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Re: Why does argparse return None instead of [] if an append action isn't used?

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On Mon, Jan 26, 2015 at 8:50 AM, Adam Funk <a24061@ducksburg.com> wrote:
> On 2015-01-26, Peter Otten wrote:
>
>> Adam Funk wrote:
>>
>>> On 2015-01-09, Ned Batchelder wrote:
>>>>      for b in options.bar or ():
>>>>          do_stuff(b)
>>>
>>> Do you mean "for b in options.bar or []:" ?
>>
>> Doesn't matter; in the context of a for loop any empty iterable would do.
>
> Of course it would.  Doh!

Stylistically, I generally prefer the empty list for this. The empty
tuple might be a little faster since it's a singleton and doesn't need
to be constructed at runtime, but that's clearly a micro-optimization,
and I think the list more accurately conveys the intention of
"something to be iterated over". Although tuples are iterable, I don't
often use them for that purpose.

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Why does argparse return None instead of [] if an append action isn't used? Adam Funk <a24061@ducksburg.com> - 2015-01-09 14:44 +0000
  Re: Why does argparse return None instead of [] if an append action isn't used? Skip Montanaro <skip.montanaro@gmail.com> - 2015-01-09 08:57 -0600
    Re: Why does argparse return None instead of [] if an append action isn't used? Adam Funk <a24061@ducksburg.com> - 2015-01-09 15:25 +0000
  Re: Why does argparse return None instead of [] if an append action isn't used? Ned Batchelder <ned@nedbatchelder.com> - 2015-01-09 10:12 -0500
    Re: Why does argparse return None instead of [] if an append action isn't used? Adam Funk <a24061@ducksburg.com> - 2015-01-26 13:43 +0000
      Re: Why does argparse return None instead of [] if an append action isn't used? Peter Otten <__peter__@web.de> - 2015-01-26 15:04 +0100
        Re: Why does argparse return None instead of [] if an append action isn't used? Adam Funk <a24061@ducksburg.com> - 2015-01-26 15:50 +0000
          Re: Why does argparse return None instead of [] if an append action isn't used? Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-26 09:13 -0700
            Re: Why does argparse return None instead of [] if an append action isn't used? Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2015-01-26 18:29 +0200
              Re: Why does argparse return None instead of [] if an append action isn't used? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-01-26 17:18 +0000
              Re: Why does argparse return None instead of [] if an append action isn't used? Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-26 11:23 -0700
              Re: Why does argparse return None instead of [] if an append action isn't used? Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-26 11:26 -0700
  Re: Why does argparse return None instead of [] if an append action isn't used? Wolfgang Maier <wolfgang.maier@biologie.uni-freiburg.de> - 2015-01-09 16:50 +0100
    Re: Why does argparse return None instead of [] if an append action isn't used? Adam Funk <a24061@ducksburg.com> - 2015-01-26 13:43 +0000

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