[Tutor] Binary/Decimal convertor

[Ghadir Ghasemi]

Hi, I made a program called binary/denary convertor. Can anyone tell me about how I could stop the user entering a binary number with more than 8 numbers or 8 bit by repeating the question over and over until they do enter a correct binary number( 8-bit or less)
Here is the code. I started off by entering 'len' function.

def add_binary_numbers(num1, num2):
    return num1 + num2

num1 = int(input('please enter the first 8 bit binary number: '),2)
if len(num1) > 8:
    print("please enter an 8 bit binary number")
return int(num1,2)
num2 = int(input('please enter the second 8 bit binary number: '),2)
result = add_binary_numbers(num1, num2)
print('the result is', bin(result)[2:])

Thanks, Ghadir