Working with method-wrapper objects

[Dr. Peer Griebel]

Peer Dr. Griebel wrote:
> I think I was a little bit unspecific in my last mail.
> 
> I would like to see some description about method-wrapper and
> wrapper_descriptor objects.  I dont' understand the following behaviour:
> 
> 
>>>>type([].__str__)
> 
> <type 'method-wrapper'>
> 
>>>>type(object.__str__)
> 
> <type 'wrapper_descriptor'>
> 
>>>>type(object().__str__)
> 
> <type 'method-wrapper'>
> 
>>>>import inspect
>>>>inspect.isroutine([].__str__)
> 
> False
> 
>>>>inspect.isroutine(object.__str__)
> 
> True
> 
>>>>inspect.isroutine(object().__str__)
> 
> False
> 
> Why has [].__str__ a different type than object.__str__?
> Why is object.__str__ a routine while object().__str__ not?
> 
> And one again my question: Can I extract some more information about a
> methed-wrapper object. E.g. can I somehow determine the arg spec?
> 
> Thanks
>   Peer

Isn't there anybody who has something to say about the issue?

I think it's not only a problem with inspect. It is aproblem about old 
style classes vs. new style classes. It seems that the support for new 
style classes is not complete (yet).

Some more investigation shows that also the module "types" is not 
universally usable. E.g. InstanceType is only usabel for instances of 
old classes. How do I test for instances of new classes?

Thanks
   Peer