3
# $Id: ElementTree.py 2326 2005-03-17 07:45:21Z fredrik $
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# light-weight XML support for Python 1.5.2 and later.
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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
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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
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# Copyright (c) 1999-2005 by Fredrik Lundh. All rights reserved.
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# fredrik@pythonware.com
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# http://www.pythonware.com
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# --------------------------------------------------------------------
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# The ElementTree toolkit is
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# Copyright (c) 1999-2005 by Fredrik Lundh
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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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# 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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# 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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# --------------------------------------------------------------------
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"Element", "ElementTree",
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"iselement", "iterparse",
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"PI", "ProcessingInstruction",
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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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# Each element has a number of properties associated with it:
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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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# To create an element instance, use the {@link #Element} or {@link
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# #SubElement} factory functions.
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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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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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def findtext(self, element, tag, default=None):
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return elem.text or ""
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def findall(self, element, tag):
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return element.getiterator(tag[3:])
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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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# 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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# 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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# @see ProcessingInstruction
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class _ElementInterface:
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# <tag attrib>text<child/>...</tag>tail
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# (Attribute) Element tag.
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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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# (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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# (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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return "<Element %s at %x>" % (self.tag, id(self))
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# Creates a new element object of the same type as this element.
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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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# Returns the number of subelements.
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# @return The number of subelements.
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return len(self._children)
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# Returns the given subelement.
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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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# Replaces the given subelement.
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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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# Deletes the given subelement.
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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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# Returns a list containing subelements in the given range.
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# @param start The first subelement to return.
248
# @param stop The first subelement that shouldn't be returned.
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# @return A sequence object containing subelements.
251
def __getslice__(self, start, stop):
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return self._children[start:stop]
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# Replaces a number of subelements with elements from a sequence.
257
# @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.
262
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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# Deletes a number of subelements.
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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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# Adds a subelement to the end of this element.
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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.
282
def append(self, element):
283
assert iselement(element)
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self._children.append(element)
287
# Inserts a subelement at the given position in this element.
289
# @param index Where to insert the new subelement.
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# @exception AssertionError If the element is not a valid object.
292
def insert(self, index, element):
293
assert iselement(element)
294
self._children.insert(index, element)
297
# Removes a matching subelement. Unlike the <b>find</b> methods,
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# this method compares elements based on identity, not on tag
301
# @param element What element to remove.
302
# @exception ValueError If a matching element could not be found.
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# @exception AssertionError If the element is not a valid object.
305
def remove(self, element):
306
assert iselement(element)
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self._children.remove(element)
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# Returns all subelements. The elements are returned in document
313
# @return A list of subelements.
314
# @defreturn list of Element instances
316
def getchildren(self):
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return self._children
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# Finds the first matching subelement, by tag name or path.
322
# @param path What element to look for.
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# @return The first matching element, or None if no element was found.
324
# @defreturn Element or None
326
def find(self, path):
327
return ElementPath.find(self, path)
330
# Finds text for the first matching subelement, by tag name or path.
332
# @param path What element to look for.
333
# @param default What to return if the element was not found.
334
# @return The text content of the first matching element, or the
335
# default value no element was found. Note that if the element
336
# has is found, but has no text content, this method returns an
340
def findtext(self, path, default=None):
341
return ElementPath.findtext(self, path, default)
344
# Finds all matching subelements, by tag name or path.
346
# @param path What element to look for.
347
# @return A list or iterator containing all matching elements,
349
# @defreturn list of Element instances
351
def findall(self, path):
352
return ElementPath.findall(self, path)
355
# Resets an element. This function removes all subelements, clears
356
# all attributes, and sets the text and tail attributes to None.
361
self.text = self.tail = None
364
# Gets an element attribute.
366
# @param key What attribute to look for.
367
# @param default What to return if the attribute was not found.
368
# @return The attribute value, or the default value, if the
369
# attribute was not found.
370
# @defreturn string or None
372
def get(self, key, default=None):
373
return self.attrib.get(key, default)
376
# Sets an element attribute.
378
# @param key What attribute to set.
379
# @param value The attribute value.
381
def set(self, key, value):
382
self.attrib[key] = value
385
# Gets a list of attribute names. The names are returned in an
386
# arbitrary order (just like for an ordinary Python dictionary).
388
# @return A list of element attribute names.
389
# @defreturn list of strings
392
return self.attrib.keys()
395
# Gets element attributes, as a sequence. The attributes are
396
# returned in an arbitrary order.
398
# @return A list of (name, value) tuples for all attributes.
399
# @defreturn list of (string, string) tuples
402
return self.attrib.items()
405
# Creates a tree iterator. The iterator loops over this element
406
# and all subelements, in document order, and returns all elements
407
# with a matching tag.
409
# If the tree structure is modified during iteration, the result
412
# @param tag What tags to look for (default is to return all elements).
413
# @return A list or iterator containing all the matching elements.
414
# @defreturn list or iterator
416
def getiterator(self, tag=None):
420
if tag is None or self.tag == tag:
422
for node in self._children:
423
nodes.extend(node.getiterator(tag))
427
_Element = _ElementInterface
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.
