You need to provide more information.

Is your concern that re.match objects aren't matched like dicts are, despite looking like a mapping?

import re

def f(map):
    print(f'input={m["one"]} {m["two"]}')
    match map:
        case {'one': x, 'two': y}:
            print(f"match {x} {y}")
        case _:
            print("no match")

m = re.match("(?P<one>a)b(?P<two>c)", "abc")
d = {'one':0, 'two':1}
f(d)
f(m)

produces:
input=a c
match 0 1
input=a c
no match

I assume you're not reporting a bug, so I'm going to mark this as a feature request.

Oops, slight bug in my code. Use this:

import re

def f(map):
    print(f'input={map["one"]} {map["two"]}')
    match map:
        case {'one': x, 'two': y}:
            print(f"match {x} {y}")
        case _:
            print("no match")

d = {'one':0, 'two':1}
f(d)
m = re.match("(?P<one>a)b(?P<two>c)", "abc")
f(m)

With this output:
input=0 1
match 0 1
input=a c
no match

Looking at PEP 634, the obvious way to add support for this is to have the re.Match object specify Py_TPFLAGS_MAPPING. But I tried that, and then I get this error when using an re.Match object in a match statement:

    case {'one': x, 'two': y}:
         ^^^^^^^^^^^^^^^^^^^^
TypeError: object of type 're.Match' has no len()


Add len() to re.Match objects was rejected when __getitem__ was added to re.Match, in issue 24454.

I haven't explored other ways to support re.Match objects in the match statement.

> There were ideas for exotic matchers such as IsInstance(), InRange(), RegexMatchingGroup() and so on.

https://www.python.org/dev/peps/pep-0622/#custom-matching-protocol

The PEP has some mention about a similar use case in custom match protocol section.

Good catch, @xtreak. I think something like the discussed (but not implemented) custom matching protocol would be required here. __match_args__ won't work, because it's a special attribute only checked on classes, not instances.

Of course, I'm still not sure this is what the original poster is requesting!

But assuming so, this would require a PEP, and should be discussed with the PEP 634 authors.