NaCl settings and completed install scripts.

visual_studio/NativeClientVSAddIn/InstallerResources/third_party/etree/ElementTree.py

+#
+# ElementTree
+# $Id: ElementTree.py 3440 2008-07-18 14:45:01Z fredrik $
+#
+# light-weight XML support for Python 2.3 and later.
+#
+# history (since 1.2.6):
+# 2005-11-12 fl   added tostringlist/fromstringlist helpers
+# 2006-07-05 fl   merged in selected changes from the 1.3 sandbox
+# 2006-07-05 fl   removed support for 2.1 and earlier
+# 2007-06-21 fl   added deprecation/future warnings
+# 2007-08-25 fl   added doctype hook, added parser version attribute etc
+# 2007-08-26 fl   added new serializer code (better namespace handling, etc)
+# 2007-08-27 fl   warn for broken /tag searches on tree level
+# 2007-09-02 fl   added html/text methods to serializer (experimental)
+# 2007-09-05 fl   added method argument to tostring/tostringlist
+# 2007-09-06 fl   improved error handling
+# 2007-09-13 fl   added itertext, iterfind; assorted cleanups
+# 2007-12-15 fl   added C14N hooks, copy method (experimental)
+#
+# Copyright (c) 1999-2008 by Fredrik Lundh.  All rights reserved.
+#
+# fredrik@pythonware.com
+# http://www.pythonware.com
+#
+# --------------------------------------------------------------------
+# The ElementTree toolkit is
+#
+# Copyright (c) 1999-2008 by Fredrik Lundh
+#
+# By obtaining, using, and/or copying this software and/or its
+# associated documentation, you agree that you have read, understood,
+# and will comply with the following terms and conditions:
+#
+# Permission to use, copy, modify, and distribute this software and
+# its associated documentation for any purpose and without fee is
+# hereby granted, provided that the above copyright notice appears in
+# all copies, and that both that copyright notice and this permission
+# notice appear in supporting documentation, and that the name of
+# Secret Labs AB or the author not be used in advertising or publicity
+# pertaining to distribution of the software without specific, written
+# prior permission.
+#
+# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
+# ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
+# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+# --------------------------------------------------------------------
+
+# Licensed to PSF under a Contributor Agreement.
+# See http://www.python.org/psf/license for licensing details.
+
+__all__ = [
+    # public symbols
+    "Comment",
+    "dump",
+    "Element", "ElementTree",
+    "fromstring", "fromstringlist",
+    "iselement", "iterparse",
+    "parse", "ParseError",
+    "PI", "ProcessingInstruction",
+    "QName",
+    "SubElement",
+    "tostring", "tostringlist",
+    "TreeBuilder",
+    "VERSION",
+    "XML",
+    "XMLParser", "XMLTreeBuilder",
+    ]
+
+VERSION = "1.3.0"
+
+##
+# The <b>Element</b> type is a flexible container object, designed to
+# store hierarchical data structures in memory. The type can be
+# described as a cross between a list and a dictionary.
+# <p>
+# Each element has a number of properties associated with it:
+# <ul>
+# <li>a <i>tag</i>. This is a string identifying what kind of data
+# this element represents (the element type, in other words).</li>
+# <li>a number of <i>attributes</i>, stored in a Python dictionary.</li>
+# <li>a <i>text</i> string.</li>
+# <li>an optional <i>tail</i> string.</li>
+# <li>a number of <i>child elements</i>, stored in a Python sequence</li>
+# </ul>
+#
+# To create an element instance, use the {@link #Element} constructor
+# or the {@link #SubElement} factory function.
+# <p>
+# The {@link #ElementTree} class can be used to wrap an element
+# structure, and convert it from and to XML.
+##
+
+import sys
+import re
+import warnings
+
+
+class _SimpleElementPath(object):
+    # emulate pre-1.2 find/findtext/findall behaviour
+    def find(self, element, tag, namespaces=None):
+        for elem in element:
+            if elem.tag == tag:
+                return elem
+        return None
+    def findtext(self, element, tag, default=None, namespaces=None):
+        elem = self.find(element, tag)
+        if elem is None:
+            return default
+        return elem.text or ""
+    def iterfind(self, element, tag, namespaces=None):
+        if tag[:3] == ".//":
+            for elem in element.iter(tag[3:]):
+                yield elem
+        for elem in element:
+            if elem.tag == tag:
+                yield elem
+    def findall(self, element, tag, namespaces=None):
+        return list(self.iterfind(element, tag, namespaces))
+
+try:
+    from . import ElementPath
+except ImportError:
+    ElementPath = _SimpleElementPath()
+
+##
+# Parser error.  This is a subclass of <b>SyntaxError</b>.
+# <p>
+# In addition to the exception value, an exception instance contains a
+# specific exception code in the <b>code</b> attribute, and the line and
+# column of the error in the <b>position</b> attribute.
+
+class ParseError(SyntaxError):
+    pass
+
+# --------------------------------------------------------------------
+
+##
+# Checks if an object appears to be a valid element object.
+#
+# @param An element instance.
+# @return A true value if this is an element object.
+# @defreturn flag
+
+def iselement(element):
+    # FIXME: not sure about this; might be a better idea to look
+    # for tag/attrib/text attributes
+    return isinstance(element, Element) or hasattr(element, "tag")
+
+##
+# Element class.  This class defines the Element interface, and
+# provides a reference implementation of this interface.
+# <p>
+# The element name, attribute names, and attribute values can be
+# either ASCII strings (ordinary Python strings containing only 7-bit
+# ASCII characters) or Unicode strings.
+#
+# @param tag The element name.
+# @param attrib An optional dictionary, containing element attributes.
+# @param **extra Additional attributes, given as keyword arguments.
+# @see Element
+# @see SubElement
+# @see Comment
+# @see ProcessingInstruction
+
+class Element(object):
+    # <tag attrib>text<child/>...</tag>tail
+
+    ##
+    # (Attribute) Element tag.
+
+    tag = None
+
+    ##
+    # (Attribute) Element attribute dictionary.  Where possible, use
+    # {@link #Element.get},
+    # {@link #Element.set},
+    # {@link #Element.keys}, and
+    # {@link #Element.items} to access
+    # element attributes.
+
+    attrib = None
+
+    ##
+    # (Attribute) Text before first subelement.  This is either a
+    # string or the value None.  Note that if there was no text, this
+    # attribute may be either None or an empty string, depending on
+    # the parser.
