~bzr-pqm/bzr/bzr.dev

72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
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#
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# ElementTree
314 by Martin Pool
- Update ElementTree to 1.2.6
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# $Id: ElementTree.py 2326 2005-03-17 07:45:21Z fredrik $
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
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#
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# light-weight XML support for Python 1.5.2 and later.
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#
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# history:
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# 2001-10-20 fl   created (from various sources)
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# 2001-11-01 fl   return root from parse method
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# 2002-02-16 fl   sort attributes in lexical order
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# 2002-04-06 fl   TreeBuilder refactoring, added PythonDoc markup
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# 2002-05-01 fl   finished TreeBuilder refactoring
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# 2002-07-14 fl   added basic namespace support to ElementTree.write
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# 2002-07-25 fl   added QName attribute support
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# 2002-10-20 fl   fixed encoding in write
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# 2002-11-24 fl   changed default encoding to ascii; fixed attribute encoding
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# 2002-11-27 fl   accept file objects or file names for parse/write
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# 2002-12-04 fl   moved XMLTreeBuilder back to this module
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# 2003-01-11 fl   fixed entity encoding glitch for us-ascii
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# 2003-02-13 fl   added XML literal factory
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# 2003-02-21 fl   added ProcessingInstruction/PI factory
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# 2003-05-11 fl   added tostring/fromstring helpers
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# 2003-05-26 fl   added ElementPath support
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# 2003-07-05 fl   added makeelement factory method
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# 2003-07-28 fl   added more well-known namespace prefixes
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# 2003-08-15 fl   fixed typo in ElementTree.findtext (Thomas Dartsch)
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# 2003-09-04 fl   fall back on emulator if ElementPath is not installed
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# 2003-10-31 fl   markup updates
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# 2003-11-15 fl   fixed nested namespace bug
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# 2004-03-28 fl   added XMLID helper
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# 2004-06-02 fl   added default support to findtext
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# 2004-06-08 fl   fixed encoding of non-ascii element/attribute names
314 by Martin Pool
- Update ElementTree to 1.2.6
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# 2004-08-23 fl   take advantage of post-2.1 expat features
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# 2005-02-01 fl   added iterparse implementation
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# 2005-03-02 fl   fixed iterparse support for pre-2.2 versions
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
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#
314 by Martin Pool
- Update ElementTree to 1.2.6
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# Copyright (c) 1999-2005 by Fredrik Lundh.  All rights reserved.
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
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#
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# fredrik@pythonware.com
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# http://www.pythonware.com
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#
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# --------------------------------------------------------------------
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# The ElementTree toolkit is
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#
314 by Martin Pool
- Update ElementTree to 1.2.6
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# Copyright (c) 1999-2005 by Fredrik Lundh
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
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#
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# By obtaining, using, and/or copying this software and/or its
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# associated documentation, you agree that you have read, understood,
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# and will comply with the following terms and conditions:
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#
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# Permission to use, copy, modify, and distribute this software and
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# its associated documentation for any purpose and without fee is
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# hereby granted, provided that the above copyright notice appears in
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# all copies, and that both that copyright notice and this permission
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# notice appear in supporting documentation, and that the name of
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# Secret Labs AB or the author not be used in advertising or publicity
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# pertaining to distribution of the software without specific, written
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# prior permission.
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#
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# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
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# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
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# ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
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# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
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# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
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# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
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# OF THIS SOFTWARE.
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# --------------------------------------------------------------------
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__all__ = [
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    # public symbols
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    "Comment",
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    "dump",
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    "Element", "ElementTree",
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    "fromstring",
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    "iselement", "iterparse",
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    "parse",
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    "PI", "ProcessingInstruction",
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    "QName",
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    "SubElement",
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    "tostring",
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    "TreeBuilder",
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    "VERSION", "XML",
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    "XMLTreeBuilder",
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    ]
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##
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# The <b>Element</b> type is a flexible container object, designed to
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# store hierarchical data structures in memory. The type can be
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# described as a cross between a list and a dictionary.
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# <p>
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# Each element has a number of properties associated with it:
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# <ul>
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# <li>a <i>tag</i>. This is a string identifying what kind of data
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# this element represents (the element type, in other words).</li>
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# <li>a number of <i>attributes</i>, stored in a Python dictionary.</li>
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# <li>a <i>text</i> string.</li>
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# <li>an optional <i>tail</i> string.</li>
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# <li>a number of <i>child elements</i>, stored in a Python sequence</li>
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# </ul>
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#
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# To create an element instance, use the {@link #Element} or {@link
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# #SubElement} factory functions.
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# <p>
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# The {@link #ElementTree} class can be used to wrap an element
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# structure, and convert it from and to XML.
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##
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import string, sys, re
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class _SimpleElementPath:
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    # emulate pre-1.2 find/findtext/findall behaviour
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    def find(self, element, tag):
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        for elem in element:
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            if elem.tag == tag:
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                return elem
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        return None
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    def findtext(self, element, tag, default=None):
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        for elem in element:
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            if elem.tag == tag:
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                return elem.text or ""
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        return default
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    def findall(self, element, tag):
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        if tag[:3] == ".//":
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            return element.getiterator(tag[3:])
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        result = []
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        for elem in element:
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            if elem.tag == tag:
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                result.append(elem)
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        return result
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try:
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    import ElementPath
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except ImportError:
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    # FIXME: issue warning in this case?
