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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _strptime(expr, date_format):
 """ Return datetimes specified by date_format, which supports the same string format as the python standard library. Details of the string format can be found in python string format doc :param expr: :param date_format: date format string (e.g. “%Y-%m-%d”) :type date_format: str :return: """


    return _string_op(expr, Strptime, _date_format=date_format,
                      output_type=types.datetime)