On Wed, 27 Jul 2022 at 21:13, Mathew Elman <[email protected]> wrote:
>
> To answer how this _could_ work, Undefined would be a new NoneType that is
> falsey (just like None) can't be reassigned (just like None) and does
> everything else just like None _except_ that when it is passed as a function
> argument, the argument name is bound to the default if it has one instead.
>
Okay. Everything else just like None. So I can do this?
a = Undefined
b = {1: Undefined}
c = {Undefined: 2}
print(b[1])
a in c # s/be True
c[a] # s/be 2
What would these do? And especially, what would happen if, instead of
vanilla dictionaries, b and c were custom classes?
ChrisA
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