On 18 October 2017 at 20:39, Koos Zevenhoven <k7hoven@gmail.com> wrote:

On Oct 18, 2017 13:29, "Nick Coghlan" <ncoghlan@gmail.com> wrote:

On 18 October 2017 at 19:56, Koos Zevenhoven <k7hoven@gmail.com> wrote:

I'm unable to reproduce the "uninterruptible with Ctrl-C"​ problem with infinite iterators. At least itertools doesn't seem to have it:

>>> import itertools

>>> for i in itertools.count():

...     pass

... 

That's interrupting the for loop, not the iterator. This is the test case you want for the problem Jason raised:

    >>> "a" in itertools.count()

Be prepared to suspend and terminate the affected process, because Ctrl-C isn't going to help :)

I'm writing from my phone now, cause I was dumb enough to try list(count())

Yeah, that's pretty much the worst case example, since the machine starts thrashing memory long before it actually gives up and starts denying the allocation requests :(

 

But should it be fixed in list or in count?

That one can only be fixed in count() - list already checks operator.length_hint(), so implementing itertools.count.__length_hint__() to always raise an exception would be enough to handle the container constructor case.