How to change value of variable from a different .py file in Python

Question

From a file foo.py , I want to change the value of a variable which's placed in a different file, let's say bar.py .

I've tried to do it importing the variable, but it seems that it's imported not as reference.

Just examples:

bar.py :

age = 18

foo.py :

from bar import age

def changeAge(age, newAge):
    age = newAge

changeAge(age, 19)

I've also tried to pass age as parameter from bar.py , but same result, it's not passed by reference so its value is not changed.

bar.py :

from foo import changeAge

age = 18

changeAge(age, 19)

As I said, it didn't work at all. I know I can reach this returning the var from the function, but it will probable make me to change a lot of code and, why not, I want to know if there is a way to do what I need, I'm still a beginner in Python. Another way is to wrapper the variable in an object, a list or something like that, but it doesn't seem too elegant.

Answer 1

def changeAge(newAge):
    import bar
    bar.age = newAge

Answer 2

If you just want to change the value of 'age' you can do the following

age = 18

import bar

def changeAge(newAge):
    bar.age = newAge

changeAge(19)

Answer 3

You forgot to return newAge.

from bar import age

def changeAge(age, newAge):
    age = newAge
    return newAge

print changeAge(age, 19)

Prints out 19 as expected.