+
+    text = None
+
+    ##
+    # (Attribute) Text after this element's end tag, but before the
+    # next sibling element's start tag.  This is either a string or
+    # the value None.  Note that if there was no text, this attribute
+    # may be either None or an empty string, depending on the parser.
+
+    tail = None # text after end tag, if any
+
+    # constructor
+
+    def __init__(self, tag, attrib={}, **extra):
+        attrib = attrib.copy()
+        attrib.update(extra)
+        self.tag = tag
+        self.attrib = attrib
+        self._children = []
+
+    def __repr__(self):
+        return "<Element %s at 0x%x>" % (repr(self.tag), id(self))
+
+    ##
+    # Creates a new element object of the same type as this element.
+    #
+    # @param tag Element tag.
+    # @param attrib Element attributes, given as a dictionary.
+    # @return A new element instance.
+
+    def makeelement(self, tag, attrib):
+        return self.__class__(tag, attrib)
+
+    ##
+    # (Experimental) Copies the current element.  This creates a
+    # shallow copy; subelements will be shared with the original tree.
+    #
+    # @return A new element instance.
+
+    def copy(self):
+        elem = self.makeelement(self.tag, self.attrib)
+        elem.text = self.text
+        elem.tail = self.tail
+        elem[:] = self
+        return elem
+
+    ##
+    # Returns the number of subelements.  Note that this only counts
+    # full elements; to check if there's any content in an element, you
+    # have to check both the length and the <b>text</b> attribute.
+    #
+    # @return The number of subelements.
+
+    def __len__(self):
+        return len(self._children)
+
+    def __nonzero__(self):
+        warnings.warn(
+            "The behavior of this method will change in future versions.  "
+            "Use specific 'len(elem)' or 'elem is not None' test instead.",
+            FutureWarning, stacklevel=2
+            )
+        return len(self._children) != 0 # emulate old behaviour, for now
+
+    ##
+    # Returns the given subelement, by index.
+    #
+    # @param index What subelement to return.
+    # @return The given subelement.
+    # @exception IndexError If the given element does not exist.
+
+    def __getitem__(self, index):
+        return self._children[index]
+
+    ##
+    # Replaces the given subelement, by index.
+    #
+    # @param index What subelement to replace.
+    # @param element The new element value.
+    # @exception IndexError If the given element does not exist.
+
+    def __setitem__(self, index, element):
+        # if isinstance(index, slice):
+        #     for elt in element:
+        #         assert iselement(elt)
+        # else:
+        #     assert iselement(element)
+        self._children[index] = element
+
+    ##
+    # Deletes the given subelement, by index.
+    #
+    # @param index What subelement to delete.
+    # @exception IndexError If the given element does not exist.
+
+    def __delitem__(self, index):
+        del self._children[index]
+
+    ##
+    # Adds a subelement to the end of this element.  In document order,
+    # the new element will appear after the last existing subelement (or
+    # directly after the text, if it's the first subelement), but before
+    # the end tag for this element.
+    #
+    # @param element The element to add.
+
+    def append(self, element):
+        # assert iselement(element)
+        self._children.append(element)
+
+    ##
+    # Appends subelements from a sequence.
+    #
+    # @param elements A sequence object with zero or more elements.
+    # @since 1.3
+
+    def extend(self, elements):
+        # for element in elements:
+        #     assert iselement(element)
+        self._children.extend(elements)
+
+    ##
+    # Inserts a subelement at the given position in this element.
+    #
+    # @param index Where to insert the new subelement.
+
+    def insert(self, index, element):
+        # assert iselement(element)
+        self._children.insert(index, element)
+
+    ##
+    # Removes a matching subelement.  Unlike the <b>find</b> methods,
+    # this method compares elements based on identity, not on tag
+    # value or contents.  To remove subelements by other means, the
+    # easiest way is often to use a list comprehension to select what
+    # elements to keep, and use slice assignment to update the parent
+    # element.
+    #
+    # @param element What element to remove.
+    # @exception ValueError If a matching element could not be found.
+
+    def remove(self, element):
+        # assert iselement(element)
+        self._children.remove(element)
+
+    ##
+    # (Deprecated) Returns all subelements.  The elements are returned
+    # in document order.
+    #
+    # @return A list of subelements.
+    # @defreturn list of Element instances
+
+    def getchildren(self):
+        warnings.warn(
+            "This method will be removed in future versions.  "
+            "Use 'list(elem)' or iteration over elem instead.",
+            DeprecationWarning, stacklevel=2
+            )
+        return self._children
+
+    ##
+    # Finds the first matching subelement, by tag name or path.
+    #
+    # @param path What element to look for.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return The first matching element, or None if no element was found.
+    # @defreturn Element or None
+
+    def find(self, path, namespaces=None):
+        return ElementPath.find(self, path, namespaces)
+
+    ##
+    # Finds text for the first matching subelement, by tag name or path.
+    #
+    # @param path What element to look for.
+    # @param default What to return if the element was not found.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return The text content of the first matching element, or the
+    #     default value no element was found.  Note that if the element
+    #     is found, but has no text content, this method returns an
+    #     empty string.
+    # @defreturn string
+
+    def findtext(self, path, default=None, namespaces=None):
+        return ElementPath.findtext(self, path, default, namespaces)
+
+    ##
+    # Finds all matching subelements, by tag name or path.
+    #
+    # @param path What element to look for.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return A list or other sequence containing all matching elements,
+    #    in document order.
+    # @defreturn list of Element instances
+
+    def findall(self, path, namespaces=None):
+        return ElementPath.findall(self, path, namespaces)
+
+    ##
+    # Finds all matching subelements, by tag name or path.
+    #
+    # @param path What element to look for.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return An iterator or sequence containing all matching elements,
+    #    in document order.
+    # @defreturn a generated sequence of Element instances
+
+    def iterfind(self, path, namespaces=None):
+        return ElementPath.iterfind(self, path, namespaces)
+
+    ##
+    # Resets an element.  This function removes all subelements, clears
+    # all attributes, and sets the <b>text</b> and <b>tail</b> attributes
+    # to None.
+
+    def clear(self):
+        self.attrib.clear()
+        self._children = []
+        self.text = self.tail = None
+
+    ##
+    # Gets an element attribute.  Equivalent to <b>attrib.get</b>, but
+    # some implementations may handle this a bit more efficiently.
+    #
+    # @param key What attribute to look for.
+    # @param default What to return if the attribute was not found.
+    # @return The attribute value, or the default value, if the
+    #     attribute was not found.
