"non-essential difficulty" - case enforcing?

[Edward S. Vinyard]

>In summary, case-enforcing seems like it could be a solution, I just
>don't know how it would work :)

Consider these possible difficulties:

class a:
    x = 0

def a():
    return 1

a = 2

or

class A:
    x = 0

b = 0
b = A

How do you handle these situations without forcing a variable to be of a
fixed type (class, function, instance) over the course of its lifetime?

Ed