435
# The element name, attribute names, and attribute values can be
436
# either 8-bit ASCII strings or Unicode strings.
438
# @param tag The element name.
439
# @param attrib An optional dictionary, containing element attributes.
440
# @param **extra Additional attributes, given as keyword arguments.
441
# @return An element instance.
444
def Element(tag, attrib={}, **extra):
445
attrib = attrib.copy()
447
return _ElementInterface(tag, attrib)
450
# Subelement factory. This function creates an element instance, and
451
# appends it to an existing element.
453
# The element name, attribute names, and attribute values can be
454
# either 8-bit ASCII strings or Unicode strings.
456
# @param parent The parent element.
457
# @param tag The subelement name.
458
# @param attrib An optional dictionary, containing element attributes.
459
# @param **extra Additional attributes, given as keyword arguments.
460
# @return An element instance.
463
def SubElement(parent, tag, attrib={}, **extra):
464
attrib = attrib.copy()
466
element = parent.makeelement(tag, attrib)
467
parent.append(element)
471
# Comment element factory. This factory function creates a special
472
# element that will be serialized as an XML comment.
474
# The comment string can be either an 8-bit ASCII string or a Unicode
477
# @param text A string containing the comment string.
478
# @return An element instance, representing a comment.
481
def Comment(text=None):
482
element = Element(Comment)
487
# PI element factory. This factory function creates a special element
488
# that will be serialized as an XML processing instruction.
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.
495
def ProcessingInstruction(target, text=None):
496
element = Element(ProcessingInstruction)
497
element.text = target
499
element.text = element.text + " " + text
502
PI = ProcessingInstruction
505
# QName wrapper. This can be used to wrap a QName attribute value, in
506
# order to get proper namespace handling on output.
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.
515
def __init__(self, text_or_uri, tag=None):
517
text_or_uri = "{%s}%s" % (text_or_uri, tag)
518
self.text = text_or_uri
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)
529
# ElementTree wrapper class. This class represents an entire element
530
# hierarchy, and adds some extra support for serialization to and from
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.
539
def __init__(self, element=None, file=None):
540
assert element is None or iselement(element)
541
self._root = element # first node
546
# Gets the root element for this tree.
548
# @return An element instance.
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.
559
# @param element An element instance.
561
def _setroot(self, element):
562
assert iselement(element)
566
# Loads an external XML document into this element tree.
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.
574
def parse(self, source, parser=None):
575
if not hasattr(source, "read"):
576
source = open(source, "rb")
578
parser = XMLTreeBuilder()
580
data = source.read(32768)
584
self._root = parser.close()
588
# Creates a tree iterator for the root element. The iterator loops
589
# over all elements in this tree, in document order.
591
# @param tag What tags to look for (default is to return all elements)
592
# @return An iterator.
593
# @defreturn iterator
595
def getiterator(self, tag=None):
596
assert self._root is not None
597
return self._root.getiterator(tag)
600
# Finds the first toplevel element with given tag.
601
# Same as getroot().find(path).
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
607
def find(self, path):
608
assert self._root is not None
611
return self._root.find(path)
614
# Finds the element text for the first toplevel element with given
615
# tag. Same as getroot().findtext(path).
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
625
def findtext(self, path, default=None):
626
assert self._root is not None
629
return self._root.findtext(path, default)
632
# Finds all toplevel elements with the given tag.
633
# Same as getroot().findall(path).
635
# @param path What element to look for.
636
# @return A list or iterator containing all matching elements,
638
# @defreturn list of Element instances
640
def findall(self, path):
641
assert self._root is not None
644
return self._root.findall(path)
