[Python-ideas] Changing str(someclass) to return only the class name

[Éric Araujo]

Hi,

Le 22/10/2011 22:18, Steven D'Aprano a écrit :
> I'm just going to repeat what I've said before: explicit is better than 
> implicit. If you want the name of an object (be it a class, a module, a 
> function, or something else), you should explicitly ask for the name, 
> and not rely on its str().
> 
> [...]
> 
> But for the sake of the argument, I'll grant you that we're free to 
> change str(cls) to return the class name, as requested by the OP, or the 
> fully qualified module.class dotted name as suggested by you. So let's 
> suppose that, after a long and bitter debate over which colour to paint 
> this bikeshed, you win the debate.

Hm.  Sometimes we want the class name, sometimes module.class, so even
with the change we won’t always be able to use str(cls).

> But this doesn't help you at all, because you can't rely on it. It seems 
> to me that the exact format of str(cls) is an implementation detail. You 
> can't rely on other Pythons to do the same thing, nor can you expect a 
> guarantee that str(cls) won't change again in the future. So if you care 
> about the exact string that gets generated, you still have to explicitly 
> use cls.__name__ just as you do now.

This is a very good point.

The output of repr and str is not (TTBOMK) exactly defined or
guaranteed; nonetheless, I expect that many people (including me) rely
on some conversions (like the fact that repr('somestr') includes
quotes).  So we can change str(cls) and say that *now* it has defined
output, or leave it alone to avoid breaking code that does depend on the
output, which can be seen as a wrong thing or a pragmatic thing (“I need
it and it works”).

Regards