Python Write to Text File Dictionary Shows incorrect information

问题

I'm currently testing my code to see if it functions properly, and therefore remove any inconsistencies.

First of all, the code is below:

user_name = str(input("What is your name?"))
last_name = str(input("What is your surname?"))
final_total = int(input("What is your total score?"))

with open('quiz_results.txt') as f:
    for line in f:
        name,val = line.split(":")
        user_scores[name].appendleft(int(val))

    with open("quiz_results.txt", "a+") as f:
        f.write('{}:{}\n'.format(user_name + last_name, final_total))
        print("complete.")

    with open('quiz_results.txt') as f:
        for line in f:
            name,val = line.split(":")
            user_scores[name].appendleft(int(val))

Now, for test data, I added 'Dave' for the user_name, 'Johnson' for the last_name and final totals were 70, 80, 90 and 100 for each go, so I repeated the program 4 times.

When I type in the first result, 70, I get the result I expect in the text file:

DaveJohnson:70

Unusually enough, in the text file, when I type in 80 for the result (with the same name) I get in the text file:

DaveJohnson:80
DaveJohnson:70
DaveJohnson:70

when I should simply get:

DaveJohnson:80
DaveJohnson:70

When I type in 90, I get in the text file:

DaveJohnson:90
DaveJohnson:70
DaveJohnson:70

when I should simply get:

DaveJohnson:90
DaveJohnson:80
DaveJohnson:70

And When I type in 100, I get in the text file:

DaveJohnson:100
DaveJohnson:70
DaveJohnson:70

BUT I should get:

DaveJohnson:100
DaveJohnson:90
DaveJohnson:80

What on Earth is going wrong? Update It is all solved.

回答1:

You are never clearing the user_scores dictionary before rereading the data to it (in the 3rd with statement)

Try to clear the dictionary before reading:

user_scores.clear() 
with open('quiz_results.txt') as f:
    for line in f:
        name,val = line.split(":")
        user_scores[name].appendleft(int(val))

Also: the last with statement does not look right; I guess you'd just want to write all name,score pairs like this:

with open('quiz_results.txt', 'wt') as f :
    for k, v in sorted(user_scores.items()):
        f.write(item[0] + ':' + str(item[1])+'\n')

回答2:

You're reading quizresults.txt twice without reseting the content of user_names. So if a user name/score pair is in the file at the start you read the score into user names, then read it in again. The content of user_scores looks like

start : {'DaveJohnson':[]} #I'm guesing

after first block on first run: {'DaveJohnson':[]}

after second block on first run: {'DaveJohnson':[0]}

after third block on first run: {'DaveJohnson':[70]}

after final block on first run: {'DaveJohnson':[70]}

after first block on second run: {'DaveJohnson':[70]}

after second block on second run: {'DaveJohnson':[70]} (here you append DaveJohnson:80 to your file

after third block on second run [here you re-read DaveJohnson:70 from the file and read DaveJohnson:80] : `{'DaveJohnson':[70,70,80] Out of curiousity, why do you have one script that is reading to a file, appending to it, reading it again and then overwriting it?

来源：https://stackoverflow.com/questions/28520067/python-write-to-text-file-dictionary-shows-incorrect-information

标签

python

dictionary

text-files