Python scope, dictionary and variables difference?

Question

Python scope I have the same question but slightly different.

number = 0
def incrementNumber():
    number += 1

This one above does not work but this one below does why? Both are outside the function scope.

number = {'num':0}
def incrementNumber():
    number['num'] += 1

First one works if I add the variable as global

number = 0
def incrementNumber():
    global number
    number += 1

Answer 1

Check out this blog post, it's similar to what you're doing. Specifically adam's comment.

You don't assign to dictionaryVar, you assign to dictionaryVar['A']. So it's never being assigned to, so it's implicitly global. If you were to actually assign to dictionaryVar, you'd get the behavior you were "expecting".