Example of how to dynamically add new attributes to an instance of a class (an object) in Python using setattr()

setattr_example.py

class MyClass:
    def __init__(self, a_number, **kwargs):
        self.a_number = a_number
        for key, value in kwargs.items(): # adding new attributes
            setattr(self, key, value)

if __name__ == "__main__":
    MY_OBJECT = MyClass(1, a_string = "Hello world!")
    print MY_OBJECT.a_number, MY_OBJECT.a_string