[Tutor] Why begin a function name with an underscore

[Richard D. Moores]

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?

Dick Moores