Creating objects on the fly in Python

Question

Why do i need

class DummyObject(object): pass 

to make

 dummy = DummyObject() dummy.foo = 42 

Why is this not legal in Python?

 dummy = object() dummy.foo = 42 

Which gives an error:

 Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'object' object has no attribute 'foo'