_fromstring

    Convert XML string value to None, boolean, int or float.

def _fromstring(value):
    '''_fromstring

    Convert XML string value to None, boolean, int or float.
    '''

    if not value:
        return None
    std_value = value.strip().lower()
    if std_value == 'true':
        return 'true'
    elif std_value == 'false':
        return 'false'
#     try:
#         return int(std_value)
#     except ValueError:
#         pass
#     try:
#         return float(std_value)
#     except ValueError:
#         pass
    return value