Instance vs Class variable oddity

[Chris Angelico]

On Sat, May 18, 2019 at 1:51 PM <jfong at ms4.hinet.net> wrote:
>
> Correct me if I am wrong, please.
>
> I always think that the LEGB rule (e.g. the namespace to look up for) was applied at compile-time, only the binding was resolved "dynamically" at run-time. For example:
>
> def foo():
>     print(x)
>
> foo() will cause a NameError. But after
>
> x = 5
>
> foo() will run correctly.

This is correct; however, this function will fail with UnboundLocalError:

x = 1
def foo():
    print(x)
    x = 2

Function locals ARE locked in at compile time.

ChrisA