I’m encountering an issue with my Python code using Pyright type checker, specifically when I try to remove Any from the return type declaration.

Look/read this question first: Handling Python Type Checker Errors with Return Type Declarations (fields default values)

Error message:

Function with declared return type "int" must return value on all code paths. "None" is incompatible with "int".

What about this case? I still get the same error as above(question from stack overflow), even though my classes do not contain any None.

class Exp:
    pass

@dataclass
class Const(Exp):
    value: int

@dataclass
class Negate(Exp):
    value: Exp

@dataclass 
class Add(Exp):
    value1: Exp
    value2: Exp

@dataclass
class Multiply(Exp):
    value1: Exp
    value2: Exp


def eval_exp_old(e: Exp) -> int | Any:
    match e:
        case Const(i):
            return i
        case Negate(e2):
            return -eval_exp_old(e2)
        case Add(e1, e2):
            return eval_exp_old(e1) + eval_exp_old(e2)
        case Multiply(e1, e2):
            return eval_exp_old(e1) * eval_exp_old(e2)
        

test_exp: Exp = Multiply(Negate(Add(Const(2), Const(2))), Const(7))
# -28
old_test = eval_exp_old(test_exp)

I appreciate any advice.