[Python-ideas] Add 'interleave' function to itertools?

[Andrew Barnert]

On Aug 7, 2013, at 13:02, Serhiy Storchaka <storchaka at gmail.com> wrote:

> 07.08.13 22:19, Vito De Tullio написав(ла):
>> MRAB wrote:
>> 
>>> def interleave(*iterables):
>>>      """Return a interleave object whose .__next__() method returns an
>>>      element from each iterable argument in turn.  The .__next__()
>>>      method continues until the shortest iterable in the argument
>>>      sequence is exhausted and then it raises StopIteration.
>>>      """
>>> 
>>>      sources = [iter(iterable) for iterable in iterables]
>>> 
>>>      try:
>>>          while True:
>>>              for iterable in sources:
>>>                  yield next(iterable)
>>>      except StopIteration:
>>>          pass
>> 
>> isn't something like
>> 
>>     def interleave(*iterables):
>>         for zipped_iterables in zip(*iterables):
>>            yield from zipped_iterables
>> 
>> sufficient?
> 
> chain.from_iterable(zip(*iterables))

Yet another reason why chain.from_iterable should be more discoverable. The operation is obviously just flattening/chaining a zip, and the only reason that isn't the obvious code for many people is that they don't know how to flatten.