On Mon, Mar 18, 2019 at 7:04 AM Rhodri James <rho...@kynesim.co.uk> wrote:
> On 18/03/2019 12:19, Richard Damon wrote: > > On 3/18/19 7:27 AM, Greg Ewing wrote: > >> Juancarlo Añez wrote: > >> > >>> if settings[MY_KEY] is True: > >>> ... > >> > >> If I saw code like this, it would take a really good argument to > >> convince me that it shouldn't be just > >> > >> if settings[MY_KEY]: > >> ... > >> > > That means something VERY different. The first asks if the item is > > specifically the True value, while the second just asks if the value is > > Truthy, it wold be satisfied also for values like 1. > > Yes. And the latter is what people almost always mean. > No, it depends heavily on the context. In GUI code, Oleg's example (tri-state checkbox) is a pervasive idiom. There's lots of code that says "if x is True" or "if x is False" or "if x is None" and that's a very clear indicator that you are dealing with these "booleans that can also be 'unset'".
_______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