+    # @defreturn string or None
+
+    def get(self, key, default=None):
+        return self.attrib.get(key, default)
+
+    ##
+    # Sets an element attribute.  Equivalent to <b>attrib[key] = value</b>,
+    # but some implementations may handle this a bit more efficiently.
+    #
+    # @param key What attribute to set.
+    # @param value The attribute value.
+
+    def set(self, key, value):
+        self.attrib[key] = value
+
+    ##
+    # Gets a list of attribute names.  The names are returned in an
+    # arbitrary order (just like for an ordinary Python dictionary).
+    # Equivalent to <b>attrib.keys()</b>.
+    #
+    # @return A list of element attribute names.
+    # @defreturn list of strings
+
+    def keys(self):
+        return self.attrib.keys()
+
+    ##
+    # Gets element attributes, as a sequence.  The attributes are
+    # returned in an arbitrary order.  Equivalent to <b>attrib.items()</b>.
+    #
+    # @return A list of (name, value) tuples for all attributes.
+    # @defreturn list of (string, string) tuples
+
+    def items(self):
+        return self.attrib.items()
+
+    ##
+    # Creates a tree iterator.  The iterator loops over this element
+    # and all subelements, in document order, and returns all elements
+    # with a matching tag.
+    # <p>
+    # If the tree structure is modified during iteration, new or removed
+    # elements may or may not be included.  To get a stable set, use the
+    # list() function on the iterator, and loop over the resulting list.
+    #
+    # @param tag What tags to look for (default is to return all elements).
+    # @return An iterator containing all the matching elements.
+    # @defreturn iterator
+
+    def iter(self, tag=None):
+        if tag == "*":
+            tag = None
+        if tag is None or self.tag == tag:
+            yield self
+        for e in self._children:
+            for e in e.iter(tag):
+                yield e
+
+    # compatibility
+    def getiterator(self, tag=None):
+        # Change for a DeprecationWarning in 1.4
+        warnings.warn(
+            "This method will be removed in future versions.  "
+            "Use 'elem.iter()' or 'list(elem.iter())' instead.",
+            PendingDeprecationWarning, stacklevel=2
+        )
+        return list(self.iter(tag))
+
+    ##
+    # Creates a text iterator.  The iterator loops over this element
+    # and all subelements, in document order, and returns all inner
+    # text.
+    #
+    # @return An iterator containing all inner text.
+    # @defreturn iterator
+
+    def itertext(self):
+        tag = self.tag
+        if not isinstance(tag, basestring) and tag is not None:
+            return
+        if self.text:
+            yield self.text
+        for e in self:
+            for s in e.itertext():
+                yield s
+            if e.tail:
+                yield e.tail
+
+# compatibility
+_Element = _ElementInterface = Element
+
+##
+# Subelement factory.  This function creates an element instance, and
+# appends it to an existing element.
+# <p>
+# The element name, attribute names, and attribute values can be
+# either 8-bit ASCII strings or Unicode strings.
+#
+# @param parent The parent element.
+# @param tag The subelement name.
+# @param attrib An optional dictionary, containing element attributes.
+# @param **extra Additional attributes, given as keyword arguments.
+# @return An element instance.
+# @defreturn Element
+
+def SubElement(parent, tag, attrib={}, **extra):
+    attrib = attrib.copy()
+    attrib.update(extra)
+    element = parent.makeelement(tag, attrib)
+    parent.append(element)
+    return element
+
+##
+# Comment element factory.  This factory function creates a special
+# element that will be serialized as an XML comment by the standard
+# serializer.
+# <p>
+# The comment string can be either an 8-bit ASCII string or a Unicode
+# string.
+#
+# @param text A string containing the comment string.
+# @return An element instance, representing a comment.
+# @defreturn Element
+
+def Comment(text=None):
+    element = Element(Comment)
+    element.text = text
+    return element
+
+##
+# PI element factory.  This factory function creates a special element
+# that will be serialized as an XML processing instruction by the standard
+# serializer.
+#
+# @param target A string containing the PI target.
+# @param text A string containing the PI contents, if any.
+# @return An element instance, representing a PI.
+# @defreturn Element
+
+def ProcessingInstruction(target, text=None):
+    element = Element(ProcessingInstruction)
+    element.text = target
+    if text:
+        element.text = element.text + " " + text
+    return element
+
+PI = ProcessingInstruction
+
+##
+# QName wrapper.  This can be used to wrap a QName attribute value, in
+# order to get proper namespace handling on output.
+#
+# @param text A string containing the QName value, in the form {uri}local,
+#     or, if the tag argument is given, the URI part of a QName.
+# @param tag Optional tag.  If given, the first argument is interpreted as
+#     an URI, and this argument is interpreted as a local name.
+# @return An opaque object, representing the QName.
+
+class QName(object):
+    def __init__(self, text_or_uri, tag=None):
+        if tag:
+            text_or_uri = "{%s}%s" % (text_or_uri, tag)
+        self.text = text_or_uri
+    def __str__(self):
+        return self.text
+    def __hash__(self):
+        return hash(self.text)
+    def __cmp__(self, other):
+        if isinstance(other, QName):
+            return cmp(self.text, other.text)
+        return cmp(self.text, other)
+
+# --------------------------------------------------------------------
+
+##
+# ElementTree wrapper class.  This class represents an entire element
+# hierarchy, and adds some extra support for serialization to and from
+# standard XML.
+#
+# @param element Optional root element.
+# @keyparam file Optional file handle or file name.  If given, the
+#     tree is initialized with the contents of this XML file.
+
+class ElementTree(object):
+
+    def __init__(self, element=None, file=None):
+        # assert element is None or iselement(element)
+        self._root = element # first node
+        if file:
+            self.parse(file)
+
+    ##
+    # Gets the root element for this tree.
+    #
+    # @return An element instance.
+    # @defreturn Element
+
+    def getroot(self):
+        return self._root
+
+    ##
+    # Replaces the root element for this tree.  This discards the
+    # current contents of the tree, and replaces it with the given
+    # element.  Use with care.
+    #
+    # @param element An element instance.
+
+    def _setroot(self, element):
+        # assert iselement(element)
+        self._root = element
+
+    ##
+    # Loads an external XML document into this element tree.
+    #
+    # @param source A file name or file object.  If a file object is
+    #     given, it only has to implement a <b>read(n)</b> method.
+    # @keyparam parser An optional parser instance.  If not given, the
+    #     standard {@link XMLParser} parser is used.
+    # @return The document root element.