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    ElementPath = _SimpleElementPath()
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# TODO: add support for custom namespace resolvers/default namespaces
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# TODO: add improved support for incremental parsing
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VERSION = "1.2.6"
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##
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# Internal element class.  This class defines the Element interface,
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# and provides a reference implementation of this interface.
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# <p>
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# You should not create instances of this class directly.  Use the
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# appropriate factory functions instead, such as {@link #Element}
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# and {@link #SubElement}.
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#
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# @see Element
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# @see SubElement
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# @see Comment
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# @see ProcessingInstruction
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class _ElementInterface:
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    # <tag attrib>text<child/>...</tag>tail
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    ##
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    # (Attribute) Element tag.
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    tag = None
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    ##
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    # (Attribute) Element attribute dictionary.  Where possible, use
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    # {@link #_ElementInterface.get},
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    # {@link #_ElementInterface.set},
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    # {@link #_ElementInterface.keys}, and
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    # {@link #_ElementInterface.items} to access
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    # element attributes.
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    attrib = None
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    ##
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    # (Attribute) Text before first subelement.  This is either a
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    # string or the value None, if there was no text.
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    text = None
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    ##
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    # (Attribute) Text after this element's end tag, but before the
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    # next sibling element's start tag.  This is either a string or
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    # the value None, if there was no text.
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    tail = None # text after end tag, if any
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    def __init__(self, tag, attrib):
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        self.tag = tag
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        self.attrib = attrib
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        self._children = []
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    def __repr__(self):
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        return "<Element %s at %x>" % (self.tag, id(self))
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    ##
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    # Creates a new element object of the same type as this element.
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    #
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    # @param tag Element tag.
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    # @param attrib Element attributes, given as a dictionary.
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    # @return A new element instance.
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    def makeelement(self, tag, attrib):
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        return Element(tag, attrib)
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    ##
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    # Returns the number of subelements.
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    #
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    # @return The number of subelements.
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    def __len__(self):
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        return len(self._children)
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    ##
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    # Returns the given subelement.
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    #
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    # @param index What subelement to return.
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    # @return The given subelement.
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    # @exception IndexError If the given element does not exist.
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    def __getitem__(self, index):
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        return self._children[index]
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    ##
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    # Replaces the given subelement.
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    #
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    # @param index What subelement to replace.
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    # @param element The new element value.
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    # @exception IndexError If the given element does not exist.
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    # @exception AssertionError If element is not a valid object.
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    def __setitem__(self, index, element):
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        assert iselement(element)
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        self._children[index] = element
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    ##
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    # Deletes the given subelement.
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    #
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    # @param index What subelement to delete.
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    # @exception IndexError If the given element does not exist.
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    def __delitem__(self, index):
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        del self._children[index]
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    ##
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    # Returns a list containing subelements in the given range.
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    #
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    # @param start The first subelement to return.
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    # @param stop The first subelement that shouldn't be returned.
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    # @return A sequence object containing subelements.
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    def __getslice__(self, start, stop):
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        return self._children[start:stop]
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    ##
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    # Replaces a number of subelements with elements from a sequence.
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    #
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    # @param start The first subelement to replace.
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    # @param stop The first subelement that shouldn't be replaced.
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    # @param elements A sequence object with zero or more elements.
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    # @exception AssertionError If a sequence member is not a valid object.
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    def __setslice__(self, start, stop, elements):
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        for element in elements:
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            assert iselement(element)
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        self._children[start:stop] = list(elements)
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    ##
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    # Deletes a number of subelements.
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    #
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    # @param start The first subelement to delete.
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    # @param stop The first subelement to leave in there.
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    def __delslice__(self, start, stop):
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        del self._children[start:stop]
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    ##
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    # Adds a subelement to the end of this element.
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    #
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    # @param element The element to add.
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    # @exception AssertionError If a sequence member is not a valid object.
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    def append(self, element):
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        assert iselement(element)
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        self._children.append(element)
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    ##
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    # Inserts a subelement at the given position in this element.
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    #
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    # @param index Where to insert the new subelement.
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    # @exception AssertionError If the element is not a valid object.
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    def insert(self, index, element):
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        assert iselement(element)
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        self._children.insert(index, element)
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    ##
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    # Removes a matching subelement.  Unlike the <b>find</b> methods,
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    # this method compares elements based on identity, not on tag
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    # value or contents.
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    #
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    # @param element What element to remove.
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    # @exception ValueError If a matching element could not be found.
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    # @exception AssertionError If the element is not a valid object.
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    def remove(self, element):
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        assert iselement(element)
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        self._children.remove(element)
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    ##
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    # Returns all subelements.  The elements are returned in document
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    # order.
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    #
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    # @return A list of subelements.
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    # @defreturn list of Element instances
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    def getchildren(self):
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        return self._children
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    ##
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    # Finds the first matching subelement, by tag name or path.
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    #
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    # @param path What element to look for.
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    # @return The first matching element, or None if no element was found.
