On Thu, 16 Mar 2023 at 01:26, David Raymond <david.raym...@tomtom.com> wrote: > I'm not quite sure why the built-in sum functions are slower than the for > loop, > or why they're slower with the generator expression than with the list > comprehension.
For small-to-medium data sizes, genexps are slower than list comps, but use less memory. (At some point, using less memory translates directly into faster runtime.) But even the sum-with-genexp version is notably faster than reduce. Is 'weights' a dictionary? You're iterating over it, then subscripting every time. If it is, try simply taking the sum of weights.values(), as this should be significantly faster. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
