Types of class method aliases

[whoami730]

I have a sample class -

class X:
    def method1(self):
        return 1

    method2 = method1

reveal_type(X.method1)
reveal_type(X.method2)

Here is what mypy says -

$ mypy a.py
a.py:7: note: Revealed type is "def (self: a.X) -> Any"
a.py:8: note: Revealed type is "def (self: a.X) -> Any"

And here is what pyright/pylance reports -

Type of "X.method1" is "(self: X) -> Literal[1] - Pylance
(method) def method1(self: X) -> Literal[1]
...
Type of "X.method2" is "(self: X) -> Literal[1] - Pylance
(variable) def method2(self: X) -> Literal[1]

I wonder if it is possible to ensure that the second method is also shown as (method) instead of as (variable)? Maybe via type hints or via some other way?

[erictraut]

The portion that you see in parentheses is not the symbol type. It indicates the type of the declaration used to declare the symbol. In your example, method1 uses a method declaration (a def statement within a class body) and method2 uses a variable declaration (an assignment statement in a class body). If you want method2 to be displayed as (method), you'd need to change it to a def statement. Something like this:

    def method2(self):
        return self.method1()

[whoami730]

But that would mean I would lose the function documentation, needing to rewrite it.

[erictraut]

functools.wrap is commonly used to copy function metadata like docstrings.