After reading https://discuss.python.org/t/when-should-we-assume-callable-types-are-method-descriptors/92938/9, I was curious to see if I could write structural method type, dual to the nominal ones in the types stdlib. But I ran into a bit of an issue:

from typing import Protocol

class HasSelf(Protocol):
    @property
    def __self__(self, /) -> object: ...

class A:
    def f(self) -> None: ...

reveal_type(A.f.__self__)   # ✅ type[A]
reveal_type(A().f.__self__) # ✅ A
f1: HasSelf = A.f           # ❌ reportAssignmentType
f2: HasSelf = A().f         # ❌ reportAssignmentType

• Type of "A.f.__self__" is "type[A]"
  

• Type of "A().f.__self__" is "A"
  

• Type "(self: A) -> None" is not assignable to declared type "HasSelf"
    "FunctionType" is incompatible with protocol "HasSelf"
      "__self__" is not present  (reportAssignmentType)
  

• Type "() -> None" is not assignable to declared type "HasSelf"
    "FunctionType" is incompatible with protocol "HasSelf"
      "__self__" is not present  (reportAssignmentType)
  

pyright playground

And I'm guessing that "__self__" is not present is not meant in a spiritual-philosophical sense :)