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