old names for backwards compatibility + def childGenerator(self): + """Deprecated generator.""" + return self.children + + def recursiveChildGenerator(self): + """Deprecated generator.""" + return self.descendants + + def has_key(self, key): + """Deprecated method. This was kind of misleading because has_key() + (attributes) was different from __in__ (contents). + + has_key() is gone in Python 3, anyway. + """ + warnings.warn('has_key is deprecated. Use has_attr("%s") instead.' % ( + key)) + return self.has_attr(key) + +# Next, a couple classes to represent queries and their results. +class SoupStrainer(object): + """Encapsulates a number of ways of matching a markup element (tag or + string). + + This is primarily used to underpin the find_* methods, but you can + create one yourself and pass it in as `parse_only` to the + `BeautifulSoup` constructor, to parse a subset of a large + document. + """ + + def __init__(self, name=None, attrs={}, text=None, **kwargs): + """Constructor. + + The SoupStrainer constructor takes the same arguments passed + into the find_* methods. See the online documentation for + detailed explanations. + + :param name: A filter on tag name. + :param attrs: A dictionary of filters on attribute values. + :param text: A filter for a NavigableString with specific text. + :kwargs: A dictionary of filters on attribute values. + """ + self.name = self._normalize_search_value(name) + if not isinstance(attrs, dict): + # Treat a non-dict value for attrs as a search for the 'class' + # attribute. + kwargs['class'] = attrs + attrs = None + + if 'class_' in kwargs: + # Treat class_="foo" as a search for the 'class' + # attribute, overriding any non-dict value for attrs. + kwargs['class'] = kwargs['class_'] + del kwargs['class_'] + + if kwargs: + if attrs: + attrs = attrs.copy() + attrs.update(kwargs) + else: + attrs = kwargs + normalized_attrs = {} + for key, value in list(attrs.items()): + normalized_attrs[key] = self._normalize_search_value(value) + + self.attrs = normalized_attrs + self.text = self._normalize_search_value(text) + + def _normalize_search_value(self, value): + # Leave it alone if it's a Unicode string, a callable, a + # regular expression, a boolean, or None. + if (isinstance(value, str) or isinstance(value, Callable) or hasattr(value, 'match') + or isinstance(value, bool) or value is None): + return value + + # If it's a bytestring, convert it to Unicode, treating it as UTF-8. + if isinstance(value, bytes): + return value.decode("utf8") + + # If it's listlike, convert it into a list of strings. + if hasattr(value, '__iter__'): + new_value = [] + for v in value: + if (hasattr(v, '__iter__') and not isinstance(v, bytes) + and not isinstance(v, str)): + # This is almost certainly the user's mistake. In the + # interests of avoiding infinite loops, we'll let + # it through as-is rather than doing a recursive call. + new_value.append(v) + else: + new_value.append(self._normalize_search_value(v)) + return new_value + + # Otherwise, convert it into a Unicode string. + # The unicode(str()) thing is so this will do the same thing on Python 2 + # and Python 3. + return str(str(value)) + + def __str__(self): + """A human-readable representation of this SoupStrainer.""" + if self.text: + return self.text + else: + return "%s|%s" % (self.name, self.attrs) + + def search_tag(self, markup_name=None, markup_attrs={}): + """Check whether a Tag with the given name and attributes would + match this SoupStrainer. + + Used prospectively to decide whether to even bother creating a Tag + object. + + :param markup_name: A tag name as found in some markup. + :param markup_attrs: A dictionary of attributes as found in some markup. + + :return: True if the prospective tag would match this SoupStrainer; + False otherwise. + """ + found = None + markup = None + if isinstance(markup_name, Tag): + markup = markup_name + markup_attrs = markup + + if isinstance(self.name, str): + # Optimization for a very common case where the user is + # searching for a tag with one specific name, and we're + # looking at a tag with a different name. + if markup and not markup.prefix and self.name != markup.name: + return False + + call_function_with_tag_data = ( + isinstance(self.name, Callable) + and not isinstance(markup_name, Tag)) + + if ((not self.name) + or call_function_with_tag_data + or (markup and self._matches(markup, self.name)) + or (not markup and self._matches(markup_name, self.name))): + if