How to test if object is sequence, or iterable?

[Marc 'BlackJack' Rintsch]

In <44c26ec2$0$21607$636a55ce at news.free.fr>, Bruno Desthuilliers wrote:

> Tim N. van der Leeuw a écrit :
>> Hi,
>> 
>> I'd like to know if there's a way to check if an object is a sequence,
>> or an iterable. Something like issequence() or isiterable().
>> 
>> Does something like that exist? (Something which, in case of iterable,
>> doesn't consume the first element of the iterable)
> 
> isiterable = lambda obj: isinstance(obj, basestring) \
>                           or getattr(obj, '__iter__', False)
> 
> 
> Should cover most cases.

What about objects that just implement an apropriate `__getitem__()`
method?

Ciao,
	Marc 'BlackJack' Rintsch