# functions for tree cleanup and removing elements from subtrees def cleanup_namespaces(tree_or_element, top_nsmap=None, keep_ns_prefixes=None): u"""cleanup_namespaces(tree_or_element, top_nsmap=None, keep_ns_prefixes=None) Remove all namespace declarations from a subtree that are not used by any of the elements or attributes in that tree. If a 'top_nsmap' is provided, it must be a mapping from prefixes to namespace URIs. These namespaces will be declared on the top element of the subtree before running the cleanup, which allows moving namespace declarations to the top of the tree. If a 'keep_ns_prefixes' is provided, it must be a list of prefixes. These prefixes will not be removed as part of the cleanup. """ element = _rootNodeOrRaise(tree_or_element) c_element = element._c_node if top_nsmap: doc = element._doc # declare namespaces from nsmap, then apply them to the subtree _setNodeNamespaces(c_element, doc, None, top_nsmap) moveNodeToDocument(doc, c_element.doc, c_element) keep_ns_prefixes = ( set([_utf8(prefix) for prefix in keep_ns_prefixes]) if keep_ns_prefixes else None) _removeUnusedNamespaceDeclarations(c_element, keep_ns_prefixes) def strip_attributes(tree_or_element, *attribute_names): u"""strip_attributes(tree_or_element, *attribute_names) Delete all attributes with the provided attribute names from an Element (or ElementTree) and its descendants. Attribute names can contain wildcards as in `_Element.iter`. Example usage:: strip_attributes(root_element, 'simpleattr', '{http://some/ns}attrname', '{http://other/ns}*') """ cdef _MultiTagMatcher matcher element = _rootNodeOrRaise(tree_or_element) if not attribute_names: return matcher = _MultiTagMatcher.__new__(_MultiTagMatcher, attribute_names) matcher.cacheTags(element._doc) if matcher.rejectsAllAttributes(): return _strip_attributes(element._c_node, matcher) cdef _strip_attributes(xmlNode* c_node, _MultiTagMatcher matcher): cdef xmlAttr* c_attr cdef xmlAttr* c_next_attr tree.BEGIN_FOR_EACH_ELEMENT_FROM(c_node, c_node, 1) if c_node.type == tree.XML_ELEMENT_NODE: c_attr = c_node.properties while c_attr is not NULL: c_next_attr = c_attr.next if matcher.matchesAttribute(c_attr): tree.xmlRemoveProp(c_attr) c_attr = c_next_attr tree.END_FOR_EACH_ELEMENT_FROM(c_node) def strip_elements(tree_or_element, *tag_names, bint with_tail=True): u"""strip_elements(tree_or_element, *tag_names, with_tail=True) Delete all elements with the provided tag names from a tree or subtree. This will remove the elements and their entire subtree, including all their attributes, text content and descendants. It will also remove the tail text of the element unless you explicitly set the ``with_tail`` keyword argument option to False. Tag names can contain wildcards as in `_Element.iter`. Note that this will not delete the element (or ElementTree root element) that you passed even if it matches. It will only treat its descendants. If you want to include the root element, check its tag name directly before even calling this function. Example usage:: strip_elements(some_element, 'simpletagname', # non-namespaced tag '{http://some/ns}tagname', # namespaced tag '{http://some/other/ns}*' # any tag from a namespace lxml.etree.Comment # comments ) """ cdef _MultiTagMatcher matcher doc = _documentOrRaise(tree_or_element) element = _rootNodeOrRaise(tree_or_element) if not tag_names: return matcher = _MultiTagMatcher.__new__(_MultiTagMatcher, tag_names) matcher.cacheTags(doc) if matcher.rejectsAll(): return if isinstance(tree_or_element, _ElementTree): # include PIs and comments next to the root node if matcher.matchesType(tree.XML_COMMENT_NODE): _removeSiblings(element._c_node, tree.XML_COMMENT_NODE, with_tail) if matcher.matchesType(tree.XML_PI_NODE): _removeSiblings(element._c_node, tree.XML_PI_NODE, with_tail) _strip_elements(doc, element._c_node, matcher, with_tail) cdef _strip_elements(_Document doc, xmlNode* c_node, _MultiTagMatcher matcher, bint with_tail): cdef xmlNode* c_child cdef xmlNode* c_next tree.BEGIN_FOR_EACH_ELEMENT_FROM(c_node, c_node, 1) if c_node.type == tree.XML_ELEMENT_NODE: # we run through the children here to prevent any problems # with the tree iteration which would occur if we unlinked the # c_node itself c_child = _findChildForwards(c_node, 0) while c_child is not NULL: c_next = _nextElement(c_child) if matcher.matches(c_child): if c_child.type == tree.XML_ELEMENT_NODE: if not with_tail: tree.xmlUnlinkNode(c_child) _removeNode(doc, c_child) else: if with_tail: _removeText(c_child.next) tree.xmlUnlinkNode(c_child) attemptDeallocation(c_child) c_child = c_next tree.END_FOR_EACH_ELEMENT_FROM(c_node) def strip_tags(tree_or_element, *tag_names): u"""strip_tags(tree_or_element, *tag_names) Delete all elements with the provided tag names from a tree or subtree. This will remove the elements and their attributes, but *not* their text/tail content or descendants. Instead, it will merge the text content and children of the element into its parent. Tag names can contain wildcards as in `_Element.iter`. Note that this will not delete the element (or ElementTree root element) that you passed even if it matches. It will only treat its descendants. Example usage:: strip_tags(some_element, 'simpletagname', # non-namespaced tag '{http://some/ns}tagname', # namespaced tag '{http://some/other/ns}*' # any tag from a namespace Comment # comments (including their text!) ) """ cdef _MultiTagMatcher matcher doc = _documentOrRaise(tree_or_element) element = _rootNodeOrRaise(tree_or_element) if not tag_names: return matcher = _MultiTagMatcher.__new__(_MultiTagMatcher, tag_names) matcher.cacheTags(doc) if matcher.rejectsAll(): return if isinstance(tree_or_element, _ElementTree): # include PIs and comments next to the root node if matcher.matchesType(tree.XML_COMMENT_NODE): _removeSiblings(element._c_node, tree.XML_COMMENT_NODE, 0) if matcher.matchesType(tree.XML_PI_NODE): _removeSiblings(element._c_node, tree.XML_PI_NODE, 0) _strip_tags(doc, element._c_node, matcher) cdef _strip_tags(_Document doc, xmlNode* c_node, _MultiTagMatcher matcher): cdef xmlNode* c_child cdef xmlNode* c_next tree.BEGIN_FOR_EACH_ELEMENT_FROM(c_node, c_node, 1) if c_node.type == tree.XML_ELEMENT_NODE: # we run through the children here to prevent any problems # with the tree iteration which would occur if we unlinked the # c_node itself c_child = _findChildForwards(c_node, 0) while c_child is not NULL: if not matcher.matches(c_child): c_child = _nextElement(c_child) continue if c_child.type == tree.XML_ELEMENT_NODE: c_next = _findChildForwards(c_child, 0) or _nextElement(c_child) _replaceNodeByChildren(doc, c_child) if not attemptDeallocation(c_child): if c_child.nsDef is not NULL: # make namespaces absolute moveNodeToDocument(doc, doc._c_doc, c_child) c_child = c_next else: c_next = _nextElement(c_child) tree.xmlUnlinkNode(c_child) attemptDeallocation(c_child) c_child = c_next tree.END_FOR_EACH_ELEMENT_FROM(c_node)