Import variable from module imports only first occurrence

Question

In module1.py, I have a variable, var initialized to an empty string. A function in module1 changes the value of this variable. When I import this variable from module2.py, it only reflects the initial state before the function had changed it, even though I made sure to call the changing function before starting the import.

module1.py

class App(Frame):
    global nums
    nums = []
    def __init__(self, parent):
        Frame.__init__(self, parent, background='lightgreen')
        self.parent = parent
        self.vcmd = parent.register(self.validate)
        self.centerWindow()
        ............

and this is where it gets updated, by a function in same class

nums.append(self.b_eq)

However, on importing nums, I still get an empty array

Answer 1

Python modules act as singletons. If you want to change the value you could either have the function return a result and then call that function. Or, you could create a class in Module1 and instantiate an object. From there you can set the value as desired.