On Tue, Jun 23, 2020 at 10:10 AM MRAB <python@mrabarnett.plus.com> wrote:
Why are:

     case ._:

not OK?

In this:

     case .BLACK:
     case BLACK:

the first matches the value against 'BLACK' and the second succeeds and
binds the value to 'BLACK'.

Replacing 'BLACK' with '_':

     case ._:
     case _:

I'd expect something similar, except for the binding part.

I think the same could be said for:

     case Color.BLACK:


     case _.BLACK:

The PEP authors discussed this last night and (with a simple majority) we agreed that this restriction isn't all that important, so we're dropping it.

(We're considering other feedback carefully, but most of it require more deliberation.)

--Guido van Rossum (python.org/~guido)