Question

I am very new to python, and I am hoping I didnt miss a fix for this somewhere else. I have a simple program that was one of the practice excercises in a book I purchased and I am running into an issue. I have a program that opens a file and writes it to a list. Then a user can update the list with input, and when a user exits it updates the list with the latest content. Everything works fine except the sort option. It shows the scores from the file with a single quote infront of them, and the scores updated while the program was running without. It also doesn’t sort them at all. I have tried many different way to do this without fail. I am sure this is not that important in the long run, but I wanted to figure it out.

Here is the code

# High Scores
# Demonstrates list methods

scores = []
try:
    text_file = open("scores.txt", "r")
    for line in text_file:
        scores.append(line.rstrip("\n"))

    text_file.close()

except:
    raw_input("Please verify that scores.txt is placed in the correct location and run again")



choice = None
while choice != "0":


    print \
    """
    High Scores Keeper

    0 - Exit
    1 - Show Scores 
    2 - Add a Score
    3 - Delete a Score 
    4 - Sort Scores
    """

    choice = raw_input("Choice: ")
    print

    # exit
    if choice == "0":
        try:
            output_file = open("scores.txt" , "w")
            for i in scores:
                output_file.write(str(i))
                output_file.write("\n")

            output_file.close()
            print "Good-bye"
        except:
            print "Good-bye.error"

    # list high-score table
    elif choice == "1":
        print "High Scores"
        for score in scores:
            print score

    # add a score
    elif choice == "2":
        score = int(raw_input("What score did you get?: "))
        scores.append(score)

    # delete a score
    elif choice == "3":
        score = int(raw_input("Delete which score?: "))
        if score in scores:
            scores.remove(score)
        else:
            print score, "isn't in the high scores list."

    # sort scores
    elif choice == "4":
        scores.sort()
        scores.reverse()
        print scores

    # some unknown choice
    else:
        print "Sorry, but", choice, "isn't a valid choice."


raw_input("\n\nPress the enter key to exit.")

Answer 1

When you add scores from the file, you’re adding them as strings: scores.append(line.rstrip("\n")). But when you add scores during the program, you’re adding them as integers: int(raw_input("What score did you get?: ")).

When Python sorts a list containing both strings and integers, it’ll sort the strings according to character order (so '1' < '12' < '3'), and sort the integers separately, putting the integers before the strings:

>>> sorted([1, 8, '11', '3', '8'])
[1, 8, '11', '3', '8']

Presumably it’s printing out a single quote after the characters as well as before, as it does here (indicating that it’s a string).

So, when you’re reading the file at the start, turn them into an integer just like you do when you read user input.

---

Some other tips:

• scores.sort(reverse=True) will sort in reverse order without having to go through the list twice.
• It’s generally a bad idea to do except:: that’ll catch absolutely any problem with the program, including the user hitting ^C to try to quit, the system running out of memory, etc. You should do except Exception: as a catch-all to get exceptions that it’s possible to recover from but not those kinds of system errors, or a more specific exception when you want to handle only certain types.