# utils.py — your own module
# place in the same folder as main.py
# redhorndev.com

def greet(name):
    return f"Hello, {name}."

def celsius_to_fahrenheit(c):
    return c * 9/5 + 32

def is_even(n):
    return n % 2 == 0

if __name__ == "__main__":
    # runs only when utils.py is executed directly
    # not when imported
    print(greet("Raven"))
    print(celsius_to_fahrenheit(100))
    print(is_even(4))