Raymond Hettinger <raymond.hettin...@gmail.com> added the comment: > If space is not an issue, the list comprehension may be fastest.
I think there is still a misunderstanding here. The generator variant does not save space. It uses slightly *more* space than the list variant. The list_ass_slice()¹ function runs PySequence_Fast² on its input. If the input is already a list or tuple, it is returned immediately. If not, the iterator is run to exhaustion and a new list is built. Either way, when the actual update occurs, the source will be a list or tuple. ¹ https://github.com/rhettinger/cpython/blob/master/Objects/listobject.c#L597 ² https://github.com/rhettinger/cpython/blob/master/Objects/abstract.c#L2014 ---------- _______________________________________ 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