Compare object instances of different classes for equality by their attributes

Question

I have two classes:

class A:                    
def __init__(self, name, id=None, created_at=None):
    self.name = name
    self.id = id
    self.created_at = created_at
def __str__(self):
    return f"{self.id} {self.name} {self.created_at}"
def __repr__(self):
    return f"{self.id} {self.name} {self.created_at}"
def __eq__(self, other):
    if (isinstance(other, A)):
        return self.id == other.a_id

And

    class B:                    
def __init__(self, id, a_id, created_at=None):
    self.id = id
    self.a_id = a_id
    self.created_at = created_at
def __str__(self):
    return f"{self.id} {self.name} {self.created_at}"
def __repr__(self):
    return f"{self.id} {self.name} {self.created_at}"
def __eq__(self, other):
    if (isinstance(other, B)):
        return self.a_id == other.id

My goal is to get a == b is true if a.id == b.a_id . Like comparing a primary key of a with a foreign key of b. I know eq is not working because I want to compare two different classes. Is there a way to do this in python 3?