+    # @defreturn Element
+    # @exception ParseError If the parser fails to parse the document.
+
+    def parse(self, source, parser=None):
+        close_source = False
+        if not hasattr(source, "read"):
+            source = open(source, "rb")
+            close_source = True
+        try:
+            if not parser:
+                parser = XMLParser(target=TreeBuilder())
+            while 1:
+                data = source.read(65536)
+                if not data:
+                    break
+                parser.feed(data)
+            self._root = parser.close()
+            return self._root
+        finally:
+            if close_source:
+                source.close()
+
+    ##
+    # Creates a tree iterator for the root element.  The iterator loops
+    # over all elements in this tree, in document order.
+    #
+    # @param tag What tags to look for (default is to return all elements)
+    # @return An iterator.
+    # @defreturn iterator
+
+    def iter(self, tag=None):
+        # assert self._root is not None
+        return self._root.iter(tag)
+
+    # compatibility
+    def getiterator(self, tag=None):
+        # Change for a DeprecationWarning in 1.4
+        warnings.warn(
+            "This method will be removed in future versions.  "
+            "Use 'tree.iter()' or 'list(tree.iter())' instead.",
+            PendingDeprecationWarning, stacklevel=2
+        )
+        return list(self.iter(tag))
+
+    ##
+    # Finds the first toplevel element with given tag.
+    # Same as getroot().find(path).
+    #
+    # @param path What element to look for.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return The first matching element, or None if no element was found.
+    # @defreturn Element or None
+
+    def find(self, path, namespaces=None):
+        # assert self._root is not None
+        if path[:1] == "/":
+            path = "." + path
+            warnings.warn(
+                "This search is broken in 1.3 and earlier, and will be "
+                "fixed in a future version.  If you rely on the current "
+                "behaviour, change it to %r" % path,
+                FutureWarning, stacklevel=2
+                )
+        return self._root.find(path, namespaces)
+
+    ##
+    # Finds the element text for the first toplevel element with given
+    # tag.  Same as getroot().findtext(path).
+    #
+    # @param path What toplevel element to look for.
+    # @param default What to return if the element was not found.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return The text content of the first matching element, or the
+    #     default value no element was found.  Note that if the element
+    #     is found, but has no text content, this method returns an
+    #     empty string.
+    # @defreturn string
+
+    def findtext(self, path, default=None, namespaces=None):
+        # assert self._root is not None
+        if path[:1] == "/":
+            path = "." + path
+            warnings.warn(
+                "This search is broken in 1.3 and earlier, and will be "
+                "fixed in a future version.  If you rely on the current "
+                "behaviour, change it to %r" % path,
+                FutureWarning, stacklevel=2
+                )
+        return self._root.findtext(path, default, namespaces)
+
+    ##
+    # Finds all toplevel elements with the given tag.
+    # Same as getroot().findall(path).
+    #
+    # @param path What element to look for.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return A list or iterator containing all matching elements,
+    #    in document order.
+    # @defreturn list of Element instances
+
+    def findall(self, path, namespaces=None):
+        # assert self._root is not None
+        if path[:1] == "/":
+            path = "." + path
+            warnings.warn(
+                "This search is broken in 1.3 and earlier, and will be "
+                "fixed in a future version.  If you rely on the current "
+                "behaviour, change it to %r" % path,
+                FutureWarning, stacklevel=2
+                )
+        return self._root.findall(path, namespaces)
+
+    ##
+    # Finds all matching subelements, by tag name or path.
+    # Same as getroot().iterfind(path).
+    #
+    # @param path What element to look for.
+    # @keyparam namespaces Optional namespace prefix map.
+    # @return An iterator or sequence containing all matching elements,
+    #    in document order.
+    # @defreturn a generated sequence of Element instances
+
+    def iterfind(self, path, namespaces=None):
+        # assert self._root is not None
+        if path[:1] == "/":
+            path = "." + path
+            warnings.warn(
+                "This search is broken in 1.3 and earlier, and will be "
+                "fixed in a future version.  If you rely on the current "
+                "behaviour, change it to %r" % path,
+                FutureWarning, stacklevel=2
+                )
+        return self._root.iterfind(path, namespaces)
+
+    ##
+    # Writes the element tree to a file, as XML.
+    #
+    # @def write(file, **options)
+    # @param file A file name, or a file object opened for writing.
+    # @param **options Options, given as keyword arguments.
+    # @keyparam encoding Optional output encoding (default is US-ASCII).
+    # @keyparam method Optional output method ("xml", "html", "text" or
+    #     "c14n"; default is "xml").
+    # @keyparam xml_declaration Controls if an XML declaration should
+    #     be added to the file.  Use False for never, True for always,
+    #     None for only if not US-ASCII or UTF-8.  None is default.
+
+    def write(self, file_or_filename,
+              # keyword arguments
+              encoding=None,
+              xml_declaration=None,
+              default_namespace=None,
+              method=None):
+        # assert self._root is not None
+        if not method:
+            method = "xml"
+        elif method not in _serialize:
+            # FIXME: raise an ImportError for c14n if ElementC14N is missing?
+            raise ValueError("unknown method %r" % method)
+        if hasattr(file_or_filename, "write"):
+            file = file_or_filename
+        else:
+            file = open(file_or_filename, "wb")
+        write = file.write
+        if not encoding:
+            if method == "c14n":
+                encoding = "utf-8"
+            else:
+                encoding = "us-ascii"
+        elif xml_declaration or (xml_declaration is None and
+                                 encoding not in ("utf-8", "us-ascii")):
+            if method == "xml":
+                write("<?xml version='1.0' encoding='%s'?>\n" % encoding)
+        if method == "text":
+            _serialize_text(write, self._root, encoding)
+        else:
+            qnames, namespaces = _namespaces(
+                self._root, encoding, default_namespace
+                )
+            serialize = _serialize[method]
+            serialize(write, self._root, encoding, qnames, namespaces)
+        if file_or_filename is not file:
+            file.close()
+
+    def write_c14n(self, file):
+        # lxml.etree compatibility.  use output method instead
+        return self.write(file, method="c14n")
+
+# --------------------------------------------------------------------
+# serialization support
+
+def _namespaces(elem, encoding, default_namespace=None):
+    # identify namespaces used in this tree
+
+    # maps qnames to *encoded* prefix:local names
+    qnames = {None: None}
+
+    # maps uri:s to prefixes
+    namespaces = {}
+    if default_namespace:
+        namespaces[default_namespace] = ""
+
+    def encode(text):
+        return text.encode(encoding)
+
+    def add_qname(qname):
+        # calculate serialized qname representation
+        try:
+            if qname[:1] == "{":
+                uri, tag = qname[1:].rsplit("}", 1)
+                prefix = namespaces.get(uri)
+                if prefix is None:
+                    prefix = _namespace_map.get(uri)
+                    if prefix is None:
+                        prefix = "ns%d" % len(namespaces)
+                    if prefix != "xml":
+                        namespaces[uri] = prefix
+                if prefix:
+                    qnames[qname] = encode("%s:%s" % (prefix, tag))
+                else:
+                    qnames[qname] = encode(tag) # default element
+            else:
+                if default_namespace:
+                    # FIXME: can this be handled in XML 1.0?
