main.py

class MyClass:
    def __init__(self, value1, value2):
        self.value1 = value1
        self.value2= value2

if __name__ == "__main__":

    init_class_my_class = MyClass("my_new_value1", "my_new_value2")
    print(init_class_my_class.__dict__)

    init_class_my_class.value3 = "my_new_value3"

    print(init_class_my_class.__dict__)