ncclient:NETCONF Python client

Homepage: http://oss.schmizz.net/ncclient

* Paramiko 1.7.4+

#

# ElementTree

# $Id: ElementTree.py 3224 2007-08-27 21:23:39Z fredrik $

#

# light-weight XML support for Python 1.5.2 and later.

#

# history:

# 2001-10-20 fl   created (from various sources)

# 2001-11-01 fl   return root from parse method

# 2002-02-16 fl   sort attributes in lexical order

# 2002-04-06 fl   TreeBuilder refactoring, added PythonDoc markup

# 2002-05-01 fl   finished TreeBuilder refactoring

# 2002-07-14 fl   added basic namespace support to ElementTree.write

# 2002-07-25 fl   added QName attribute support

# 2002-10-20 fl   fixed encoding in write

# 2002-11-24 fl   changed default encoding to ascii; fixed attribute encoding

# 2002-11-27 fl   accept file objects or file names for parse/write

# 2002-12-04 fl   moved XMLTreeBuilder back to this module

# 2003-01-11 fl   fixed entity encoding glitch for us-ascii

# 2003-02-13 fl   added XML literal factory

# 2003-02-21 fl   added ProcessingInstruction/PI factory

# 2003-05-11 fl   added tostring/fromstring helpers

# 2003-05-26 fl   added ElementPath support

# 2003-07-05 fl   added makeelement factory method

# 2003-07-28 fl   added more well-known namespace prefixes

# 2003-08-15 fl   fixed typo in ElementTree.findtext (Thomas Dartsch)

# 2003-09-04 fl   fall back on emulator if ElementPath is not installed

# 2003-10-31 fl   markup updates

# 2003-11-15 fl   fixed nested namespace bug

# 2004-03-28 fl   added XMLID helper

# 2004-06-02 fl   added default support to findtext

# 2004-06-08 fl   fixed encoding of non-ascii element/attribute names

# 2004-08-23 fl   take advantage of post-2.1 expat features

# 2005-02-01 fl   added iterparse implementation

# 2005-03-02 fl   fixed iterparse support for pre-2.2 versions

# 2006-11-18 fl   added parser support for IronPython (ElementIron)

# 2007-08-27 fl   fixed newlines in attributes

#

# Copyright (c) 1999-2007 by Fredrik Lundh.  All rights reserved.

#

# fredrik@pythonware.com

# http://www.pythonware.com

#

# --------------------------------------------------------------------

# The ElementTree toolkit is

#

# Copyright (c) 1999-2007 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.

# --------------------------------------------------------------------

__all__ = [

    # public symbols

    "Comment",

    "dump",

    "Element", "ElementTree",

    "fromstring",

    "iselement", "iterparse",

    "parse",

    "PI", "ProcessingInstruction",

    "QName",

    "SubElement",

    "tostring",

    "TreeBuilder",

    "VERSION", "XML",

    "XMLTreeBuilder",

    ]

# parser api override (None = use default)

parser_api = None

# TODO: add support for custom namespace resolvers/default namespaces

# TODO: add improved support for incremental parsing

VERSION = "1.2.7"

##

# 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} or {@link

# #SubElement} factory functions.

# <p>

# The {@link #ElementTree} class can be used to wrap an element

# structure, and convert it from and to XML.

##

import sys, re

try:

    import string

except:

    # emulate string module under IronPython

    class string(object):

        def join(self, seq, sep):

            return sep.join(seq)

        def replace(self, text, *args):

            return text.replace(*args)

        def split(self, text, *args):

            return text.split(*args)

        def strip(self, text, *args):

            return text.strip(*args)

    string = string()

class _SimpleElementPath:

    # emulate pre-1.2 find/findtext/findall behaviour

    def find(self, element, tag):

        for elem in element:

            if elem.tag == tag:

                return elem

        return None

    def findtext(self, element, tag, default=None):

        for elem in element:

            if elem.tag == tag:

                return elem.text or ""

        return default

    def findall(self, element, tag):

        if tag[:3] == ".//":

            return element.getiterator(tag[3:])

        result = []

        for elem in element:

            if elem.tag == tag:

                result.append(elem)

        return result

try:

    import ElementPath

except ImportError:

