[Python-Dev] PEP 201 - Parallel iteration
Gordon McMillan
gmcm@hypernet.com
Tue, 18 Jul 2000 08:26:02 -0400
Moshe Zadka wrote:
> (assume a = [1, 2, 3])
>
> On Mon, 17 Jul 2000, Gordon McMillan wrote:
>
> > How about a fourth: zip(a) is the same as zip(a, []) ?
>
> Huh???????????????????
>
> > Look at it this way: what should zip(a, pad=None) return?
>
> [(1,), (2,), (3,)], of course
Then why does the PEP say:
>>> zip(a, b, c, d, pad=None)
[(1, 5, 9, 12), (2, 6, 10, 13), (3, 7, 11, None), (4, 8, None, None)]
>>> map(None, a, b, c, d)
[(1, 5, 9, 12), (2, 6, 10, 13), (3, 7, 11, None), (4, 8, None, None)]
If you want no padding, you don't specify a pad arg. pad=None
means "pad with None".
> > Obviously: [(1, None), (2, None), (3, None)]
>
> Why?
To be consistent.
- Gordon