Peter Otten wrote: > Here is another implementation that cuts maximum memory down from 100 to > 50%. > > from itertools import islice > def swap(items): > items[::2], items[1::2] = islice(items, 1, None, 2), items[::2] > return items
Unfortunately, the following >>> a = [1, 2, 3] >>> a[::2] = iter([10, 20, 30]) Traceback (most recent call last): File "<stdin>", line 1, in ? ValueError: attempt to assign sequence of size 3 to extended slice of size 2 >>> a [1, 2, 3] does not support my bold claim :-( Since the list is not changed there must be an intermediate copy. Peter -- http://mail.python.org/mailman/listinfo/python-list