    # FIXME: issue warning in this case?

    ElementPath = _SimpleElementPath()

class DefaultParserAPI:

    def parse(self, source, parser=None):

        if not hasattr(source, "read"):

            source = open(source, "rb")

        if not parser:

            parser = XMLTreeBuilder()

        while 1:

            data = source.read(32768)

            if not data:

                break

            parser.feed(data)

        return parser.close()

    def iterparse(self, source, events):

        return _iterparse(source, events)

    def fromstring(self, text):

        parser = XMLTreeBuilder()

        parser.feed(text)

        return parser.close()

parser_api = default_parser_api = DefaultParserAPI()

##

# Internal element class.  This class defines the Element interface,

# and provides a reference implementation of this interface.

# <p>

# You should not create instances of this class directly.  Use the

# appropriate factory functions instead, such as {@link #Element}

# and {@link #SubElement}.

#

# @see Element

# @see SubElement

# @see Comment

# @see ProcessingInstruction

class _ElementInterface:

    # <tag attrib>text<child/>...</tag>tail

    ##

    # (Attribute) Element tag.

    tag = None

    ##

    # (Attribute) Element attribute dictionary.  Where possible, use

    # {@link #_ElementInterface.get},

    # {@link #_ElementInterface.set},

    # {@link #_ElementInterface.keys}, and

    # {@link #_ElementInterface.items} to access

    # element attributes.

    attrib = None

    ##

    # (Attribute) Text before first subelement.  This is either a

    # string or the value None, if there was no text.

    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, if there was no text.

    tail = None # text after end tag, if any

    def __init__(self, tag, attrib):

        self.tag = tag

        self.attrib = attrib

        self._children = []

    def __repr__(self):

        return "<Element %s at %x>" % (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 Element(tag, attrib)

    ##

    # Returns the number of subelements.

    #

    # @return The number of subelements.

    def __len__(self):

        return len(self._children)

    ##

    # Returns the given subelement.

    #

    # @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.

    #

    # @param index What subelement to replace.

    # @param element The new element value.

    # @exception IndexError If the given element does not exist.

    # @exception AssertionError If element is not a valid object.

    def __setitem__(self, index, element):

        assert iselement(element)

        self._children[index] = element

    ##

    # Deletes the given subelement.

    #

    # @param index What subelement to delete.

    # @exception IndexError If the given element does not exist.

    def __delitem__(self, index):

        del self._children[index]

    ##

    # Returns a list containing subelements in the given range.

    #

    # @param start The first subelement to return.

    # @param stop The first subelement that shouldn't be returned.

    # @return A sequence object containing subelements.

    def __getslice__(self, start, stop):

        return self._children[start:stop]

    ##

    # Replaces a number of subelements with elements from a sequence.

    #

    # @param start The first subelement to replace.

    # @param stop The first subelement that shouldn't be replaced.

    # @param elements A sequence object with zero or more elements.

    # @exception AssertionError If a sequence member is not a valid object.

    def __setslice__(self, start, stop, elements):

        for element in elements:

            assert iselement(element)

        self._children[start:stop] = list(elements)

    ##

    # Deletes a number of subelements.

    #

    # @param start The first subelement to delete.

    # @param stop The first subelement to leave in there.

    def __delslice__(self, start, stop):

        del self._children[start:stop]

    ##

    # Adds a subelement to the end of this element.

    #

    # @param element The element to add.

    # @exception AssertionError If a sequence member is not a valid object.

    def append(self, element):

        assert iselement(element)

        self._children.append(element)

    ##

    # Inserts a subelement at the given position in this element.

    #

    # @param index Where to insert the new subelement.

    # @exception AssertionError If the element is not a valid object.

    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.