+                    raise ValueError(
+                        "cannot use non-qualified names with "
+                        "default_namespace option"
+                        )
+                qnames[qname] = encode(qname)
+        except TypeError:
+            _raise_serialization_error(qname)
+
+    # populate qname and namespaces table
+    try:
+        iterate = elem.iter
+    except AttributeError:
+        iterate = elem.getiterator # cET compatibility
+    for elem in iterate():
+        tag = elem.tag
+        if isinstance(tag, QName):
+            if tag.text not in qnames:
+                add_qname(tag.text)
+        elif isinstance(tag, basestring):
+            if tag not in qnames:
+                add_qname(tag)
+        elif tag is not None and tag is not Comment and tag is not PI:
+            _raise_serialization_error(tag)
+        for key, value in elem.items():
+            if isinstance(key, QName):
+                key = key.text
+            if key not in qnames:
+                add_qname(key)
+            if isinstance(value, QName) and value.text not in qnames:
+                add_qname(value.text)
+        text = elem.text
+        if isinstance(text, QName) and text.text not in qnames:
+            add_qname(text.text)
+    return qnames, namespaces
+
+def _serialize_xml(write, elem, encoding, qnames, namespaces):
+    tag = elem.tag
+    text = elem.text
+    if tag is Comment:
+        write("<!--%s-->" % _encode(text, encoding))
+    elif tag is ProcessingInstruction:
+        write("<?%s?>" % _encode(text, encoding))
+    else:
+        tag = qnames[tag]
+        if tag is None:
+            if text:
+                write(_escape_cdata(text, encoding))
+            for e in elem:
+                _serialize_xml(write, e, encoding, qnames, None)
+        else:
+            write("<" + tag)
+            items = elem.items()
+            if items or namespaces:
+                if namespaces:
+                    for v, k in sorted(namespaces.items(),
+                                       key=lambda x: x[1]):  # sort on prefix
+                        if k:
+                            k = ":" + k
+                        write(" xmlns%s=\"%s\"" % (
+                            k.encode(encoding),
+                            _escape_attrib(v, encoding)
+                            ))
+                for k, v in sorted(items):  # lexical order
+                    if isinstance(k, QName):
+                        k = k.text
+                    if isinstance(v, QName):
+                        v = qnames[v.text]
+                    else:
+                        v = _escape_attrib(v, encoding)
+                    write(" %s=\"%s\"" % (qnames[k], v))
+            if text or len(elem):
+                write(">")
+                if text:
+                    write(_escape_cdata(text, encoding))
+                for e in elem:
+                    _serialize_xml(write, e, encoding, qnames, None)
+                write("</" + tag + ">")
+            else:
+                write(" />")
+    if elem.tail:
+        write(_escape_cdata(elem.tail, encoding))
+
+HTML_EMPTY = ("area", "base", "basefont", "br", "col", "frame", "hr",
+              "img", "input", "isindex", "link", "meta" "param")
+
+try:
+    HTML_EMPTY = set(HTML_EMPTY)
+except NameError:
+    pass
+
+def _serialize_html(write, elem, encoding, qnames, namespaces):
+    tag = elem.tag
+    text = elem.text
+    if tag is Comment:
+        write("<!--%s-->" % _escape_cdata(text, encoding))
+    elif tag is ProcessingInstruction:
+        write("<?%s?>" % _escape_cdata(text, encoding))
+    else:
+        tag = qnames[tag]
+        if tag is None:
+            if text:
+                write(_escape_cdata(text, encoding))
+            for e in elem:
+                _serialize_html(write, e, encoding, qnames, None)
+        else:
+            write("<" + tag)
+            items = elem.items()
+            if items or namespaces:
+                if namespaces:
+                    for v, k in sorted(namespaces.items(),
+                                       key=lambda x: x[1]):  # sort on prefix
+                        if k:
+                            k = ":" + k
+                        write(" xmlns%s=\"%s\"" % (
+                            k.encode(encoding),
+                            _escape_attrib(v, encoding)
+                            ))
+                for k, v in sorted(items):  # lexical order
+                    if isinstance(k, QName):
+                        k = k.text
+                    if isinstance(v, QName):
+                        v = qnames[v.text]
+                    else:
+                        v = _escape_attrib_html(v, encoding)
+                    # FIXME: handle boolean attributes
+                    write(" %s=\"%s\"" % (qnames[k], v))
+            write(">")
+            tag = tag.lower()
+            if text:
+                if tag == "script" or tag == "style":
+                    write(_encode(text, encoding))
+                else:
+                    write(_escape_cdata(text, encoding))
+            for e in elem:
+                _serialize_html(write, e, encoding, qnames, None)
+            if tag not in HTML_EMPTY:
+                write("</" + tag + ">")
+    if elem.tail:
+        write(_escape_cdata(elem.tail, encoding))
+
+def _serialize_text(write, elem, encoding):
+    for part in elem.itertext():
+        write(part.encode(encoding))
+    if elem.tail:
+        write(elem.tail.encode(encoding))
+
+_serialize = {
+    "xml": _serialize_xml,
+    "html": _serialize_html,
+    "text": _serialize_text,
+# this optional method is imported at the end of the module
+#   "c14n": _serialize_c14n,
+}
+
+##
+# Registers a namespace prefix.  The registry is global, and any
+# existing mapping for either the given prefix or the namespace URI
+# will be removed.
+#
+# @param prefix Namespace prefix.
+# @param uri Namespace uri.  Tags and attributes in this namespace
+#     will be serialized with the given prefix, if at all possible.
+# @exception ValueError If the prefix is reserved, or is otherwise
+#     invalid.