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    # @defreturn Element or None
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    def find(self, path):
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        return ElementPath.find(self, path)
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    ##
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    # Finds text for the first matching subelement, by tag name or path.
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    #
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    # @param path What element to look for.
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    # @param default What to return if the element was not found.
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    # @return The text content of the first matching element, or the
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    #     default value no element was found.  Note that if the element
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    #     has is found, but has no text content, this method returns an
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    #     empty string.
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    # @defreturn string
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    def findtext(self, path, default=None):
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        return ElementPath.findtext(self, path, default)
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    ##
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    # Finds all matching subelements, by tag name or path.
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    #
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    # @param path What element to look for.
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    # @return A list or iterator containing all matching elements,
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    #    in document order.
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    # @defreturn list of Element instances
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    def findall(self, path):
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        return ElementPath.findall(self, path)
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    ##
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    # Resets an element.  This function removes all subelements, clears
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    # all attributes, and sets the text and tail attributes to None.
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    def clear(self):
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        self.attrib.clear()
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        self._children = []
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        self.text = self.tail = None
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    ##
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    # Gets an element attribute.
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    #
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    # @param key What attribute to look for.
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    # @param default What to return if the attribute was not found.
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    # @return The attribute value, or the default value, if the
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    #     attribute was not found.
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    # @defreturn string or None
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    def get(self, key, default=None):
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        return self.attrib.get(key, default)
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375
    ##
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    # Sets an element attribute.
377
    #
378
    # @param key What attribute to set.
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    # @param value The attribute value.
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    def set(self, key, value):
382
        self.attrib[key] = value
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384
    ##
385
    # Gets a list of attribute names.  The names are returned in an
386
    # arbitrary order (just like for an ordinary Python dictionary).
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    #
388
    # @return A list of element attribute names.
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    # @defreturn list of strings
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    def keys(self):
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        return self.attrib.keys()
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    ##
395
    # Gets element attributes, as a sequence.  The attributes are
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    # returned in an arbitrary order.
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    #
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    # @return A list of (name, value) tuples for all attributes.
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    # @defreturn list of (string, string) tuples
400
401
    def items(self):
402
        return self.attrib.items()
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404
    ##
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    # Creates a tree iterator.  The iterator loops over this element
406
    # and all subelements, in document order, and returns all elements
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    # with a matching tag.
408
    # <p>
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    # If the tree structure is modified during iteration, the result
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    # is undefined.
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    #
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    # @param tag What tags to look for (default is to return all elements).
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    # @return A list or iterator containing all the matching elements.
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    # @defreturn list or iterator
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    def getiterator(self, tag=None):
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        nodes = []
418
        if tag == "*":
419
            tag = None
420
        if tag is None or self.tag == tag:
421
            nodes.append(self)
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        for node in self._children:
423
            nodes.extend(node.getiterator(tag))
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        return nodes
425
426
# compatibility
427
_Element = _ElementInterface
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##
430
# Element factory.  This function returns an object implementing the
431
# standard Element interface.  The exact class or type of that object
432
# is implementation dependent, but it will always be compatible with
433
# the {@link #_ElementInterface} class in this module.
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# <p>
435
# The element name, attribute names, and attribute values can be
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# either 8-bit ASCII strings or Unicode strings.
437
#
438
# @param tag The element name.
439
# @param attrib An optional dictionary, containing element attributes.
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# @param **extra Additional attributes, given as keyword arguments.
441
# @return An element instance.
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# @defreturn Element
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def Element(tag, attrib={}, **extra):
445
    attrib = attrib.copy()
446
    attrib.update(extra)
447
    return _ElementInterface(tag, attrib)
448
449
##
450
# Subelement factory.  This function creates an element instance, and
451
# appends it to an existing element.
452
# <p>
453
# The element name, attribute names, and attribute values can be
454
# either 8-bit ASCII strings or Unicode strings.
455
#
456
# @param parent The parent element.
457
# @param tag The subelement name.
458
# @param attrib An optional dictionary, containing element attributes.
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# @param **extra Additional attributes, given as keyword arguments.
460
# @return An element instance.
461
# @defreturn Element
462
463
def SubElement(parent, tag, attrib={}, **extra):
464
    attrib = attrib.copy()
465
    attrib.update(extra)
466
    element = parent.makeelement(tag, attrib)
467
    parent.append(element)
468
    return element
469
470
##
471
# Comment element factory.  This factory function creates a special
472
# element that will be serialized as an XML comment.
473
# <p>
474
# The comment string can be either an 8-bit ASCII string or a Unicode
475
# string.
476
#
477
# @param text A string containing the comment string.
478
# @return An element instance, representing a comment.
479
# @defreturn Element
480
481
def Comment(text=None):
482
    element = Element(Comment)
483
    element.text = text
484
    return element
485
486
##
487
# PI element factory.  This factory function creates a special element
488
# that will be serialized as an XML processing instruction.
489
#
490
# @param target A string containing the PI target.
491
# @param text A string containing the PI contents, if any.
492
# @return An element instance, representing a PI.
493
# @defreturn Element
494
495
def ProcessingInstruction(target, text=None):
496
    element = Element(ProcessingInstruction)
497
    element.text = target
498
    if text:
499
        element.text = element.text + " " + text
500
    return element
501
502
PI = ProcessingInstruction
503
504
##
505
# QName wrapper.  This can be used to wrap a QName attribute value, in
506
# order to get proper namespace handling on output.
507
#
508
# @param text A string containing the QName value, in the form {uri}local,
509
#     or, if the tag argument is given, the URI part of a QName.
510
# @param tag Optional tag.  If given, the first argument is interpreted as
511
#     an URI, and this argument is interpreted as a local name.
512
# @return An opaque object, representing the QName.
513
514
class QName:
515
    def __init__(self, text_or_uri, tag=None):
516
        if tag:
517
            text_or_uri = "{%s}%s" % (text_or_uri, tag)
518
        self.text = text_or_uri
519
    def __str__(self):
520
        return self.text
521
    def __hash__(self):
522
        return hash(self.text)
523
    def __cmp__(self, other):
524
        if isinstance(other, QName):
525
            return cmp(self.text, other.text)
526
        return cmp(self.text, other)
527
528
##
529
# ElementTree wrapper class.  This class represents an entire element
530
# hierarchy, and adds some extra support for serialization to and from
531
# standard XML.
532
#
533
# @param element Optional root element.
534
# @keyparam file Optional file handle or name.  If given, the
535
#     tree is initialized with the contents of this XML file.
536
537
class ElementTree:
538
539
    def __init__(self, element=None, file=None):
540
        assert element is None or iselement(element)
541
        self._root = element # first node
542
        if file:
543
            self.parse(file)
544
545
    ##
546
    # Gets the root element for this tree.
547
    #
548
    # @return An element instance.
549
    # @defreturn Element
550
551
    def getroot(self):
552
        return self._root
553
554
    ##
555
    # Replaces the root element for this tree.  This discards the
556
    # current contents of the tree, and replaces it with the given
557
    # element.  Use with care.
558
    #
559
    # @param element An element instance.
560
561
    def _setroot(self, element):
562
        assert iselement(element)
563
        self._root = element
564
565
    ##
566
    # Loads an external XML document into this element tree.
567
    #
568
    # @param source A file name or file object.
569
    # @param parser An optional parser instance.  If not given, the
570
    #     standard {@link XMLTreeBuilder} parser is used.
571
    # @return The document root element.
572
    # @defreturn Element
573
574
    def parse(self, source, parser=None):
575
        if not hasattr(source, "read"):
576
            source = open(source, "rb")
577
        if not parser:
578
            parser = XMLTreeBuilder()
579
        while 1:
580
            data = source.read(32768)
581
            if not data:
582
                break
583
            parser.feed(data)
584
        self._root = parser.close()
585
        return self._root
586
587
    ##
588
    # Creates a tree iterator for the root element.  The iterator loops
589
    # over all elements in this tree, in document order.
590
    #
591
    # @param tag What tags to look for (default is to return all elements)
592
    # @return An iterator.
593
    # @defreturn iterator
594
595
    def getiterator(self, tag=None):
596
        assert self._root is not None
597
        return self._root.getiterator(tag)
598
599
    ##
600
    # Finds the first toplevel element with given tag.
601
    # Same as getroot().find(path).
602
    #
603
    # @param path What element to look for.
604
    # @return The first matching element, or None if no element was found.
605
    # @defreturn Element or None
606
607
    def find(self, path):
608
        assert self._root is not None
609
        if path[:1] == "/":
610
            path = "." + path
611
        return self._root.find(path)
612
613
    ##
614
    # Finds the element text for the first toplevel element with given
615
    # tag.  Same as getroot().findtext(path).
616
    #
617
    # @param path What toplevel element to look for.
618
    # @param default What to return if the element was not found.
619
    # @return The text content of the first matching element, or the
620
    #     default value no element was found.  Note that if the element
621
    #     has is found, but has no text content, this method returns an
622
    #     empty string.
623
    # @defreturn string
624
625
    def findtext(self, path, default=None):
626
        assert self._root is not None
627
        if path[:1] == "/":
628
            path = "." + path
629
        return self._root.findtext(path, default)
630
631
    ##
632
    # Finds all toplevel elements with the given tag.
633
    # Same as getroot().findall(path).
634
    #
635
    # @param path What element to look for.
636
    # @return A list or iterator containing all matching elements,
637
    #    in document order.
638
    # @defreturn list of Element instances
639
640
    def findall(self, path):
641
        assert self._root is not None
642
        if path[:1] == "/":
643
            path = "." + path
644
        return self._root.findall(path)
