Code for better cloning of ElementTree (XML) objects in Python

ElementTree cloning factory

import xml.etree.cElementTree as ET

"""
ripped off from:
http://effbot.python-hosting.com/file/stuff/sandbox/elementlib/clone.py

apparently this is faster than using copy.deepcopy on an ElementTree
"""

##
# Turns an element tree into a cloning factory.  The callable object
# returned by this function returns copies of the original tree.
#
# @param elem An element tree.
# @return A callable factory object.

def make_factory(elem):
    def generate_elem(append, elem, level):
        var = "e" + str(level)
        arg = repr(elem.tag)
        if elem.attrib:
            arg += ", **%r" % elem.attrib
        if level == 1:
            append(" e1 = Element(%s)" % arg)
        else:
            append(" %s = SubElement(e%d, %s)" % (var, level-1, arg))
        if elem.text:
            append(" %s.text = %r" % (var, elem.text))
        if elem.tail:
            append(" %s.tail = %r" % (var, elem.tail))
        for e in elem:
            generate_elem(append, e, level+1)
    # generate code for a function that creates a tree
    output = ["def element_factory():"]
    generate_elem(output.append, elem, 1)
    output.append(" return e1")
    # setup global function namespace
    namespace = {"Element": ET.Element, "SubElement": ET.SubElement}
    # create function object
    exec "\n".join(output) in namespace
    return namespace["element_factory"]

gistfile1.py

import xml.etree.cElementTree as ET

"""
ripped off from:
http://effbot.python-hosting.com/file/stuff/sandbox/elementlib/clone.py

apparently this is faster than using copy.deepcopy on an ElementTree
"""

##
# Turns an element tree into a cloning factory.  The callable object
# returned by this function returns copies of the original tree.
#
# @param elem An element tree.
# @return A callable factory object.

def make_factory(elem):
    def generate_elem(append, elem, level):
        var = "e" + str(level)
        arg = repr(elem.tag)
        if elem.attrib:
            arg += ", **%r" % elem.attrib
        if level == 1:
            append(" e1 = Element(%s)" % arg)
        else:
            append(" %s = SubElement(e%d, %s)" % (var, level-1, arg))
        if elem.text:
            append(" %s.text = %r" % (var, elem.text))
        if elem.tail:
            append(" %s.tail = %r" % (var, elem.tail))
        for e in elem:
            generate_elem(append, e, level+1)
    # generate code for a function that creates a tree
    output = ["def element_factory():"]
    generate_elem(output.append, elem, 1)
    output.append(" return e1")
    # setup global function namespace
    namespace = {"Element": ET.Element, "SubElement": ET.SubElement}
    # create function object
    exec "\n".join(output) in namespace
    return namespace["element_factory"]