[Python-Dev] pprint(iterator)

[Aahz]

On Thu, Jan 29, 2009, Michael Foord wrote:
> Aahz wrote:
>> On Tue, Jan 27, 2009, Raymond Hettinger wrote:
>>   
>>> It is becoming the norm in 3.x for functions to return iterators,
>>> generators, or views whereever possible.
>>>
>>> I had a thought that pprint() ought to be taught to print iterators:
>>>
>>>    pprint(enumerate(seq))
>>>    pprint(map(somefunc, somedata))
>>>    pprint(permutations(elements))
>>>    pprint(mydict.items())
>>>     
>>
>> The reason I'm chiming in is that I would welcome a PEP that created a
>> __pprint__ method as an alternative to special-casing.  I think that it
>> would be generically useful for user-created objects, plus once you've
>> added this feature other people can easily do some of the grunt work of
>> extending this through the Python core.  (Actually, unless someone
>> objects, I don't think a PEP is required, but it would be good for the
>> usual reasons that PEPs are written, to provide a central place
>> documenting the addition.)
>   
> Don't we have a pretty-print API - and isn't it spelled __str__ ?

In theory, yes.  In practice, we wouldn't be having this discussion if
that really worked.  But it probably would make sense to see how far
using __str__ can take us -- AFAICT enumobject.c doesn't define __str__
(although I may be missing something, I don't know Python at the C level
very well).
-- 
Aahz (aahz at pythoncraft.com)           <*>         http://www.pythoncraft.com/

Weinberg's Second Law: If builders built buildings the way programmers wrote 
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