+
+def register_namespace(prefix, uri):
+    if re.match("ns\d+$", prefix):
+        raise ValueError("Prefix format reserved for internal use")
+    for k, v in _namespace_map.items():
+        if k == uri or v == prefix:
+            del _namespace_map[k]
+    _namespace_map[uri] = prefix
+
+_namespace_map = {
+    # "well-known" namespace prefixes
+    "http://www.w3.org/XML/1998/namespace": "xml",
+    "http://www.w3.org/1999/xhtml": "html",
+    "http://www.w3.org/1999/02/22-rdf-syntax-ns#": "rdf",
+    "http://schemas.xmlsoap.org/wsdl/": "wsdl",
+    # xml schema
+    "http://www.w3.org/2001/XMLSchema": "xs",
+    "http://www.w3.org/2001/XMLSchema-instance": "xsi",
+    # dublin core
+    "http://purl.org/dc/elements/1.1/": "dc",
+}
+
+def _raise_serialization_error(text):
+    raise TypeError(
+        "cannot serialize %r (type %s)" % (text, type(text).__name__)
+        )
+
+def _encode(text, encoding):
+    try:
+        return text.encode(encoding, "xmlcharrefreplace")
+    except (TypeError, AttributeError):
+        _raise_serialization_error(text)
+
+def _escape_cdata(text, encoding):
+    # escape character data
+    try:
+        # it's worth avoiding do-nothing calls for strings that are
+        # shorter than 500 character, or so.  assume that's, by far,
+        # the most common case in most applications.
+        if "&" in text:
+            text = text.replace("&", "&amp;")
+        if "<" in text:
+            text = text.replace("<", "&lt;")
+        if ">" in text:
+            text = text.replace(">", "&gt;")
+        return text.encode(encoding, "xmlcharrefreplace")
+    except (TypeError, AttributeError):
+        _raise_serialization_error(text)
+
+def _escape_attrib(text, encoding):
+    # escape attribute value
+    try:
+        if "&" in text:
+            text = text.replace("&", "&amp;")
+        if "<" in text:
+            text = text.replace("<", "&lt;")
+        if ">" in text:
+            text = text.replace(">", "&gt;")
+        if "\"" in text:
+            text = text.replace("\"", "&quot;")
+        if "\n" in text:
+            text = text.replace("\n", "&#10;")
+        return text.encode(encoding, "xmlcharrefreplace")
+    except (TypeError, AttributeError):
+        _raise_serialization_error(text)
+
+def _escape_attrib_html(text, encoding):
+    # escape attribute value
+    try:
+        if "&" in text:
+            text = text.replace("&", "&amp;")
+        if ">" in text:
+            text = text.replace(">", "&gt;")
+        if "\"" in text:
+            text = text.replace("\"", "&quot;")
+        return text.encode(encoding, "xmlcharrefreplace")
+    except (TypeError, AttributeError):
+        _raise_serialization_error(text)
+
+# --------------------------------------------------------------------
+
+##
+# Generates a string representation of an XML element, including all
+# subelements.
+#
+# @param element An Element instance.
+# @keyparam encoding Optional output encoding (default is US-ASCII).
+# @keyparam method Optional output method ("xml", "html", "text" or
+#     "c14n"; default is "xml").
+# @return An encoded string containing the XML data.
+# @defreturn string
+
+def tostring(element, encoding=None, method=None):
+    class dummy:
+        pass
+    data = []
+    file = dummy()
+    file.write = data.append
+    ElementTree(element).write(file, encoding, method=method)
+    return "".join(data)
+
+##
+# Generates a string representation of an XML element, including all
+# subelements.  The string is returned as a sequence of string fragments.
+#
+# @param element An Element instance.
+# @keyparam encoding Optional output encoding (default is US-ASCII).
+# @keyparam method Optional output method ("xml", "html", "text" or
+#     "c14n"; default is "xml").
+# @return A sequence object containing the XML data.
+# @defreturn sequence
+# @since 1.3
+
+def tostringlist(element, encoding=None, method=None):
+    class dummy:
+        pass
+    data = []
+    file = dummy()
+    file.write = data.append
+    ElementTree(element).write(file, encoding, method=method)
+    # FIXME: merge small fragments into larger parts
+    return data
+
+##
+# Writes an element tree or element structure to sys.stdout.  This
+# function should be used for debugging only.
+# <p>
+# The exact output format is implementation dependent.  In this
+# version, it's written as an ordinary XML file.
+#
+# @param elem An element tree or an individual element.
+
+def dump(elem):
+    # debugging
+    if not isinstance(elem, ElementTree):
+        elem = ElementTree(elem)
+    elem.write(sys.stdout)
+    tail = elem.getroot().tail
+    if not tail or tail[-1] != "\n":
+        sys.stdout.write("\n")
+
+# --------------------------------------------------------------------
+# parsing
+
+##
+# Parses an XML document into an element tree.
+#
+# @param source A filename or file object containing XML data.
+# @param parser An optional parser instance.  If not given, the
+#     standard {@link XMLParser} parser is used.
+# @return An ElementTree instance
+
+def parse(source, parser=None):
+    tree = ElementTree()
+    tree.parse(source, parser)
+    return tree
+
+##
+# Parses an XML document into an element tree incrementally, and reports
+# what's going on to the user.
+#
+# @param source A filename or file object containing XML data.
+# @param events A list of events to report back.  If omitted, only "end"
+#     events are reported.
+# @param parser An optional parser instance.  If not given, the
+#     standard {@link XMLParser} parser is used.
+# @return A (event, elem) iterator.
