How can I use external variables in Python like 'extern int x;' in C?

extern, python

Solution

Simply re-assign the variable in the module:

import myfunc
from myfunc import print_a 

a = 10 

print a

myfunc.a = a

print_a()

Otherwise it is not possible.

Rememeber that python treats modules in a way that is quite different from C. The `import` in python does not "copy the contents" of the file in that place, but it executes the code in the given file and creates a `module` object.

The global variable of the module are the `module` object attributes, which can be modified as I've shown. There is no such notion as "global variable" except for built-ins.

I'd suggest to refactor your code in such a way that you don't have to modify this global variable at all, moving the code that uses `myfunc.a` from `main1` to `myfunc`. The fact that you need such global variable is already a code smell that there's something wrong with your code and you should try to fix it.

Actually there is a way to affect the "global scope" but it is so hackish that I don't even want to mention it. Trust me: you don't want to use it. If people see your code using such a hack you may be in physical danger.

Problem

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