In document https://docs.python.org/2/library/argparse.html#argparse.RawDescriptionHelpFormatter

this will fail with NameError: global name 'textwrap' is not defiend

>>> parser = argparse.ArgumentParser(
...     prog='PROG',
...     formatter_class=argparse.RawDescriptionHelpFormatter,
...     description=textwrap.dedent('''\
...         Please do not mess up this text!
...         --------------------------------
...             I have indented it
...             exactly the way
...             I want it
...         '''))