+
+def iterparse(source, events=None, parser=None):
+    close_source = False
+    if not hasattr(source, "read"):
+        source = open(source, "rb")
+        close_source = True
+    if not parser:
+        parser = XMLParser(target=TreeBuilder())
+    return _IterParseIterator(source, events, parser, close_source)
+
+class _IterParseIterator(object):
+
+    def __init__(self, source, events, parser, close_source=False):
+        self._file = source
+        self._close_file = close_source
+        self._events = []
+        self._index = 0
+        self._error = None
+        self.root = self._root = None
+        self._parser = parser
+        # wire up the parser for event reporting
+        parser = self._parser._parser
+        append = self._events.append
+        if events is None:
+            events = ["end"]
+        for event in events:
+            if event == "start":
+                try:
+                    parser.ordered_attributes = 1
+                    parser.specified_attributes = 1
+                    def handler(tag, attrib_in, event=event, append=append,
+                                start=self._parser._start_list):
+                        append((event, start(tag, attrib_in)))
+                    parser.StartElementHandler = handler
+                except AttributeError:
+                    def handler(tag, attrib_in, event=event, append=append,
+                                start=self._parser._start):
+                        append((event, start(tag, attrib_in)))
+                    parser.StartElementHandler = handler
+            elif event == "end":
+                def handler(tag, event=event, append=append,
+                            end=self._parser._end):
+                    append((event, end(tag)))
+                parser.EndElementHandler = handler
+            elif event == "start-ns":
+                def handler(prefix, uri, event=event, append=append):
+                    try:
+                        uri = (uri or "").encode("ascii")
+                    except UnicodeError:
+                        pass
+                    append((event, (prefix or "", uri or "")))
+                parser.StartNamespaceDeclHandler = handler
+            elif event == "end-ns":
+                def handler(prefix, event=event, append=append):
+                    append((event, None))
+                parser.EndNamespaceDeclHandler = handler
+            else:
+                raise ValueError("unknown event %r" % event)
+
+    def next(self):
+        while 1:
+            try:
+                item = self._events[self._index]
+                self._index += 1
+                return item
+            except IndexError:
+                pass
+            if self._error:
+                e = self._error
+                self._error = None
+                raise e
+            if self._parser is None:
+                self.root = self._root
+                if self._close_file:
+                    self._file.close()
+                raise StopIteration
+            # load event buffer
+            del self._events[:]
+            self._index = 0
+            data = self._file.read(16384)
+            if data:
+                try:
+                    self._parser.feed(data)
+                except SyntaxError as exc:
+                    self._error = exc
+            else:
+                self._root = self._parser.close()
+                self._parser = None
+
+    def __iter__(self):
+        return self
+
+##
+# Parses an XML document from a string constant.  This function can
+# be used to embed "XML literals" in Python code.
+#
+# @param source A string containing XML data.
+# @param parser An optional parser instance.  If not given, the
+#     standard {@link XMLParser} parser is used.
+# @return An Element instance.
+# @defreturn Element
+
+def XML(text, parser=None):
+    if not parser:
+        parser = XMLParser(target=TreeBuilder())
+    parser.feed(text)
+    return parser.close()
+
+##
+# Parses an XML document from a string constant, and also returns
+# a dictionary which maps from element id:s to elements.
+#
+# @param source A string containing XML data.
+# @param parser An optional parser instance.  If not given, the
+#     standard {@link XMLParser} parser is used.
+# @return A tuple containing an Element instance and a dictionary.
+# @defreturn (Element, dictionary)
+
+def XMLID(text, parser=None):
+    if not parser:
+        parser = XMLParser(target=TreeBuilder())
+    parser.feed(text)
+    tree = parser.close()
+    ids = {}
+    for elem in tree.iter():
+        id = elem.get("id")
+        if id:
+            ids[id] = elem
+    return tree, ids
+
+##
+# Parses an XML document from a string constant.  Same as {@link #XML}.
+#
+# @def fromstring(text)
+# @param source A string containing XML data.
+# @return An Element instance.
+# @defreturn Element
+
+fromstring = XML
+
+##
+# Parses an XML document from a sequence of string fragments.
+#
+# @param sequence A list or other sequence containing XML data fragments.
+# @param parser An optional parser instance.  If not given, the
+#     standard {@link XMLParser} parser is used.
+# @return An Element instance.
+# @defreturn Element
+# @since 1.3
+
+def fromstringlist(sequence, parser=None):
+    if not parser:
+        parser = XMLParser(target=TreeBuilder())
+    for text in sequence:
+        parser.feed(text)
+    return parser.close()
+
+# --------------------------------------------------------------------
+
+##
+# Generic element structure builder.  This builder converts a sequence
+# of {@link #TreeBuilder.start}, {@link #TreeBuilder.data}, and {@link
+# #TreeBuilder.end} method calls to a well-formed element structure.
+# <p>
+# You can use this class to build an element structure using a custom XML
+# parser, or a parser for some other XML-like format.
+#
+# @param element_factory Optional element factory.  This factory
+#    is called to create new Element instances, as necessary.
+
+class TreeBuilder(object):
+
+    def __init__(self, element_factory=None):
+        self._data = [] # data collector
+        self._elem = [] # element stack
+        self._last = None # last element
+        self._tail = None # true if we're after an end tag
+        if element_factory is None:
+            element_factory = Element
+        self._factory = element_factory
+
+    ##
+    # Flushes the builder buffers, and returns the toplevel document
+    # element.
+    #
+    # @return An Element instance.
+    # @defreturn Element
+
+    def close(self):
+        assert len(self._elem) == 0, "missing end tags"
+        assert self._last is not None, "missing toplevel element"
+        return self._last
+
+    def _flush(self):
+        if self._data:
+            if self._last is not None:
+                text = "".join(self._data)
+                if self._tail:
+                    assert self._last.tail is None, "internal error (tail)"
+                    self._last.tail = text
+                else:
+                    assert self._last.text is None, "internal error (text)"
+                    self._last.text = text
+            self._data = []
+
+    ##
+    # Adds text to the current element.
+    #
+    # @param data A string.  This should be either an 8-bit string
+    #    containing ASCII text, or a Unicode string.
+
+    def data(self, data):
+        self._data.append(data)
+
+    ##
+    # Opens a new element.
+    #
+    # @param tag The element name.
+    # @param attrib A dictionary containing element attributes.
+    # @return The opened element.
+    # @defreturn Element
+
+    def start(self, tag, attrs):
+        self._flush()
+        self._last = elem = self._factory(tag, attrs)
+        if self._elem:
+            self._elem[-1].append(elem)
+        self._elem.append(elem)
+        self._tail = 0
+        return elem
+
+    ##
+    # Closes the current element.
+    #
+    # @param tag The element name.
+    # @return The closed element.
+    # @defreturn Element
+
+    def end(self, tag):
+        self._flush()
+        self._last = self._elem.pop()
+        assert self._last.tag == tag,\
+               "end tag mismatch (expected %s, got %s)" % (
+                   self._last.tag, tag)
+        self._tail = 1
+        return self._last
+
+##
+# Element structure builder for XML source data, based on the
+# <b>expat</b> parser.
+#
+# @keyparam target Target object.  If omitted, the builder uses an
+#     instance of the standard {@link #TreeBuilder} class.
+# @keyparam html Predefine HTML entities.  This flag is not supported
+#     by the current implementation.
+# @keyparam encoding Optional encoding.  If given, the value overrides
+#     the encoding specified in the XML file.
