Re: [Python-ideas] Null coalescing operator

On Thu, Nov 03, 2016 at 12:35:07PM -0700, Chris Barker wrote:

On Thu, Nov 3, 2016 at 12:00 PM, MRAB wrote:

...

self.an_arg = the_default if an_arg is None else an_arg

...

No, ?? is a bit like 'or', except that only None is falsey, so it would be:

self.an_arg = an_arg ?? the_default

thanks! and actually, that reads much better to me.

That suggests a possible different colour for this operator: `?or`. (Apologies if that's already been suggested and rejected earlier.) The None-aware "safe navigation" operators ?. and ?[] will be used where Python already uses punctuation: spam.eggs # ordinary attribute lookup spam?.eggs # None-aware attribute lookup spam[eggs] # ordinary item lookup spam?[eggs] # None-aware item lookup which is simple enough to remember: just prefix your usual operator with a question mark to make it None-aware. But one of the disadvantages of ?? as an operator is that it replaces a keyword with completely unrelated punctuation: spam or default # default only if spam is any Falsey value spam ?? default # default only if spam is None Compared to: spam ?or default gives us the same rule: prefix the `or` operator with ? to make it None- aware. -- Steve