Raymond Hettinger <raymond.hettin...@gmail.com> added the comment:
> The usually recommended alternative is to make a new list of > things not deleted. But one can do this in-place by writing > the new list on top of the old by using a explicit second > index to move items just once. I don't think we should send users down this path. Better to stick with high level, easy-to-implement and performant suggestions: """ To edit a list in-place it is often simplest and fastest to replace the entire list: colors[:] = [color for color in colors if websafe(color)] This makes a single pass through the list and efficiently builds a new list. The colors[:] then replaces the entire contents of the original list with the new list """ Besides being easy to get right, this is likely to be *much* faster than tracking two indicies to manipulate the array in-place. Slice operations run at the speed of a C memcpy (plus the ref count changes) and don't involve creating and destroying integer objects for indexing. ---------- nosy: +rhettinger _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue41774> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