    #

    # @param element What element to remove.

    # @exception ValueError If a matching element could not be found.

    # @exception AssertionError If the element is not a valid object.

    def remove(self, element):

        assert iselement(element)

        self._children.remove(element)

    ##

    # Returns all subelements.  The elements are returned in document

    # order.

    #

    # @return A list of subelements.

    # @defreturn list of Element instances

    def getchildren(self):

        return self._children

    ##

    # Finds the first matching subelement, by tag name or path.

    #

    # @param path What element to look for.

    # @return The first matching element, or None if no element was found.

    # @defreturn Element or None

    def find(self, path):

        return ElementPath.find(self, path)

    ##

    # 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.

    # @return The text content of the first matching element, or the

    #     default value no element was found.  Note that if the element

    #     has is found, but has no text content, this method returns an

    #     empty string.

    # @defreturn string

    def findtext(self, path, default=None):

        return ElementPath.findtext(self, path, default)

    ##

    # Finds all matching subelements, by tag name or path.

    #

    # @param path What element to look for.

    # @return A list or iterator containing all matching elements,

    #    in document order.

    # @defreturn list of Element instances

    def findall(self, path):

        return ElementPath.findall(self, path)

    ##

    # Resets an element.  This function removes all subelements, clears

    # all attributes, and sets the text and tail attributes to None.

    def clear(self):

        self.attrib.clear()

        self._children = []

        self.text = self.tail = None

    ##

    # Gets an element attribute.

    #

    # @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.

    #

    # @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).

    #

    # @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.

    #

    # @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, the result

    # is undefined.

    #

    # @param tag What tags to look for (default is to return all elements).

    # @return A list or iterator containing all the matching elements.

    # @defreturn list or iterator

    def getiterator(self, tag=None):

        nodes = []

        if tag == "*":

            tag = None

        if tag is None or self.tag == tag:

            nodes.append(self)

        for node in self._children:

            nodes.extend(node.getiterator(tag))

        return nodes

# compatibility

_Element = _ElementInterface

##

# Element factory.  This function returns an object implementing the

# standard Element interface.  The exact class or type of that object

# is implementation dependent, but it will always be compatible with

# the {@link #_ElementInterface} class in this module.

# <p>

# The element name, attribute names, and attribute values can be

# either 8-bit ASCII strings or Unicode strings.

#

# @param tag The element name.

# @param attrib An optional dictionary, containing element attributes.

# @param **extra Additional attributes, given as keyword arguments.

# @return An element instance.

# @defreturn Element

def Element(tag, attrib={}, **extra):

    attrib = attrib.copy()

    attrib.update(extra)

    return _ElementInterface(tag, attrib)

##

# 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.

# <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.

#

# @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:

    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 name.  If given, the

#     tree is initialized with the contents of this XML file.

class ElementTree:

    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.

    # @param parser An optional parser instance.  If not given, the

    #     standard {@link XMLTreeBuilder} parser is used.

    # @return The document root element.

    # @defreturn Element

    def parse(self, source, parser=None):

        if parser:

            tree = default_parser_api.parse(source, parser)

        else:

            tree = parser_api.parse(source)

        self._root = tree

        return tree

    ##

    # 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 getiterator(self, tag=None):

        assert self._root is not None

        return self._root.getiterator(tag)

    ##

    # Finds the first toplevel element with given tag.

    # Same as getroot().find(path).

    #

    # @param path What element to look for.

    # @return The first matching element, or None if no element was found.

    # @defreturn Element or None

    def find(self, path):

        assert self._root is not None

        if path[:1] == "/":

            path = "." + path

        return self._root.find(path)

    ##

    # Finds the element text for the first toplevel element with given

    # tag.  Same as getroot().findtext(path).

    #

    # @param path What toplevel element to look for.

    # @param default What to return if the element was not found.

    # @return The text content of the first matching element, or the

    #     default value no element was found.  Note that if the element

    #     has is found, but has no text content, this method returns an

    #     empty string.

    # @defreturn string

    def findtext(self, path, default=None):

        assert self._root is not None

        if path[:1] == "/":

            path = "." + path

        return self._root.findtext(path, default)

