On Mon, Jan 8, 2018 at 4:21 PM, Ethan Furman <et...@stoneleaf.us> wrote: > On 01/07/2018 04:57 PM, Chris Angelico wrote: >> >> On Mon, Jan 8, 2018 at 11:35 AM, Ben Finney wrote: >>> >>> Chris Angelico writes: > > >>>> Let's put it this way. Suppose that __eq__ existed and __ne__ didn't, >>>> just like with __contains__. Go ahead: sell the notion of __ne__. >>>> Pitch it, show why we absolutely need to allow this. >>> >>> >>> I think “reject unless absolutely needed” is an unreasonably high bar, >>> which would disqualify most Python language features. So I don't know >>> why you expect this to be so especially strongly argued. >> >> >> True, I exaggerated a bit. But do you think that, had __ne__ not >> existed for years, its addition could be justified? > > > Considering we just recently added a matrix-multiplication operator, yes. >
That has approximately zero consequences on class authors. If you were unaware of __matmul__, it wouldn't have the chance to randomly break your __mul__ semantics. And even with that excellent backward compatibility, it STILL took many years to get accepted. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
