code: def get_xml_attr(source, name, path=None):
    
    if path is None:
      return source.attrib[name]
    else:
      return get_xml_attr(get_xml_child(source, path), name)
docs: Get the XML attribute with name from source. If path is not Mone, it will instead get the
    XML attribute with name from the child indicated by path.