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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove_namespace(doc, namespace):
 """ Takes in a ElementTree object and namespace value. The length of that namespace value is removed from all Element nodes within the document. This effectively removes the namespace from that document. :param doc: lxml.etree :param namespace: Namespace that needs to be removed. :return: Returns the source document with namespaces removed. """

    # http://homework.nwsnet.de/products/45be_remove-namespace-in-an-xml-document-using-elementtree
    #
    # Permission is hereby granted, free of charge, to any person obtaining
    # a copy of this software and associated documentation files (the
    # "Software"), to deal in the Software without restriction, including
    # without limitation the rights to use, copy, modify, merge, publish,
    # distribute, sublicense, and/or sell copies of the Software, and to
    # permit persons to whom the Software is furnished to do so, subject to
    # the following conditions:
    #
    # The above copyright notice and this permission notice shall be
    # included in all copies or substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
    # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
    # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
    # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
    ns = '{{{}}}'.format(namespace)
    nsl = len(ns)
    # print 'DEBUG: removing',ns
    for elem in doc.getiterator():
        if elem.tag.startswith(ns):
            elem.tag = elem.tag[nsl:]
    return doc