def is_even(num) :
    # A number is even if it is divisble by 2
    if (num % 2) == 0 :
        return True
    else :
        return False

def is_even_better(num) :
    # A number is even if it is divisble by 2
    if (num % 2) == 0 :
        return True
    
    # In the case that we enter the "if" clause, we return.
    # So we don't actually need an "else" clause
    return False

def is_even_best(num) :
    # since we return true when the expression is true and false
    # when the expression is false, we can actually return the expression!
    return (num % 2) == 0

# Some "dummy" code that actually invokes our functions.
# Later, we will go over "best practices" for writing dummy code like this
print("is_even(3)? " + str(is_even(3)))
print("is_even(22)? " + str(is_even(22)))