On 3/21/07, Tobias Ivarsson <thobes@gmail.com> wrote:
Quite often I find myself wanting to write an infinite for-loop, or rather a loop with a counter, that terminates on some inner condition. Recently I even wanted to do this together with the generator comprehension syntax, I don't remember exactly what I wanted to do, but it was something like: zip( some_list_of_unknown_length, ('a' for x in infinit_generator) ) I admit that my example is silly, but it still serves as an example of what I wanted to do.
itertools.count() (http://docs.python.org/lib/itertools-functions.html) handles just this. Wrapping it in a genexp can take care of the second example:
for i in range(...): ... print i ... if i == 4: break
for i in itertools.count(): ....
for i in range(10,...,10): ... print i ... if i == 40: break
for i in (i * 10 for i in itertools.count(1)): .... Collin Winter