three_functions.py

# Function with one argument and returns string
def tell_me_your_age(age):
    return f'I am {age} years old.'

# Function with one argument (string) and returns string
def introduce(name):
    return f'HI... My name is {name} and nice to see you!'

# Function with one function as argument and returns its value
def introduce_john(func):
    return introduce('John')