    ##

    # Finds all toplevel elements with the given tag.

    # Same as getroot().findall(path).

    #

    # @param path What element to look for.

    # @return A list or iterator containing all matching elements,

    #    in document order.

    # @defreturn list of Element instances

    def findall(self, path):

        assert self._root is not None

        if path[:1] == "/":

            path = "." + path

        return self._root.findall(path)

    ##

    # Writes the element tree to a file, as XML.

    #

    # @param file A file name, or a file object opened for writing.

    # @param encoding Optional output encoding (default is US-ASCII).

    def write(self, file, encoding="us-ascii"):

        assert self._root is not None

        if not hasattr(file, "write"):

            file = open(file, "wb")

        if not encoding:

            encoding = "us-ascii"

        elif encoding != "utf-8" and encoding != "us-ascii":

            file.write("<?xml version='1.0' encoding='%s'?>\n" % encoding)

        self._write(file, self._root, encoding, {})

    def _write(self, file, node, encoding, namespaces):

        # write XML to file

        tag = node.tag

        if tag is Comment:

            file.write("<!-- %s -->" % _escape_cdata(node.text, encoding))

        elif tag is ProcessingInstruction:

            file.write("<?%s?>" % _escape_cdata(node.text, encoding))

        else:

            items = node.items()

            xmlns_items = [] # new namespaces in this scope

            try:

                if isinstance(tag, QName) or tag[:1] == "{":

                    tag, xmlns = fixtag(tag, namespaces)

                    if xmlns: xmlns_items.append(xmlns)

            except TypeError:

                _raise_serialization_error(tag)

            file.write("<" + _encode(tag, encoding))

            if items or xmlns_items:

                items.sort() # lexical order

                for k, v in items:

                    try:

                        if isinstance(k, QName) or k[:1] == "{":

                            k, xmlns = fixtag(k, namespaces)

                            if xmlns: xmlns_items.append(xmlns)

                    except TypeError:

                        _raise_serialization_error(k)

                    try:

                        if isinstance(v, QName):

                            v, xmlns = fixtag(v, namespaces)

                            if xmlns: xmlns_items.append(xmlns)

                    except TypeError:

                        _raise_serialization_error(v)

                    file.write(" %s=\"%s\"" % (_encode(k, encoding),

                                               _escape_attrib(v, encoding)))

                for k, v in xmlns_items:

                    file.write(" %s=\"%s\"" % (_encode(k, encoding),

                                               _escape_attrib(v, encoding)))

            if node.text or len(node):

                file.write(">")

                if node.text:

                    file.write(_escape_cdata(node.text, encoding))

                for n in node:

                    self._write(file, n, encoding, namespaces)

                file.write("</" + _encode(tag, encoding) + ">")

            else:

                file.write(" />")

            for k, v in xmlns_items:

                del namespaces[v]

        if node.tail:

            file.write(_escape_cdata(node.tail, encoding))

# --------------------------------------------------------------------

# helpers

##

# 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, _ElementInterface) or hasattr(element, "tag")

##

# 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")

def _encode(s, encoding):

    try:

        return s.encode(encoding)

    except AttributeError:

        return s # 1.5.2: assume the string uses the right encoding

if sys.version[:3] == "1.5":

    _escape = re.compile(r"[&<>\"\x80-\xff]+") # 1.5.2

else:

    _escape = re.compile(eval(r'u"[&<>\"\u0080-\uffff]+"'))

_escape_map = {

    "&": "&",

    "<": "&lt;",

    ">": ">",

    '"': """,

}

_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",

}

def _raise_serialization_error(text):

    raise TypeError(

        "cannot serialize %r (type %s)" % (text, type(text).__name__)

        )

def _encode_entity(text, pattern=_escape):

    # map reserved and non-ascii characters to numerical entities

    def escape_entities(m, map=_escape_map):

        out = []

        append = out.append

        for char in m.group():

            text = map.get(char)

            if text is None:

                text = "&#%d;" % ord(char)

            append(text)

        return string.join(out, "")

    try:

        return _encode(pattern.sub(escape_entities, text), "ascii")

    except TypeError:

        _raise_serialization_error(text)

