Multiple Error Handling on Python

Question

I was wondering how I would handle multiple errors on python.

For example:

The user enters an integer between 0 and 9. If the integer is out of range then the program will say so and ask for another input until a valid input is obtained. If the input is not an integer then the program will say it is an invalid input and ask for another input until a valid input is obtained. Finally, if no input is provided, then the program would say there needs to be an input, and ask for another input until a valid input is obtained. These three errors must be distinguished for a single input variable.

Thanks for the help in advance

Answer 1

If you want to validate user input against several criteria and keep asking for new input if any of them are failed, you probably want a loop that keeps going until you have a valid result:

result = None
while result is None:
    input_str = input("Enter an integer between 0 and 9:")
    if input_str == "":
        print("An empty input is not valid.")
    else:
        try:
            result = int(input_str)
            if not 0 <= result <= 9:
                print("That number out of bounds.")
                result = None
        except ValueError:
            print("That is not an integer.")

# do stuff with result here