[Python-Dev] argparse ugliness

[Steven Bethard]

On Mon, Mar 8, 2010 at 7:40 AM, Steven Bethard <steven.bethard at gmail.com> wrote:
> 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)

Sorry, that should have been:

  parser.add_argument('--plot', action=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
>



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