[Python-3000] PEP 3100 Comments

[Greg Ewing]

Talin wrote:

> A common Python idiom is to take different actions based on the capabilities
> of an object rather than its type.

I have no objection to that when the capability can be
tested for easily and efficiently and without danger of
causing undesirable side effects. But callability is
not such a capability, therefore I think it's a bad
idea to design an API which relies on being able to
test for it.

--
Greg