python global namespace not accessible

Question

I can run API.py, but not the APP.py in the same directory. The error is "NameError: name 'a' is not defined". Is global() really global?

API.py:

class Entity():
    def __init__(self,name,value):
        globals()[name]=value

if __name__ == '__main__':
    Entity('a',1)
    print(a)

APP.py

from API import Entity

if __name__ == '__main__':
    Entity('a',1)
    print(a)

Python does not have "true" global variables, only module-level "global_. Most consider this a good thing. Why do you need this? — juanpa.arrivillaga, Apr 11 '19 at 16:37

score 1 · Answer 1 · answered Apr 11 '19 at 16:34

Globals are only accessible by a every function in a module, but not by functions in other imported modules.

Instead of having Entity setting a global variable directly, perhaps you could have it return the value and then write code in APP.py to set the value globally.

The alternative is to have your global variable in a shared module that is imported by everyone else, and then every module will have read/write access to it.

python global namespace not accessible

1 Answers1