def remove_xmlns(xml_string):
        """
        changes the xmlns (XML namespace) so that values are
        replaced with the string representation of their key
        this makes the import process for portable

        >>> xp = XML_parser
        >>> test_xmlns = r'<rss version="2.0" xmlns:excerpt="http://wordpress.org/export/1.2/excerpt/">'
        >>> xp.remove_xmlns(test_xmlns)
        '<rss version="2.0" xmlns:excerpt="excerpt">'
        """
        # splitting xml into sections, pre_chan is preamble before <channel>
        pre_chan, chan, post_chan= xml_string.partition('<channel>')
        # replace xmlns statements on preamble
        pre_chan = re.sub(r'xmlns:(?P<label>\w*)\=\"(?P<val>[^\"]*)\"',
                             r'xmlns:\g<label>="\g<label>"',
                             pre_chan)
        # piece back together
        return pre_chan + chan + post_chan