Handling errors and exceptions in Hangman python program

问题

print("Welcome to Hangman! Guess the mystery word with less than 6 mistakes!")

words= ['utopian','fairy','tree','monday','blue'] 

while True:
    try:
        i = int(input("Please enter an integer number (0<=number<10) to choose the word in the list: "))
        break
    except ValueError:
        if(i!=int):
            print("Must be an integer input.")
        else:
            print("Empty input.")

Getting into handling exceptions on my Hangman program and once again I've come across another problem. You can run this program and see where I went wrong. I want the value error to be specific, before I had a code like this: except ValueError: print("Value error!") But now I want it to be specific to what the error is. So if the user enters an empty input, I want the program to tell them that they printed an empty string. If they entered a alphabetical letter, I want to catch that error specifically. Hell while we're at it, if they enter an integer out of the list range I want to there to be a caught index error.

回答1:

i is not defined in the except block. You should check whether the user entered nothing before you try to parse the integer:

user_input = input("message")
if not user_input:
    print("Empty input.")
else:
    try:
        i = int(user_input)
        break
    except ValueError:
        print("Must be an integer input.")

回答2:

To check if i is empty, I would first do:

answer = input()  # Save the raw answer

if answer in (None, ''):
    print('Value was empty!')
    continue

Then you can try turning it into an integer:

try:
    i = int(answer)
except ValueError:
    print('Your answer was not an integer')
    continue

Finally, to check if i is in your list of words, you can easily do:

try:
    word = words[i]
except IndexError:
    print("Value was out of range!)
else:
    return word

Stick all of that in a function, and you can use return word like I did to easily exit out of your while True loop, rather than worrying about breaking.

来源：https://stackoverflow.com/questions/19576384/handling-errors-and-exceptions-in-hangman-python-program

标签

python

exception

try-catch