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I have this code running in a number guessing game I have written, it runs perfectly fine if the player follows the instructions, but as we all know users never do. If the user enters just a space or any string thats not the word hint then it crashes saying invalid literal for int() with base 10: when trying to convert the value of guess to an integer. Is there any way around this or am I just going to have to live with the crashes?

while repeat==1:
    repeat=0
    level1number=str(level1number)
    guess=input("What is your guess? ")
    guess=guess.lower()
    if guess==level1number:
        print("Well done, You have guessed my number!")
    elif guess=="hint":
        print("Hints are not available until level 3")
        repeat=1
    elif guess!=level1number:
        print("Sorry that is not my number, you have lost a life. :(")
        lives=lives-1
        repeat=1
        if lives<=0:
            print("You have lost all your lives, so this means I win")
            print("The program will now end")
            exit()
            input("")
        level1number=int(level1number)
        guess=int(guess)
        if guess<level1number:
            print("The target number is higher")
        else:
            print("The target number is lower")
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9
  • Catch the exception and keep asking a valid value. Commented Oct 20, 2016 at 9:16
  • There are many ways around this. The easiest is probably using a while loop and try except block to keep asking the user for input if it can't be converted to int. Commented Oct 20, 2016 at 9:16
  • it runs the not equal to section of the loop if its not the target number or the word hint, causing the crash Commented Oct 20, 2016 at 9:18
  • You shouldn't cast level1number to str and guess should be an integer as soon as possible. Commented Oct 20, 2016 at 9:18
  • 1
    guess the error should be coming from core "guess=int(guess)" Commented Oct 20, 2016 at 9:21

2 Answers 2

Reset to default
4

Use something as

if guess.isdigit() ...

(method isdigit() returns true if and only if all characters of a given string are digits, i.e. 0 to 9).

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2 Comments

This is the best answer (so far); while it returns False then make it keep asking the user for his input again.
@MarianD Do you know of a signed version of this? For instance '-1'.isdigit() will return false but can evaluate to a number. '-1'.isnumeric() will also return false
1 
while repeat==1:
    repeat=0
    level1number=str(level1number)
    guess=input("What is your guess? ")
    guess=guess.lower()
    if guess==level1number:
        print("Well done, You have guessed my number!")
    elif guess=="hint":
        print("Hints are not available until level 3")
        repeat=1
    elif guess!=level1number:
        print("Sorry that is not my number, you have lost a life. :(")
        lives=lives-1
        repeat=1
        if lives<=0:
            print("You have lost all your lives, so this means I win")
            print("The program will now end")
            exit()
            input("")
        level1number=int(level1number)
        try:
            guess=int(guess)
            if guess<level1number:
                print("The target number is higher")
            else:
                print("The target number is lower")
        except:
            print("Try again. Not a number")

Using try/except block would solve your problem. Have a look

Edit: In the question. you mentioned that you get an error when something other than a number is entered. Actually, it is an exception that is thrown when your code tries to convert your input string to a number when it is not possible(guess = int(guess)) due to the input not being a number, just like a space. So, what my code does, is that it catches the exception, and does not allow the program to terminate with the exception.

Just try it once. I know you are beginner but it is better to learn about exception handling as soon as possible, before you write more and more complex codes and applications.

Hope it helps!!

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2 Comments

thanks, im not a professional and i have never heard of try/except
i have accepted the answer, just my reputation isnt high enough for it to be visible

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