[Ethan Furman firstname.lastname@example.org]
"case _:" is easy to miss -- I missed it several times reading through the PEP.
As I said, I don't care about "shallow first impressions". I care about how a thing hangs together _after_ climbing its learning curve - which in this case is about a nanometer tall ;-)
You're not seriously going to maintain that you're struggling to grasp the meaning of "case _:" now, right?
Huh. I would consider "case _:" to be the wart, especially since "case default:" or "case anything:" or "case i_dont_care:" all do basically the same thing (although they bind to the given name,
Having climbed the trivial learning curve, only a deliberate wise ass would code garbage like "case i_dont_care:". I don't care about them either. The one obvious way to do it has already been made clear to them. You may as well, e.g., complain that there's nothing to stop a wise ass from writing "-5+6" where everyone else writes "+1".
while _ does not bind to anything, but of what practical importance is that?) .
One obvious way to do it is of major practical importance.
... Besides which, if we use "|" instead of "or" then we can't later allow more general expressions.
Good! The PEP is quite complicated enough already. But if you want to pursue this seriously, you're going to have your work cut for you to explain why "|" is more sacred than "or" with respect to "more general expressions". If you don't want to preclude anything, then you need to invent syntax that has no meaning at all now.
".NAME" grated at first, but extends the idea that dotted names are always constant value patterns to "if and only if". So it has mnemonic value.
How do you get from "." to "iff" ?
See reply to Glenn. Can you give an example of a dotted name that is not a constant value pattern? An example of a non-dotted name that is? If you can't do either (and I cannot)), then that's simply what "if and only if" means.