Sharing variables across modules

[j.crater]

Hey all,
today I somehow managed to get stuck with getting a variable in one module changed by a function in another module - something I had working last time I wrote multi-module scripts.

Simplifying the code (otherwise requiring Kivy to run), I have:

main.py:

from kivy.app import App
import parameters
import utils


class MainApp()
    def on_start(self): # runs when application starts
        utils.read_config_file() # reads config text file and should modify parameters dictionary accordingly
        Window.clearcolor = hex2color(parameters.parameters["background_color"]) # should use new color value instead of default one

if __name__ == '__main__':
    MainApp().run()

parameters.py:

# dictionary with default values
parameters= {
    "config_file": "config.txt",
    "width": "800",
    "height": "400",
    "background_color": "#FFFFFF",
}

utils.py

import parameters


# reads config.txt file and should overwrite default values in parameters dictionary with those found in file
def read_config_file():
    with open(parameters.parameters["config_file"], "r") as config_file:
        for line in config_file:
            if line == "\n" or line == "":
                continue
            key, value = line.strip().split() 
            parameters.parameters[key[:-1]] = value.strip()       

I would like the parameters dictionary (in parameters.py module) to be referenced from other modules, so the variables can be shared.
First on application startup, a configuration text file is to be read and values in parameters dictionary overwritten with those found in file.
However, the values in dictionary are not affected by read_config_file() function in utils.py. The values from file are read correctly though.

What am I missing? Is there some variable/module naming conflict I overlooked? Am I doing the imports incorrectly?
Thanks for hints,
JC