[Tutor] Why begin a function name with an underscore

[Timo]

Op 28-08-12 10:06, Richard D. Moores schreef:
> On Tue, Aug 28, 2012 at 12:13 AM, Jerry Zhang <jerry.scofield at gmail.com> wrote:
>>
>> 2012/8/28 Richard D. Moores <rdmoores at gmail.com>
>>
>>> On Mon, Aug 27, 2012 at 6:33 PM, Japhy Bartlett <japhy at pearachute.com>
>>> wrote:
>>>
>>>> something like:
>>>>
>>>> def _validate_int(obj):
>>>>      """Raise an exception if obj is not an integer."""
>>>>      m = int(obj + 0)  # May raise TypeError.
>>>>      if obj != m:
>>>>          raise ValueError('expected an integer but got %r' % obj)
>>>>
>>>>
>>>> is a really awkward way to test if something's an integer, and checking
>>>> types in general is usually a sign of larger flaws in laying out useful
>>>> code.
>>> What the best way to test if something's an integer?
>>
>>>>> a = 4
>>>>> isinstance(a, int)
>> True
>>>> isinstance(3., int)
> False
>
> What if I wanted 3., 1234., etc. to be considered ints, as they are by
> _validate_int()  ?

 >>> isinstance(3., (int, float))
True

Because 3. is a float, not int.

Timo

>
> Dick
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> To unsubscribe or change subscription options:
> http://mail.python.org/mailman/listinfo/tutor