647
# Writes the element tree to a file, as XML.
649
# @param file A file name, or a file object opened for writing.
650
# @param encoding Optional output encoding (default is US-ASCII).
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")
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, {})
662
def _write(self, file, node, encoding, namespaces):
666
file.write("<!-- %s -->" % _escape_cdata(node.text, encoding))
667
elif tag is ProcessingInstruction:
668
file.write("<?%s?>" % _escape_cdata(node.text, encoding))
671
xmlns_items = [] # new namespaces in this scope
673
if isinstance(tag, QName) or tag[:1] == "{":
674
tag, xmlns = fixtag(tag, namespaces)
675
if xmlns: xmlns_items.append(xmlns)
677
_raise_serialization_error(tag)
678
file.write("<" + _encode(tag, encoding))
679
if items or xmlns_items:
680
items.sort() # lexical order
683
if isinstance(k, QName) or k[:1] == "{":
684
k, xmlns = fixtag(k, namespaces)
685
if xmlns: xmlns_items.append(xmlns)
687
_raise_serialization_error(k)
689
if isinstance(v, QName):
690
v, xmlns = fixtag(v, namespaces)
691
if xmlns: xmlns_items.append(xmlns)
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)))
699
if node.text or len(node):
702
file.write(_escape_cdata(node.text, encoding))
704
self._write(file, n, encoding, namespaces)
705
file.write("</" + _encode(tag, encoding) + ">")
708
for k, v in xmlns_items:
711
file.write(_escape_cdata(node.tail, encoding))
713
# --------------------------------------------------------------------
717
# Checks if an object appears to be a valid element object.
719
# @param An element instance.
720
# @return A true value if this is an element object.
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")
729
# Writes an element tree or element structure to sys.stdout. This
730
# function should be used for debugging only.
732
# The exact output format is implementation dependent. In this
733
# version, it's written as an ordinary XML file.
735
# @param elem An element tree or an individual element.
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")
746
def _encode(s, encoding):
748
return s.encode(encoding)
749
except AttributeError:
750
return s # 1.5.2: assume the string uses the right encoding
752
if sys.version[:3] == "1.5":
753
_escape = re.compile(r"[&<>\"\x80-\xff]+") # 1.5.2
755
_escape = re.compile(eval(r'u"[&<>\"\u0080-\uffff]+"'))
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",
772
def _raise_serialization_error(text):
774
"cannot serialize %r (type %s)" % (text, type(text).__name__)
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):
782
for char in m.group():
785
text = "&#%d;" % ord(char)
787
return string.join(out, "")
789
return _encode(pattern.sub(escape_entities, text), "ascii")
791
_raise_serialization_error(text)
794
# the following functions assume an ascii-compatible encoding
797
def _escape_cdata(text, encoding=None, replace=string.replace):
798
# escape character data
802
text = _encode(text, encoding)
804
return _encode_entity(text)
805
text = replace(text, "&", "&")
806
text = replace(text, "<", "<")
807
text = replace(text, ">", ">")
809
except (TypeError, AttributeError):
810
_raise_serialization_error(text)
812
def _escape_attrib(text, encoding=None, replace=string.replace):
813
# escape attribute value
817
text = _encode(text, encoding)
819
return _encode_entity(text)
820
text = replace(text, "&", "&")
821
text = replace(text, "'", "'") # FIXME: overkill
822
text = replace(text, "\"", """)
823
text = replace(text, "<", "<")
824
text = replace(text, ">", ">")
826
except (TypeError, AttributeError):
827
_raise_serialization_error(text)
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):
834
namespace_uri, tag = string.split(tag[1:], "}", 1)
835
prefix = namespaces.get(namespace_uri)
837
prefix = _namespace_map.get(namespace_uri)
839
prefix = "ns%d" % len(namespaces)
840
namespaces[namespace_uri] = prefix
844
xmlns = ("xmlns:%s" % prefix, namespace_uri)
847
return "%s:%s" % (prefix, tag), xmlns
850
# Parses an XML document into an element tree.
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
857
def parse(source, parser=None):
859
tree.parse(source, parser)
863
# Parses an XML document into an element tree incrementally, and reports
864
# what's going on to the user.
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.
873
def __init__(self, source, events=None):
874
if not hasattr(source, "read"):
875
source = open(source, "rb")
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
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
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):
908
uri = _encode(uri, "ascii")
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
921
item = self._events[self._index]
923
if self._parser is None:
924
self.root = self._root
932
data = self._file.read(16384)
934
self._parser.feed(data)
936
self._root = self._parser.close()
939
self._index = self._index + 1
947
def __getitem__(self, index):
951
# Parses an XML document from a string constant. This function can
952
# be used to embed "XML literals" in Python code.
954
# @param source A string containing XML data.
955
# @return An Element instance.
959
parser = XMLTreeBuilder()
961
return parser.close()
964
# Parses an XML document from a string constant, and also returns
965
# a dictionary which maps from element id:s to elements.
967
# @param source A string containing XML data.
968
# @return A tuple containing an Element instance and a dictionary.
969
# @defreturn (Element, dictionary)
972
parser = XMLTreeBuilder()
974
tree = parser.close()
976
for elem in tree.getiterator():
983
# Parses an XML document from a string constant. Same as {@link #XML}.
985
# @def fromstring(text)
986
# @param source A string containing XML data.
987
# @return An Element instance.
993
# Generates a string representation of an XML element, including all
996
# @param element An Element instance.
997
# @return An encoded string containing the XML data.
1000
def tostring(element, encoding=None):
1005
file.write = data.append
1006
ElementTree(element).write(file, encoding)
1007
return string.join(data, "")
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.