call_function_with_tag_data: + match = self.name(markup_name, markup_attrs) + else: + match = True + markup_attr_map = None + for attr, match_against in list(self.attrs.items()): + if not markup_attr_map: + if hasattr(markup_attrs, 'get'): + markup_attr_map = markup_attrs + else: + markup_attr_map = {} + for k, v in markup_attrs: + markup_attr_map[k] = v + attr_value = markup_attr_map.get(attr) + if not self._matches(attr_value, match_against): + match = False + break + if match: + if markup: + found = markup + else: + found = markup_name + if found and self.text and not self._matches(found.string, self.text): + found = None + return found + + # For BS3 compatibility. + searchTag = search_tag + + def search(self, markup): + """Find all items in `markup` that match this SoupStrainer. + + Used by the core _find_all() method, which is ultimately + called by all find_* methods. + + :param markup: A PageElement or a list of them. + """ + # 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 hasattr(markup, '__iter__') and not isinstance(markup, (Tag, str)): + 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 or self.name or self.attrs: + found = self.search_tag(markup) + # If it's text, make sure the text matches. + elif isinstance(markup, NavigableString) or \ + isinstance(markup, str): + if not self.name and not self.attrs and 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, match_against, already_tried=None): + # print(u"Matching %s against %s" % (markup, match_against)) + result = False + if isinstance(markup, list) or isinstance(markup, tuple): + # This should only happen when searching a multi-valued attribute + # like 'class'. + for item in markup: + if self._matches(item, match_against): + return True + # We didn't match any particular value of the multivalue + # attribute, but maybe we match the attribute value when + # considered as a string. + if self._matches(' '.join(markup), match_against): + return True + return False + + if match_against is True: + # True matches any non-None value. + return markup is not None + + if isinstance(match_against, Callable): + return match_against(markup) + + # Custom callables take the tag as an argument, but all + # other ways of matching match the tag name as a string. + original_markup = markup + if isinstance(markup, Tag): + markup = markup.name + + # Ensure that `markup` is either a Unicode string, or None. + markup = self._normalize_search_value(markup) + + if markup is None: + # None matches None, False, an empty string, an empty list, and so on. + return not match_against + + if (hasattr(match_against, '__iter__') + and not isinstance(match_against, str)): + # We're asked to match against an iterable of items. + # The markup must be match at least one item in the + # iterable. We'll try each one in turn. + # + # To avoid infinite recursion we need to keep track of + # items we've already seen. + if not already_tried: + already_tried = set() + for item in match_against: + if item.__hash__: + key = item + else: + key = id(item) + if key in already_tried: + continue + else: + already_tried.add(key) + if self._matches(original_markup, item, already_tried): + return True + else: + return False + + # Beyond this point we might need to run the test twice: once against + # the tag's name and once against its prefixed name. + match = False + + if not match and isinstance(match_against, str): + # Exact string match + match = markup == match_against + + if not match and hasattr(match_against, 'search'): + # Regexp match + return match_against.search(markup) + + if (not match + and isinstance(original_markup, Tag) + and original_markup.prefix): + # Try the whole thing again with the prefixed tag name. + return self._matches( + original_markup.prefix + ':' + original_markup.name, match_against + ) + + return match + + +class ResultSet(list): + """A ResultSet is just a list that keeps track of the SoupStrainer + that created it.""" + def __init__(self, source, result=()): + """Constructor. + + :param source: A SoupStrainer. + :param result: A list of PageElements. + """ + super(ResultSet, self).__init__(result) + self.source = source + + def __getattr__(self, key): + """Raise a helpful exception to explain a common code fix.""" + raise AttributeError( + "ResultSet object has no attribute '%s'. You're probably treating a list of elements like a single element. Did you call find_all() when you meant to call find()?" % key + )