On 5 Jan 2006 15:48:26 GMT, Antoon Pardon <[EMAIL PROTECTED]> wrote:
>On 2006-01-04, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
>><[EMAIL PROTECTED]> wrote:
>>> But here is my real question...
>>> Why isn't something like this in itertools, or why shouldn't
>>> it go into itertools?
>>
>>
>> 4) If a need does arise, it can be met by __builtins__.map() or by
>> writing: chain(iterable, repeat(None)).
>>
>> Yes, if youre a python guru. I don't even understand the
>> code presented in this thread that uses chain/repeat,
>
>And it wouldn't work in this case. chain(iterable, repeat(None))
>changes your iterable into an iterator that first gives you
>all elements in the iterator and when these are exhausted
>will continue giving the repeat parameter. e.g.
>
> chain([3,5,8],repeat("Bye")
>
>Will produce 3, 5 and 8 followed by an endless stream
>of "Bye".
>
>But if you do this with all iterables, and you have to
>because you don't know which one is the smaller, all
>iterators will be infinite and izip will never stop.
But you can fix that (only test is what you see ;-) :
>>> from itertools import repeat, chain, izip
>>> it = iter(lambda z=izip(chain([3,5,8],repeat("Bye")),
>>> chain([11,22],repeat("Bye"))):z.next(), ("Bye","Bye"))
>>> for t in it: print t
...
(3, 11)
(5, 22)
(8, 'Bye')
(Feel free to generalize ;-)
Regards,
Bengt Richter
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