Python: access variable in a function in another file

Question

I have two files:

lib.py

global var
def test():
    var = "Hello!"
    return

test.py

from lib import *
test()
print(var)

But despite having them in the same folder, when I run test.py, I get the following error:

Traceback (most recent call last):
  File "C:\Test\test.py", line 5, in <module>
    print(var)
NameError: name 'var' is not defined

How can I access this variable in a function in another file?

Answer 1

You need to declare the variable as global in the scope which it is used, which in this case is the function test() :

def test():
  global var
  var = "Hello!"

Note that the final return is not necessary, since it is implicit at the end of a function. Also, var is declared in the global scope of the module, so it won't be imported automatically by from lib import * since it's created after the module has been imported.

Returning var from the function is probably a better solution to use across modules:

def test():
  var = "Hello!"
  return var

var = test()
print(var) # Hello!

Answer 2

I recommend the following:

lib.py

def test():
    return "Hello!"

test.py

from lib import *
var = test()
print(var)