How to use the dateparser.utils.strptime.strptime function in dateparser

def when_date_string_is_parsed(self, date_string, fmt):
        try:
            self.result = strptime(date_string, fmt)
        except ValueError as e:
            self.result = e

def _get_date_obj(self, token, directive):
        return strptime(token, directive)

def __call__(self, timestring):
        _timestring = timestring
        for directive in self.time_directives:
            try:
                return strptime(timestring.strip(), directive).time()
            except ValueError:
                pass
        else:
            raise ValueError('%s does not seem to be a valid time string' % _timestring)