645
646
    ##
647
    # Writes the element tree to a file, as XML.
648
    #
649
    # @param file A file name, or a file object opened for writing.
650
    # @param encoding Optional output encoding (default is US-ASCII).
651
652
    def write(self, file, encoding="us-ascii"):
653
        assert self._root is not None
654
        if not hasattr(file, "write"):
655
            file = open(file, "wb")
656
        if not encoding:
657
            encoding = "us-ascii"
658
        elif encoding != "utf-8" and encoding != "us-ascii":
659
            file.write("<?xml version='1.0' encoding='%s'?>\n" % encoding)
660
        self._write(file, self._root, encoding, {})
661
662
    def _write(self, file, node, encoding, namespaces):
663
        # write XML to file
664
        tag = node.tag
665
        if tag is Comment:
666
            file.write("<!-- %s -->" % _escape_cdata(node.text, encoding))
667
        elif tag is ProcessingInstruction:
668
            file.write("<?%s?>" % _escape_cdata(node.text, encoding))
669
        else:
670
            items = node.items()
671
            xmlns_items = [] # new namespaces in this scope
672
            try:
673
                if isinstance(tag, QName) or tag[:1] == "{":
674
                    tag, xmlns = fixtag(tag, namespaces)
675
                    if xmlns: xmlns_items.append(xmlns)
676
            except TypeError:
677
                _raise_serialization_error(tag)
678
            file.write("<" + _encode(tag, encoding))
679
            if items or xmlns_items:
680
                items.sort() # lexical order
681
                for k, v in items:
682
                    try:
683
                        if isinstance(k, QName) or k[:1] == "{":
684
                            k, xmlns = fixtag(k, namespaces)
685
                            if xmlns: xmlns_items.append(xmlns)
686
                    except TypeError:
687
                        _raise_serialization_error(k)
688
                    try:
689
                        if isinstance(v, QName):
690
                            v, xmlns = fixtag(v, namespaces)
691
                            if xmlns: xmlns_items.append(xmlns)
692
                    except TypeError:
693
                        _raise_serialization_error(v)
694
                    file.write(" %s=\"%s\"" % (_encode(k, encoding),
695
                                               _escape_attrib(v, encoding)))
696
                for k, v in xmlns_items:
697
                    file.write(" %s=\"%s\"" % (_encode(k, encoding),
698
                                               _escape_attrib(v, encoding)))
314 by Martin Pool
- Update ElementTree to 1.2.6
699
            if node.text or len(node):
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
700
                file.write(">")
701
                if node.text:
702
                    file.write(_escape_cdata(node.text, encoding))
703
                for n in node:
704
                    self._write(file, n, encoding, namespaces)
705
                file.write("</" + _encode(tag, encoding) + ">")
706
            else:
707
                file.write(" />")
708
            for k, v in xmlns_items:
709
                del namespaces[v]
710
        if node.tail:
711
            file.write(_escape_cdata(node.tail, encoding))
712
713
# --------------------------------------------------------------------
714
# helpers
715
716
##
717
# Checks if an object appears to be a valid element object.
718
#
719
# @param An element instance.
720
# @return A true value if this is an element object.
721
# @defreturn flag
722
723
def iselement(element):
724
    # FIXME: not sure about this; might be a better idea to look
725
    # for tag/attrib/text attributes
726
    return isinstance(element, _ElementInterface) or hasattr(element, "tag")
727
728
##
729
# Writes an element tree or element structure to sys.stdout.  This
730
# function should be used for debugging only.
731
# <p>
732
# The exact output format is implementation dependent.  In this
733
# version, it's written as an ordinary XML file.
734
#
735
# @param elem An element tree or an individual element.
736
737
def dump(elem):
738
    # debugging
739
    if not isinstance(elem, ElementTree):
740
        elem = ElementTree(elem)
741
    elem.write(sys.stdout)
742
    tail = elem.getroot().tail
743
    if not tail or tail[-1] != "\n":
744
        sys.stdout.write("\n")
745
746
def _encode(s, encoding):
747
    try:
748
        return s.encode(encoding)
749
    except AttributeError:
750
        return s # 1.5.2: assume the string uses the right encoding
751
752
if sys.version[:3] == "1.5":
753
    _escape = re.compile(r"[&<>\"\x80-\xff]+") # 1.5.2
754
else:
755
    _escape = re.compile(eval(r'u"[&<>\"\u0080-\uffff]+"'))
756
757
_escape_map = {
758
    "&": "&amp;",
759
    "<": "&lt;",
760
    ">": "&gt;",
761
    '"': "&quot;",
762
}
763
764
_namespace_map = {
765
    # "well-known" namespace prefixes
766
    "http://www.w3.org/XML/1998/namespace": "xml",
767
    "http://www.w3.org/1999/xhtml": "html",
768
    "http://www.w3.org/1999/02/22-rdf-syntax-ns#": "rdf",
769
    "http://schemas.xmlsoap.org/wsdl/": "wsdl",
770
}
771
772
def _raise_serialization_error(text):
773
    raise TypeError(
774
        "cannot serialize %r (type %s)" % (text, type(text).__name__)
775
        )
776
777
def _encode_entity(text, pattern=_escape):
778
    # map reserved and non-ascii characters to numerical entities
779
    def escape_entities(m, map=_escape_map):
780
        out = []
781
        append = out.append
782
        for char in m.group():
783
            text = map.get(char)
784
            if text is None:
785
                text = "&#%d;" % ord(char)
786
            append(text)
787
        return string.join(out, "")
788
    try:
789
        return _encode(pattern.sub(escape_entities, text), "ascii")
790
    except TypeError:
791
        _raise_serialization_error(text)
792
793
#
794
# the following functions assume an ascii-compatible encoding
795
# (or "utf-16")
796
797