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.
1017
# @param element_factory Optional element factory. This factory
1018
# is called to create new Element instances, as necessary.
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
1032
# Flushes the parser buffers, and returns the toplevel documen
1035
# @return An Element instance.
1036
# @defreturn Element
1039
assert len(self._elem) == 0, "missing end tags"
1040
assert self._last != None, "missing toplevel element"
1045
if self._last is not None:
1046
text = string.join(self._data, "")
1048
assert self._last.tail is None, "internal error (tail)"
1049
self._last.tail = text
1051
assert self._last.text is None, "internal error (text)"
1052
self._last.text = text
1056
# Adds text to the current element.
1058
# @param data A string. This should be either an 8-bit string
1059
# containing ASCII text, or a Unicode string.
1061
def data(self, data):
1062
self._data.append(data)
1065
# Opens a new element.
1067
# @param tag The element name.
1068
# @param attrib A dictionary containing element attributes.
1069
# @return The opened element.
1070
# @defreturn Element
1072
def start(self, tag, attrs):
1074
self._last = elem = self._factory(tag, attrs)
1076
self._elem[-1].append(elem)
1077
self._elem.append(elem)
1082
# Closes the current element.
1084
# @param tag The element name.
1085
# @return The closed element.
1086
# @defreturn Element
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)
1098
# Element structure builder for XML source data, based on the
1099
# <b>expat</b> parser.
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.
1108
class XMLTreeBuilder:
1110
def __init__(self, html=0, target=None):
1112
from xml.parsers import expat
1115
"No module named expat; use SimpleXMLTreeBuilder instead"
1117
self._parser = parser = expat.ParserCreate(None, "}")
1119
target = TreeBuilder()
1120
self._target = target
1121
self._names = {} # name memo cache
1123
parser.DefaultHandlerExpand = self._default
1124
parser.StartElementHandler = self._start
1125
parser.EndElementHandler = self._end
1126
parser.CharacterDataHandler = self._data
1127
# let expat do the buffering, if supported
1129
self._parser.buffer_text = 1
1130
except AttributeError:
1132
# use new-style attribute handling, if supported
1134
self._parser.ordered_attributes = 1
1135
self._parser.specified_attributes = 1
1136
parser.StartElementHandler = self._start_list
1137
except AttributeError:
1140
if not parser.returns_unicode:
1142
# target.xml(encoding, None)
1143
self._doctype = None
1146
def _fixtext(self, text):
1147
# convert text string to ascii, if possible
1149
return _encode(text, "ascii")
1150
except UnicodeError:
1153
def _fixname(self, key):
1154
# expand qname, and convert name string to ascii, if possible
1156
name = self._names[key]
1161
self._names[key] = name = self._fixtext(name)
1164
def _start(self, tag, attrib_in):
1165
fixname = self._fixname
1168
for key, value in attrib_in.items():
1169
attrib[fixname(key)] = self._fixtext(value)
1170
return self._target.start(tag, attrib)
1172
def _start_list(self, tag, attrib_in):
1173
fixname = self._fixname
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)
1181
def _data(self, text):
1182
return self._target.data(self._fixtext(text))
1184
def _end(self, tag):
1185
return self._target.end(self._fixname(tag))
1187
def _default(self, text):
1190
# deal with undefined entities
1192
self._target.data(self.entity[text[1:-1]])
1194
from xml.parsers import expat
1196
"undefined entity %s: line %d, column %d" %
1197
(text, self._parser.ErrorLineNumber,
1198
self._parser.ErrorColumnNumber)
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
1205
self._doctype = None
1207
text = string.strip(text)
1210
self._doctype.append(text)
1211
n = len(self._doctype)
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
1223
self.doctype(name, pubid, system[1:-1])
1224
self._doctype = None
1227
# Handles a doctype declaration.
1229
# @param name Doctype name.
1230
# @param pubid Public identifier.
1231
# @param system System identifier.
1233
def doctype(self, name, pubid, system):
1237
# Feeds data to the parser.
1239
# @param data Encoded data.
1241
def feed(self, data):
1242
self._parser.Parse(data, 0)
1245
# Finishes feeding data to the parser.
1247
# @return An element structure.
1248
# @defreturn Element
1251
self._parser.Parse("", 1) # end of data
1252
tree = self._target.close()
1253
del self._target, self._parser # get rid of circular references
added
removed
elementtree/ElementTree.py
