APP USING FILE

import random
feet_in_mile = 500
meters_in_kilometers = 1000
beatles = ["John Lennon", "Paul McCartney", "George Harrison", "Ringo Star"]

def get_file_ext(filename):
    return filename[filename.index(".") + 1:]

def roll_dice(num):
    return random.randint(1, num)

IN useful_tools files

import useful_tools

print(useful_tools.roll_dice(10))