def _escape_cdata(text, encoding=None, replace=string.replace):
798
    # escape character data
799
    try:
800
        if encoding:
801
            try:
802
                text = _encode(text, encoding)
803
            except UnicodeError:
804
                return _encode_entity(text)
805
        text = replace(text, "&", "&amp;")
806
        text = replace(text, "<", "&lt;")
807
        text = replace(text, ">", "&gt;")
808
        return text
809
    except (TypeError, AttributeError):
810
        _raise_serialization_error(text)
811
812
def _escape_attrib(text, encoding=None, replace=string.replace):
813
    # escape attribute value
814
    try:
815
        if encoding:
816
            try:
817
                text = _encode(text, encoding)
818
            except UnicodeError:
819
                return _encode_entity(text)
820
        text = replace(text, "&", "&amp;")
821
        text = replace(text, "'", "&apos;") # FIXME: overkill
822
        text = replace(text, "\"", "&quot;")
823
        text = replace(text, "<", "&lt;")
824
        text = replace(text, ">", "&gt;")
825
        return text
826
    except (TypeError, AttributeError):
827
        _raise_serialization_error(text)
828
829
def fixtag(tag, namespaces):
830
    # given a decorated tag (of the form {uri}tag), return prefixed
831
    # tag and namespace declaration, if any
832
    if isinstance(tag, QName):
833
        tag = tag.text
834
    namespace_uri, tag = string.split(tag[1:], "}", 1)
835
    prefix = namespaces.get(namespace_uri)
836
    if prefix is None:
837
        prefix = _namespace_map.get(namespace_uri)
838
        if prefix is None:
839
            prefix = "ns%d" % len(namespaces)
840
        namespaces[namespace_uri] = prefix
841
        if prefix == "xml":
842
            xmlns = None
843
        else:
844
            xmlns = ("xmlns:%s" % prefix, namespace_uri)
845
    else:
846
        xmlns = None
847
    return "%s:%s" % (prefix, tag), xmlns
848
849
##
850
# Parses an XML document into an element tree.
851
#
852
# @param source A filename or file object containing XML data.
853
# @param parser An optional parser instance.  If not given, the
854
#     standard {@link XMLTreeBuilder} parser is used.
855
# @return An ElementTree instance
856
857
def parse(source, parser=None):
858
    tree = ElementTree()
859
    tree.parse(source, parser)
860
    return tree
861
862
##
314 by Martin Pool
- Update ElementTree to 1.2.6
863
# Parses an XML document into an element tree incrementally, and reports
864
# what's going on to the user.
865
#
866
# @param source A filename or file object containing XML data.
867
# @param events A list of events to report back.  If omitted, only "end"
868
#     events are reported.
869
# @return A (event, elem) iterator.
870
871
class iterparse:
872
873
    def __init__(self, source, events=None):
874
        if not hasattr(source, "read"):
875
            source = open(source, "rb")
876
        self._file = source
877
        self._events = []
878
        self._index = 0
879
        self.root = self._root = None
880
        self._parser = XMLTreeBuilder()
881
        # wire up the parser for event reporting
882
        parser = self._parser._parser
883
        append = self._events.append
884
        if events is None:
885
            events = ["end"]
886
        for event in events:
887
            if event == "start":
888
                try:
889
                    parser.ordered_attributes = 1
890
                    parser.specified_attributes = 1
891
                    def handler(tag, attrib_in, event=event, append=append,
892
                                start=self._parser._start_list):
893
                        append((event, start(tag, attrib_in)))
894
                    parser.StartElementHandler = handler
895
                except AttributeError:
896
                    def handler(tag, attrib_in, event=event, append=append,
897
                                start=self._parser._start):
898
                        append((event, start(tag, attrib_in)))
899
                    parser.StartElementHandler = handler
900
            elif event == "end":
901
                def handler(tag, event=event, append=append,
902
                            end=self._parser._end):
903
                    append((event, end(tag)))
904
                parser.EndElementHandler = handler
905
            elif event == "start-ns":
906
                def handler(prefix, uri, event=event, append=append):
907
                    try:
908
                        uri = _encode(uri, "ascii")
909
                    except UnicodeError:
910
                        pass
911
                    append((event, (prefix or "", uri)))
912
                parser.StartNamespaceDeclHandler = handler
913
            elif event == "end-ns":
914
                def handler(prefix, event=event, append=append):
915
                    append((event, None))
916
                parser.EndNamespaceDeclHandler = handler
917
918
    def next(self):
919
        while 1:
920
            try:
921
                item = self._events[self._index]
922
            except IndexError:
923
                if self._parser is None:
924
                    self.root = self._root
925
                    try:
926
                        raise StopIteration
927
                    except NameError:
928
                        raise IndexError
929
                # load event buffer
930
                del self._events[:]
931
                self._index = 0
932
                data = self._file.read(16384)
933
                if data:
934
                    self._parser.feed(data)
935
                else:
936
                    self._root = self._parser.close()
937
                    self._parser = None
938
            else:
939
                self._index = self._index + 1
940
                return item
941
942
    try:
943
        iter
944
        def __iter__(self):
945
            return self
946
    except NameError:
947
        def __getitem__(self, index):
948
            return self.next()
