python 3.x - addition between classes using radd method

Question

I have two different classes, and I want to define the addition of them only in one class, and define both __add__ and __radd__ for that class (in my example below, that's ExampleClass2. I DO NOT want to create an __add__ method that works for ExampleClass1 to add ExampleClass2.

As it is right now it just ignores it. I also tried with raising error, but that didn't work either.

class ExampleClass1:
    def __init__(self, data):
        self.data = data
        
    def __add__(self, other):
        if isinstance(other, int):
            print('other was an int')
        
        
class ExampleClass2:
    def __init__(self, data):
        self.data = data
        
    def __add__(self, other):
        if isinstance(other, ExampleClass1):
            print("it's working")
            
    __radd__ = __add__
    
a = ExampleClass1('q')

b = ExampleClass2('w')

a+b

Answer 1

__radd__ is only called if the left object does not have an __add__ method, or that method does not know how to add the two objects (which it flags by returning NotImplemented). Both classes have an __add__ method, which do not return NotImplemented. Therefore the __radd__ method would never be called.