#

# the following functions assume an ascii-compatible encoding

# (or "utf-16")

def _escape_cdata(text, encoding=None, replace=string.replace):

    # escape character data

    try:

        if encoding:

            try:

                text = _encode(text, encoding)

            except UnicodeError:

                return _encode_entity(text)

        if "&" in text:

            text = replace(text, "&", "&")

        if "<" in text:

            text = replace(text, "<", "&lt;")

        if ">" in text:

            text = replace(text, ">", ">")

        return text

    except (TypeError, AttributeError):

        _raise_serialization_error(text)

def _escape_attrib(text, encoding=None, replace=string.replace):

    # escape attribute value

    try:

        if encoding:

            try:

                text = _encode(text, encoding)

            except UnicodeError:

                return _encode_entity(text)

        if "&" in text:

            text = replace(text, "&", "&")

        if "\"" in text:

            text = replace(text, "\"", """)

        if "<" in text:

            text = replace(text, "<", "&lt;")

        if ">" in text:

            text = replace(text, ">", ">")

        if "\n" in text:

            text = replace(text, "\n", "
")

        return text

    except (TypeError, AttributeError):

        _raise_serialization_error(text)

def fixtag(tag, namespaces):

    # given a decorated tag (of the form {uri}tag), return prefixed

    # tag and namespace declaration, if any

    if isinstance(tag, QName):

        tag = tag.text

    namespace_uri, tag = string.split(tag[1:], "}", 1)

    prefix = namespaces.get(namespace_uri)

    if prefix is None:

        prefix = _namespace_map.get(namespace_uri)

        if prefix is None:

            prefix = "ns%d" % len(namespaces)

        namespaces[namespace_uri] = prefix

        if prefix == "xml":

            xmlns = None

        else:

            xmlns = ("xmlns:%s" % prefix, namespace_uri)

    else:

        xmlns = None

    return "%s:%s" % (prefix, tag), xmlns

##

# 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 XMLTreeBuilder} parser is used.

# @return An ElementTree instance

def parse(source, parser=None):

    if parser:

        tree = default_parser_api.parse(source, parser)

    else:

        tree = parser_api.parse(source)

    return ElementTree(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.

# @return A (event, elem) iterator.

def iterparse(source, events=None):

    return parser_api.iterparse(source, events)

class _iterparse:

    def __init__(self, source, events):

        if not hasattr(source, "read"):

            source = open(source, "rb")

        self._file = source

        self._events = []

        self._index = 0

        self.root = self._root = None

        self._parser = XMLTreeBuilder()

        # 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 = _encode(uri, "ascii")

                    except UnicodeError:

                        pass

                    append((event, (prefix or "", uri)))

                parser.StartNamespaceDeclHandler = handler

            elif event == "end-ns":

                def handler(prefix, event=event, append=append):

                    append((event, None))

                parser.EndNamespaceDeclHandler = handler

    def next(self):

        while 1:

            try:

                item = self._events[self._index]

            except IndexError:

                if self._parser is None:

                    self.root = self._root

                    try:

                        raise StopIteration

                    except NameError:

                        raise IndexError

                # load event buffer

                del self._events[:]

                self._index = 0

                data = self._file.read(16384)

                if data:

                    self._parser.feed(data)

                else:

                    self._root = self._parser.close()

                    self._parser = None

            else:

                self._index = self._index + 1

                return item

    try:

        iter

        def __iter__(self):

            return self

    except NameError:

        def __getitem__(self, index):

            return self.next()

##

# 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.

# @return An Element instance.

# @defreturn Element

def XML(text):

    api = parser_api or default_parser_api

    return api.fromstring(text)

##

# 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.

# @return A tuple containing an Element instance and a dictionary.

# @defreturn (Element, dictionary)

def XMLID(text):

    api = parser_api or default_parser_api

    tree = api.fromstring(text)

    ids = {}

    for elem in tree.getiterator():