949
950
##
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
951
# Parses an XML document from a string constant.  This function can
952
# be used to embed "XML literals" in Python code.
953
#
954
# @param source A string containing XML data.
955
# @return An Element instance.
956
# @defreturn Element
957
958
def XML(text):
959
    parser = XMLTreeBuilder()
960
    parser.feed(text)
961
    return parser.close()
962
963
##
964
# Parses an XML document from a string constant, and also returns
965
# a dictionary which maps from element id:s to elements.
966
#
967
# @param source A string containing XML data.
968
# @return A tuple containing an Element instance and a dictionary.
969
# @defreturn (Element, dictionary)
970
971
def XMLID(text):
972
    parser = XMLTreeBuilder()
973
    parser.feed(text)
974
    tree = parser.close()
975
    ids = {}
976
    for elem in tree.getiterator():
977
        id = elem.get("id")
978
        if id:
979
            ids[id] = elem
980
    return tree, ids
981
982
##
983
# Parses an XML document from a string constant.  Same as {@link #XML}.
984
#
985
# @def fromstring(text)
986
# @param source A string containing XML data.
987
# @return An Element instance.
988
# @defreturn Element
989
990
fromstring = XML
991
992
##
993
# Generates a string representation of an XML element, including all
994
# subelements.
995
#
996
# @param element An Element instance.
997
# @return An encoded string containing the XML data.
998
# @defreturn string
999
1000
def tostring(element, encoding=None):
1001
    class dummy:
1002
        pass
1003
    data = []
1004
    file = dummy()
1005
    file.write = data.append
1006
    ElementTree(element).write(file, encoding)
1007
    return string.join(data, "")
1008
1009
##
1010
# Generic element structure builder.  This builder converts a sequence
1011
# of {@link #TreeBuilder.start}, {@link #TreeBuilder.data}, and {@link
1012
# #TreeBuilder.end} method calls to a well-formed element structure.
1013
# <p>
1014
# You can use this class to build an element structure using a custom XML
1015
# parser, or a parser for some other XML-like format.
1016
#
1017
# @param element_factory Optional element factory.  This factory
1018
#    is called to create new Element instances, as necessary.
1019
1020
class TreeBuilder:
1021
1022
    def __init__(self, element_factory=None):
1023
        self._data = [] # data collector
1024
        self._elem = [] # element stack
1025
        self._last = None # last element
1026
        self._tail = None # true if we're after an end tag
1027
        if element_factory is None:
1028
            element_factory = _ElementInterface
1029
        self._factory = element_factory
1030
1031
    ##
1032
    # Flushes the parser buffers, and returns the toplevel documen
1033
    # element.
1034
    #
1035
    # @return An Element instance.
1036
    # @defreturn Element
1037
1038
    def close(self):
1039
        assert len(self._elem) == 0, "missing end tags"
1040
        assert self._last != None, "missing toplevel element"
1041
        return self._last
1042
1043
    def _flush(self):
1044
        if self._data:
1045
            if self._last is not None:
1046
                text = string.join(self._data, "")
1047
                if self._tail:
1048
                    assert self._last.tail is None, "internal error (tail)"
1049
                    self._last.tail = text
1050
                else:
1051
                    assert self._last.text is None, "internal error (text)"
1052
                    self._last.text = text
1053
            self._data = []
1054
1055
    ##
1056
    # Adds text to the current element.
1057
    #
1058
    # @param data A string.  This should be either an 8-bit string
1059
    #    containing ASCII text, or a Unicode string.
1060
1061
    def data(self, data):
1062
        self._data.append(data)
1063
1064
    ##
1065
    # Opens a new element.
1066
    #
1067
    # @param tag The element name.
1068
    # @param attrib A dictionary containing element attributes.
1069
    # @return The opened element.
1070
    # @defreturn Element
1071
1072
    def start(self, tag, attrs):
1073
        self._flush()
1074
        self._last = elem = self._factory(tag, attrs)
1075
        if self._elem:
1076
            self._elem[-1].append(elem)
1077
        self._elem.append(elem)
1078
        self._tail = 0
1079
        return elem
1080
1081
    ##
1082
    # Closes the current element.
1083
    #
1084
    # @param tag The element name.
1085
    # @return The closed element.
1086
    # @defreturn Element
1087
1088
    def end(self, tag):
1089
        self._flush()
1090
        self._last = self._elem.pop()
1091
        assert self._last.tag == tag,\
1092
               "end tag mismatch (expected %s, got %s)" % (
1093
                   self._last.tag, tag)
