if-else Statements in Python

Why am I getting an error that I don't have the correct values in my variables?? (If someone could read over my code, I would appreciate it.) Thanks in advance!

number1 = -50
number2 = 53
number3 = 78
def largest(num1, num2, num3):
    if (num1 > num2) and (num1 > num3):
        largest_num = num1
    elif (num2 > num1) and (num2 > num3):
        largest_num = num2
    else:
        largest_num = num3
    print("The largest value is : ", largest_num)
def smallest(num1, num2, num3):
    if (num1 < num2) and (num1 < num3):
        smallest_num = num1
    elif (num2 < num1) and (num2 < num3):
        smallest_num = num2
    else:
        smallest_num = num3
    print("The smallest value is : ", smallest_num)
largest(number1, number2, number3)
smallest(number1, number2, number3)