Really? It’s best practice to use a magic number rather than a name?

That breaks one of the most fundamental rules for writing good code.

If you really need to compare against a variable, use an "if". The primary benefit of pattern-matching is destructuring.

EDIT: It looks like you actually can match against constants with this PEP, as long as you access your constant with a dot (e.g., HttpError.NotFound). This seems like a perfectly reasonable solution to me.

No it’s not because it’s none obvious and requires a fair amount of boilerplate code. Both of which are usually idioms Python normally tries to avoid.

I guarantee you this will trip up a lot of developers who are either learning the language for the first time or who Python isn’t their primary language.

Worse still, the kind of bugs this will lead to is valid code with unexpected pattern matching, which is a lot harder to debug than invalid code which gets kicked out with a compiler error.

There are PatternSynonyms in Haskell.