New submission from Marco Sulla <launchpad....@marco.sulla.e4ward.com>:
I noticed that `__contains__()` and `__getitem__()` of subclasses of `dict` are much slower. I asked why on StackOverflow, and an user seemed to find the reason. The problem for him/her is that `dict` implements directly `__contains__()` and `__getitem__()`. Usually, `sq_contains` and `mp_subscript` are wrapped to implement `__contains__()` and `__getitem__()`, but this way `dict` is a little faster, I suppose. The problem is that `update_one_slot()` searches for the wrappers. If it does not find them, it does not inherit the `__contains__()` and `__getitem__()` of the class, but create a `__contains__()` and `__getitem__()` functions that do an MRO search and call the superclass method. This is why `__contains__()` and `__getitem__()` of `dict` subclasses are slower. Is it possible to modify `update_one_slot()` so that, if no wrapper is found, the explicit implementation is inherited? SO answer: https://stackoverflow.com/a/59914459/1763602 ---------- components: C API messages: 362662 nosy: Marco Sulla priority: normal severity: normal status: open title: update_one_slot() does not inherit sq_contains and mp_subscript if they are explictly declared type: performance versions: Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue39754> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
