2018-06-27 9:36 GMT+02:00 Michael Selik <m...@selik.org>: > > > On Tue, Jun 26, 2018, 11:43 PM Jacco van Dorp <j.van.d...@deonet.nl> wrote: >> >> 2018-06-26 17:34 GMT+02:00 Franklin? Lee <leewangzhong+pyt...@gmail.com>: >> > Caller detects: The caller checks length before calling the dunder. If >> > there >> > is no dunder, it doesn't check. Are there real-world cases where length >> > is >> > not defined on an iterable collection? >> >> Generators dont have a __len__ method. And they might have min/max >> that can be calculated without iterating over the entire thing. The >> builtin range() is an example. (but also an exception, since it does >> have a __len__ attribute. This is specifically part of range and not >> generators in general, though.). >> >> However, range() is an example where the dunders could be valuable - >> max(range(1e7)) already takes noticable time here, while it's rather >> easy to figure it out from start stop and step, just like len now does >> for it. > > > Have you ever written ``max(range(x))`` in production code?
Have you ever written len(range(x)) in production code ? _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
