On Sat, Jan 4, 2014 at 2:51 AM, Roy Smith <r...@panix.com> wrote: > In article <mailman.4853.1388763434.18130.python-l...@python.org>, > Chris Angelico <ros...@gmail.com> wrote: > >> Alternatively, if you expect to fill in most of the elements, it's >> possible you'd be happier working with a subclass of list that >> auto-expands by filling in the spare space with a singleton meaning >> "no element here". > > And, if you know ahead of time the maximum number of elements you will > ever have: > > x = [None] * max_count > > will preallocate them all with a minimum of fuss.
Yes, as I use in the trivial example in the subsequent post. But as a general solution this is usually insufficient. (Whether or not None is valid as a sentinel is, of course, quite orthogonal to the discussion. I avoided assuming that it was, the OP's now shown that it does seem to be.) ChrisA -- https://mail.python.org/mailman/listinfo/python-list
