On Mon, Oct 15, 2018 at 6:00 AM Albert-Jan Roskam <sjeik_ap...@hotmail.com> wrote: > > In Python 3.6 (Windows) I often see a forward slash in a function signature, > see below. > What does it mean? I vaguely remember reading something about new > possbilities in > python 3, something like "def foo(x, *, y)". Perhaps it's related to that? > > >>> help({}.fromkeys) > Help on built-in function fromkeys: > > fromkeys(iterable, value=None, /) method of builtins.type instance > Returns a new dict with keys from iterable and values equal to value.
This syntax is for position-only function parameters. It's used by Argument Clinic [1], a preprocessor used internally to develop CPython. Position-only parameters have also been proposed for the language grammar, first in PEP 457 and again in PEP 570 [2]. [1]: https://docs.python.org/3/howto/clinic.html#converting-your-first-function [2]: https://www.python.org/dev/peps/pep-0570 _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor