How can I make the imported modules use the same objects as my main?

Question

My setup is this. I have an engine.py that defines a lot of variables and custom functions that I script and modify in external script.customextension . I am using imp.load_source('script', 'script.customextension') to import my external scripts, but when I do that all the variables and functions can not be accesssed from the external module.

I have then tried writing this as the first line in the external script: from engine import * but then I am re-instantiating all the objects and losing the ones already created that I need access to.

A gross simplification is the following

file engine.py

a = 10

def f(myval):
    global a
    a = myval
    print(a)

if __name__ == '__main__':
    imp.load_source('script', 'script.ext')

and file script.ext has this single line

f(20)

Results in this when running engine.py:

NameError: name 'f' is not defined

Where what I wanted was:

20

Answer 1

Here's ugly:

import __main__ as main

main.f(20)

Answer 2

I found that this solution could be used instead of importing modules (see exec )

    _file = open('script.ext')
    for line in _file:
        exec(line)