import sys
from lxml import etree
def odml_to_html(odml_filename, html_filename=None):
    """
    Load an odML xml file containing a full and valid stylesheet tag and
    use the stylesheet information to transform the odml document to html.
    :param odml_filename: odML XML file containing a full custom XSLT style.
    """
    dom = etree.parse(odml_filename)
    style = dom.xpath("/odML")
    if not style:
        print("Could not find odML tag")
        return
    getstyle = style[0].findall("{http://www.w3.org/1999/XSL/Transform}stylesheet")
    if not getstyle:
        print("Could not find custom stylesheet tag")
        return
    transform = etree.XSLT(getstyle[0])
    newdom = transform(dom)
    html = etree.tostring(newdom, pretty_print=True).decode()
    if html_filename:
        with open(html_filename, "w") as fip:
            fip.write(html)
    else:
        return html

if __name__=='__main__':
    import sys
    odml_to_html(sys.argv[1:])