1094
        self._tail = 1
1095
        return self._last
1096
1097
##
1098
# Element structure builder for XML source data, based on the
1099
# <b>expat</b> parser.
1100
#
1101
# @keyparam target Target object.  If omitted, the builder uses an
1102
#     instance of the standard {@link #TreeBuilder} class.
1103
# @keyparam html Predefine HTML entities.  This flag is not supported
1104
#     by the current implementation.
1105
# @see #ElementTree
1106
# @see #TreeBuilder
1107
1108
class XMLTreeBuilder:
1109
1110
    def __init__(self, html=0, target=None):
314 by Martin Pool
- Update ElementTree to 1.2.6
1111
        try:
1112
            from xml.parsers import expat
1113
        except ImportError:
1114
            raise ImportError(
1115
                "No module named expat; use SimpleXMLTreeBuilder instead"
1116
                )
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
1117
        self._parser = parser = expat.ParserCreate(None, "}")
1118
        if target is None:
1119
            target = TreeBuilder()
1120
        self._target = target
1121
        self._names = {} # name memo cache
314 by Martin Pool
- Update ElementTree to 1.2.6
1122
        # callbacks
1123
        parser.DefaultHandlerExpand = self._default
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
1124
        parser.StartElementHandler = self._start
1125
        parser.EndElementHandler = self._end
1126
        parser.CharacterDataHandler = self._data
314 by Martin Pool
- Update ElementTree to 1.2.6
1127
        # let expat do the buffering, if supported
1128
        try:
1129
            self._parser.buffer_text = 1
1130
        except AttributeError:
1131
            pass
1132
        # use new-style attribute handling, if supported
1133
        try:
1134
            self._parser.ordered_attributes = 1
1135
            self._parser.specified_attributes = 1
1136
            parser.StartElementHandler = self._start_list
1137
        except AttributeError:
1138
            pass
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
1139
        encoding = None
1140
        if not parser.returns_unicode:
1141
            encoding = "utf-8"
1142
        # target.xml(encoding, None)
1143
        self._doctype = None
1144
        self.entity = {}
1145
1146
    def _fixtext(self, text):
1147
        # convert text string to ascii, if possible
1148
        try:
314 by Martin Pool
- Update ElementTree to 1.2.6
1149
            return _encode(text, "ascii")
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
1150
        except UnicodeError:
1151
            return text
1152
1153
    def _fixname(self, key):
1154
        # expand qname, and convert name string to ascii, if possible
1155
        try:
1156
            name = self._names[key]
1157
        except KeyError:
1158
            name = key
1159
            if "}" in name:
1160
                name = "{" + name
1161
            self._names[key] = name = self._fixtext(name)
1162
        return name
1163
1164
    def _start(self, tag, attrib_in):
1165
        fixname = self._fixname
1166
        tag = fixname(tag)
1167
        attrib = {}
1168
        for key, value in attrib_in.items():
1169
            attrib[fixname(key)] = self._fixtext(value)
1170
        return self._target.start(tag, attrib)
1171
314 by Martin Pool
- Update ElementTree to 1.2.6
1172
    def _start_list(self, tag, attrib_in):
1173
        fixname = self._fixname
1174
        tag = fixname(tag)
1175
        attrib = {}
1176
        if attrib_in:
1177
            for i in range(0, len(attrib_in), 2):
1178
                attrib[fixname(attrib_in[i])] = self._fixtext(attrib_in[i+1])
1179
        return self._target.start(tag, attrib)
1180
72 by mbp at sourcefrog
- import a subset of elementtree for easier installation
1181
    def _data(self, text):
1182
        return self._target.data(self._fixtext(text))
1183
1184
    def _end(self, tag):
1185
        return self._target.end(self._fixname(tag))
1186
1187
    def _default(self, text):
1188
        prefix = text[:1]
1189
        if prefix == "&":
1190
            # deal with undefined entities
1191
            try:
1192
                self._target.data(self.entity[text[1:-1]])
1193
            except KeyError:
1194
                from xml.parsers import expat
1195
                raise expat.error(
1196
                    "undefined entity %s: line %d, column %d" %
1197
                    (text, self._parser.ErrorLineNumber,
1198
                    self._parser.ErrorColumnNumber)
1199
                    )
1200
        elif prefix == "<" and text[:9] == "<!DOCTYPE":
1201
            self._doctype = [] # inside a doctype declaration
1202
        elif self._doctype is not None:
1203
            # parse doctype contents
1204
            if prefix == ">":
1205
                self._doctype = None
1206
                return
1207
            text = string.strip(text)
1208
            if not text:
1209
                return
1210
            self._doctype.append(text)
1211
            n = len(self._doctype)
1212
            if n > 2:
1213
                type = self._doctype[1]
1214
                if type == "PUBLIC" and n == 4:
1215
                    name, type, pubid, system = self._doctype
1216
                elif type == "SYSTEM" and n == 3:
1217
                    name, type, system = self._doctype
1218
                    pubid = None
1219
                else:
1220
                    return
1221
                if pubid:
1222
                    pubid = pubid[1:-1]
1223
                self.doctype(name, pubid, system[1:-1])
1224
                self._doctype = None
1225
1226
    ##
1227
    # Handles a doctype declaration.
1228
    #
1229
    # @param name Doctype name.
1230
    # @param pubid Public identifier.
1231
    # @param system System identifier.
1232
1233
    def doctype(self, name, pubid, system):
1234
        pass
1235
1236
    ##
1237
    # Feeds data to the parser.
1238
    #
1239
    # @param data Encoded data.
1240
1241
    def feed(self, data):
1242
        self._parser.Parse(data, 0)
1243
1244
    ##
1245
    # Finishes feeding data to the parser.
1246
    #
1247
    # @return An element structure.
1248
    # @defreturn Element
1249
1250
    def close(self):
1251
        self._parser.Parse("", 1) # end of data
1252
        tree = self._target.close()
1253
        del self._target, self._parser # get rid of circular references
1254
        return tree