[Python-Dev] argparse ugliness

[Steven Bethard]

On Sun, Mar 7, 2010 at 11:49 AM, Guido van Rossum <guido at python.org> wrote:
> On Sun, Mar 7, 2010 at 4:29 AM, Neal Becker <ndbecker2 at gmail.com> wrote:
>> Brian Curtin wrote:
>>
>>> On Fri, Mar 5, 2010 at 12:51, Neal Becker <ndbecker2 at gmail.com> wrote:
>>>
>>>> I generally enjoy argparse, but one thing I find rather
>>>> ugly and unpythonic.
>>>>
>>>>    parser.add_argument ('--plot', action='store_true')
>>>>
>>>> Specifying the argument 'action' as a string is IMO ugly.
>>>>
>>>
>>> What else would you propose?
>>> FWIW, this is the same in optparse.
>>
>> I would have thought use the object itself, instead of a string that spells
>> the object's name.
>
> What object? How would you write the example instead then?

In argparse, unlike optparse, actions are actually defined by objects
with a particular API, and the string is just a shorthand for
referring to that. So:

  parser.add_argument ('--plot', action='store_true')

is equivalent to:

  parser.add_argument('--plot', argparse._StoreTrueAction)

Because the names are so long and you'd have to import them, I've left
them as private attributes of the module, but if there's really
demand, we could rename them to argparse.StoreTrueAction, etc.

Steve
-- 
Where did you get that preposterous hypothesis?
Did Steve tell you that?
        --- The Hiphopopotamus