Hi, I'm also looking at listobject.c also... if we want list.clear() to behave exactly like del list[], we may be able to just call list_ass_slice on the list. Similarly for list.copy which should behave like a=l[:]

Note that when executed to do 'del lst[:]' (i.e. with argument v set to 0 and ilow/ihigh to the maximal range of the list), list_ass_slice will just call list_clear anyway, which is a cue that this indeed is the right way to do it, despite the strange comment I mentioned in my message above.