Lists, Tuples, and Statistics Program Try-Except Block Error

Question

I am working on a Lists, Tuples, and Statistics Program for my intro class, and am having some difficulty with a try-except block. The program we are supposed to make is supposed to ask for the user to name a file to input, and then give some information about the numbers in that file. I have all of the information displays working correctly, but can't write the try-except block. The program needs to accept only the file name "new_numbers.txt" and nothing else.

Here is the top portion of my code:

    def main():
        #Get the name of the file from the user
        while(True):
                try:
                    input("Enter the name of the file you would like to open: ")
                except ValueError:
                    print("That file does not exist. Please enter a valid file.")
                    break

Answer 1

You need to assign the value from input, and try to open it to see if the file in question is around...:

def main():
    #Get the name of the file from the user
    while(True):
        try:
            fn = input('Enter the name of the file you would like to open: ')
            f = open(fn)
        except IOError:
            print('File {} does not exist. Please enter a valid file.'.format(fn))
        else:
            break

Also note that you should break only when there is no more error; and in that case the open file object is ready as variable f.