        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

##

# Generates a string representation of an XML element, including all

# subelements.

#

# @param element An Element instance.

# @return An encoded string containing the XML data.

# @defreturn string

def tostring(element, encoding=None):

    class dummy:

        pass

    data = []

    file = dummy()

    file.write = data.append

    ElementTree(element).write(file, encoding)

    return string.join(data, "")

##

# 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:

    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 = _ElementInterface

        self._factory = element_factory

    ##

    # Flushes the parser buffers, and returns the toplevel documen

    # element.

    #

    # @return An Element instance.

    # @defreturn Element

    def close(self):

        assert len(self._elem) == 0, "missing end tags"

        assert self._last != None, "missing toplevel element"

        return self._last

    def _flush(self):

        if self._data:

            if self._last is not None:

                text = string.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.

# @see #ElementTree

# @see #TreeBuilder

class XMLTreeBuilder:

    def __init__(self, html=0, target=None):

        try:

            from xml.parsers import expat

        except ImportError:

            raise ImportError(

                "No module named expat; use SimpleXMLTreeBuilder instead"

                )

        self._parser = parser = expat.ParserCreate(None, "}")

        if target is None:

            target = TreeBuilder()

        self._target = target

        self._names = {} # name memo cache

        # callbacks

        parser.DefaultHandlerExpand = self._default

        parser.StartElementHandler = self._start

        parser.EndElementHandler = self._end

        parser.CharacterDataHandler = self._data

        # 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

        encoding = None

        if not parser.returns_unicode:

            encoding = "utf-8"

        # target.xml(encoding, None)

        self._doctype = None

        self.entity = {}

    def _fixtext(self, text):

        # convert text string to ascii, if possible

        try:

            return _encode(text, "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

        tag = fixname(tag)

        attrib = {}

        for key, value in attrib_in.items():

            attrib[fixname(key)] = self._fixtext(value)

        return self._target.start(tag, attrib)

    def _start_list(self, tag, attrib_in):

        fixname = self._fixname

        tag = fixname(tag)

        attrib = {}

        if attrib_in:

            for i in range(0, len(attrib_in), 2):

                attrib[fixname(attrib_in[i])] = self._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 _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

                raise expat.error(

                    "undefined entity %s: line %d, column %d" %

                    (text, self._parser.ErrorLineNumber,

                    self._parser.ErrorColumnNumber)

                    )

        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 = string.strip(text)

            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]

                self.doctype(name, pubid, system[1:-1])

                self._doctype = None

    ##

    # Handles a doctype declaration.

    #

    # @param name Doctype name.

    # @param pubid Public identifier.

    # @param system System identifier.

    def doctype(self, name, pubid, system):

        pass

    ##

    # Feeds data to the parser.

    #

    # @param data Encoded data.

    def feed(self, data):

        self._parser.Parse(data, 0)

    ##

    # Finishes feeding data to the parser.

    #

    # @return An element structure.

    # @defreturn Element

    def close(self):

        self._parser.Parse("", 1) # end of data

        tree = self._target.close()

        del self._target, self._parser # get rid of circular references

        return tree

# --------------------------------------------------------------------

# load platform specific extensions

if sys.platform == "cli":

    try:

        import ElementIron

    except ImportError:

        pass # fall back on optional pyexpat emulation

    else:

        parser_api = ElementIron.ParserAPI(TreeBuilder)

elif sys.platform.startswith("java"):

    try:

        import ElementJava

    except ImportError:

        pass

    else:

        parser_api = ElementJava.ParserAPI(TreeBuilder)

    """Generic retrieving wrapper. Eg. dispatch('clear-arp-table') or dispatch element  

    like :

    xsd_fetch = new_ele('get-xnm-information')

    sub_ele(xsd_fetch, 'type').text="xml-schema"

    sub_ele(xsd_fetch, 'namespace').text="junos-configuration

    dispatch(xsd_fetch)    

    to fetch entire xsd sxhema file from Juniper

    """

        return self._request(node)

# in case problems occur include the ElementTree file from the parent dir

# import ElementTree as ET

sub_ele = lambda parent, tag, attrs={}, **extra: ET.SubElement(parent, qualify(tag), attrs, **extra)

      version='0.3.1',