[EMAIL PROTECTED] wrote: > itertools.count docs say: > Does not currently support python long integers. > Note, count() does not check for overflow and will return negative > numbers after exceeding sys.maxint. This behavior may change in the > future. > > But it seems it doesn't support negative numbers too: > > >>> from itertools import count, islice > >>> list(islice(count(), 0, 5)) > [0, 1, 2, 3, 4] > >>> list(islice(count(10), 0, 5)) > [10, 11, 12, 13, 14] > >>> list(islice(count(-3), 0, 5)) > [4294967293L, 4294967294L, 4294967295L, 0, 1] > >>> def count2(n=0): > ... while True: > ... yield n > ... n += 1 > ... > >>> list(islice(count2(-3), 0, 5)) > [-3, -2, -1, 0, 1] > > If this isn't a bug, then maybe docs can tell about this too.
Seems like a regression to me. itertools was documented as taking a sequence of integers, not necessarily positive integers. It worked on Python 2.4. Looking at the source (from 2.5 rc2), it looks like they accidentally used PyInt_FromSize_t rather than PyInt_FromSSize_t in the count iterator. size_t is unsigned, of course, hence the large negative numbers. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
