[Python-Dev] itertools.chain should take an iterable ?

[Paolino]

Jack Diederich wrote:
> On Thu, Sep 01, 2005 at 07:58:40PM +0200, Paolino wrote:
> 
>>Working on a tree library I've found myself writing 
>>itertools.chain(*[child.method() for child in self]).
>>Well this happened after I tried instinctively 
>>itertools.chain(child.method() for child in self).
>>
>>Is there a reason for this signature ?
> 
> 
> This is more suited to comp.lang.python
> 
Why ? I'm not asking for help ,I'm asking why itertools library is 
implemented like that and if it is possible to clean it.

> Consider the below examples (and remember that strings are iterable)
> 
> 
>>>>import itertools as it
>>>>list(it.chain('ABC', 'XYZ'))
> 
> ['A', 'B', 'C', 'X', 'Y', 'Z']
> 
>>>>list(it.chain(['ABC', 'XYZ']))
> 
> ['ABC', 'XYZ']
> 
>>>>list(it.chain(['ABC'], ['XYZ']))
> 
> ['ABC', 'XYZ']
> 
What if I want to chain an infinite list of iterables?
Shouldn't itertools.chain be built to  handle that?
I don't think it is a problem to accept only the second case you paste 
and produce TypeError on the others.

Hope this explains and  to get other reasons.

Regards
Paolino

> 
> Hope that helps,
> 
> -jackdied
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