why is 'ord' seen as an unassigned variable here?

Question

I hope it\'s not a duplicate (and at the same time it\'s difficult to tell, given the amount of questions with such errors, but which are basic mistakes), but I don\'t under

Answer 1

Just to demonstrate what's going on with the compiler:

def f():
    if False:
        ord = None
    c = ord('a')

  4           0 LOAD_FAST                0 (ord)
              3 LOAD_CONST               1 ('a')
              6 CALL_FUNCTION            1 (1 positional, 0 keyword pair)
              9 STORE_FAST               1 (c)
             12 LOAD_CONST               0 (None)
             15 RETURN_VALUE

Access to a is using LOAD_FAST, which is used for local variables.

If you set ord to None outside your function, LOAD_GLOBAL is used instead:

if False:
    ord = None
def f():
    c = ord('a')

  4           0 LOAD_GLOBAL              0 (ord)
              3 LOAD_CONST               1 ('a')
              6 CALL_FUNCTION            1 (1 positional, 0 keyword pair)
              9 STORE_FAST               0 (c)
             12 LOAD_CONST               0 (None)
             15 RETURN_VALUE