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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 10:18 AM, Mark Lawrence <breamoreboy@yahoo.co.uk> wrote:
> IIRC, and probably from this list, creating tuples is way faster than
> creating lists, but accessing items is slower.  Can anybody confirm this for
> us?

The first seems to be true as long as the tuples are small.

$ python3 -m timeit 't = (1000, 2000, 3000)'
100000000 loops, best of 3: 0.0147 usec per loop
$ python3 -m timeit 't = [1000, 2000, 3000]'
10000000 loops, best of 3: 0.0678 usec per loop
$ python3 -m timeit 't = tuple(range(10000))'
10000 loops, best of 3: 183 usec per loop
$ python3 -m timeit 't = list(range(10000))'
10000 loops, best of 3: 174 usec per loop
$ python3 -m timeit 't = tuple(range(10000000))'
10 loops, best of 3: 323 msec per loop
$ python3 -m timeit 't = list(range(10000000))'
10 loops, best of 3: 306 msec per loop

This is probably a result of the use of freelists to avoid
reallocating the tuple objects, though. I don't see any substantial
difference in access time:

$ python3 -m timeit -s 't = tuple(range(10000))' 't[5000]'
10000000 loops, best of 3: 0.0316 usec per loop
$ python3 -m timeit -s 't = list(range(10000))' 't[5000]'
10000000 loops, best of 3: 0.0318 usec per loop
$ python3 -m timeit -s 't = tuple(range(10000))' 'for x in t: pass'
10000 loops, best of 3: 112 usec per loop
$ python3 -m timeit -s 't = list(range(10000))' 'for x in t: pass'
10000 loops, best of 3: 113 usec per loop

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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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