@classmethod
def strptime(cls, date_string, format_):
    """Python 2.4 compatible"""
    import datetime
    if hasattr(datetime.datetime, 'strptime'):
        strptime_ = datetime.datetime.strptime
    else:
        import time
        strptime_ = lambda date_string, format_: datetime.datetime(*time.
            strptime(date_string, format_)[0:6])
    return strptime_(date_string, format_)