+# @see #ElementTree
+# @see #TreeBuilder
+
+class XMLParser(object):
+
+    def __init__(self, html=0, target=None, encoding=None):
+        try:
+            from xml.parsers import expat
+        except ImportError:
+            try:
+                import pyexpat as expat
+            except ImportError:
+                raise ImportError(
+                    "No module named expat; use SimpleXMLTreeBuilder instead"
+                    )
+        parser = expat.ParserCreate(encoding, "}")
+        if target is None:
+            target = TreeBuilder()
+        # underscored names are provided for compatibility only
+        self.parser = self._parser = parser
+        self.target = self._target = target
+        self._error = expat.error
+        self._names = {} # name memo cache
+        # callbacks
+        parser.DefaultHandlerExpand = self._default
+        parser.StartElementHandler = self._start
+        parser.EndElementHandler = self._end
+        parser.CharacterDataHandler = self._data
+        # optional callbacks
+        parser.CommentHandler = self._comment
+        parser.ProcessingInstructionHandler = self._pi
+        # let expat do the buffering, if supported
+        try:
+            self._parser.buffer_text = 1
+        except AttributeError:
+            pass
+        # use new-style attribute handling, if supported
+        try:
+            self._parser.ordered_attributes = 1
+            self._parser.specified_attributes = 1
+            parser.StartElementHandler = self._start_list
+        except AttributeError:
+            pass
+        self._doctype = None
+        self.entity = {}
+        try:
+            self.version = "Expat %d.%d.%d" % expat.version_info
+        except AttributeError:
+            pass # unknown
+
+    def _raiseerror(self, value):
+        err = ParseError(value)
+        err.code = value.code
+        err.position = value.lineno, value.offset
+        raise err
+
+    def _fixtext(self, text):
+        # convert text string to ascii, if possible
+        try:
+            return text.encode("ascii")
+        except UnicodeError:
+            return text
+
+    def _fixname(self, key):
+        # expand qname, and convert name string to ascii, if possible
+        try:
+            name = self._names[key]
+        except KeyError:
+            name = key
+            if "}" in name:
+                name = "{" + name
+            self._names[key] = name = self._fixtext(name)
+        return name
+
+    def _start(self, tag, attrib_in):
+        fixname = self._fixname
+        fixtext = self._fixtext
+        tag = fixname(tag)
+        attrib = {}
+        for key, value in attrib_in.items():
+            attrib[fixname(key)] = fixtext(value)
+        return self.target.start(tag, attrib)
+
+    def _start_list(self, tag, attrib_in):
+        fixname = self._fixname
+        fixtext = self._fixtext
+        tag = fixname(tag)
+        attrib = {}
+        if attrib_in:
+            for i in range(0, len(attrib_in), 2):
+                attrib[fixname(attrib_in[i])] = fixtext(attrib_in[i+1])
+        return self.target.start(tag, attrib)
+
+    def _data(self, text):
+        return self.target.data(self._fixtext(text))
+
+    def _end(self, tag):
+        return self.target.end(self._fixname(tag))
+
+    def _comment(self, data):
+        try:
+            comment = self.target.comment
+        except AttributeError:
+            pass
+        else:
+            return comment(self._fixtext(data))
+
+    def _pi(self, target, data):
+        try:
+            pi = self.target.pi
+        except AttributeError:
+            pass
+        else:
+            return pi(self._fixtext(target), self._fixtext(data))
+
+    def _default(self, text):
+        prefix = text[:1]
+        if prefix == "&":
+            # deal with undefined entities
+            try:
+                self.target.data(self.entity[text[1:-1]])
+            except KeyError:
+                from xml.parsers import expat
+                err = expat.error(
+                    "undefined entity %s: line %d, column %d" %
+                    (text, self._parser.ErrorLineNumber,
+                    self._parser.ErrorColumnNumber)
+                    )
+                err.code = 11 # XML_ERROR_UNDEFINED_ENTITY
+                err.lineno = self._parser.ErrorLineNumber
+                err.offset = self._parser.ErrorColumnNumber
+                raise err
+        elif prefix == "<" and text[:9] == "<!DOCTYPE":
+            self._doctype = [] # inside a doctype declaration
+        elif self._doctype is not None:
+            # parse doctype contents
+            if prefix == ">":
+                self._doctype = None
+                return
+            text = text.strip()
+            if not text:
+                return
+            self._doctype.append(text)
+            n = len(self._doctype)
+            if n > 2:
+                type = self._doctype[1]
+                if type == "PUBLIC" and n == 4:
+                    name, type, pubid, system = self._doctype
+                elif type == "SYSTEM" and n == 3:
+                    name, type, system = self._doctype
+                    pubid = None
+                else:
+                    return
+                if pubid:
+                    pubid = pubid[1:-1]
+                if hasattr(self.target, "doctype"):
+                    self.target.doctype(name, pubid, system[1:-1])
+                elif self.doctype is not self._XMLParser__doctype:
+                    # warn about deprecated call
+                    self._XMLParser__doctype(name, pubid, system[1:-1])
+                    self.doctype(name, pubid, system[1:-1])
+                self._doctype = None
+
+    ##
+    # (Deprecated) Handles a doctype declaration.
+    #
+    # @param name Doctype name.
+    # @param pubid Public identifier.
+    # @param system System identifier.
+
+    def doctype(self, name, pubid, system):
+        """This method of XMLParser is deprecated."""
+        warnings.warn(
+            "This method of XMLParser is deprecated.  Define doctype() "
+            "method on the TreeBuilder target.",
+            DeprecationWarning,
+            )
+
+    # sentinel, if doctype is redefined in a subclass
+    __doctype = doctype
+
+    ##
+    # Feeds data to the parser.
+    #
+    # @param data Encoded data.
+
+    def feed(self, data):
+        try:
+            self._parser.Parse(data, 0)
+        except self._error, v:
+            self._raiseerror(v)
+
+    ##
+    # Finishes feeding data to the parser.
+    #
+    # @return An element structure.
+    # @defreturn Element
+
+    def close(self):
+        try:
+            self._parser.Parse("", 1) # end of data
+        except self._error, v:
+            self._raiseerror(v)
+        tree = self.target.close()
+        del self.target, self._parser # get rid of circular references
+        return tree
+
+# compatibility
+XMLTreeBuilder = XMLParser
+
+# workaround circular import.
+try:
+    from ElementC14N import _serialize_c14n
+    _serialize["c14n"] = _serialize_c14n
+except ImportError:
+    pass