Question

这是我为孩子们做的简短测验。该程序的主体工作正常。但它必须将每个用户的三个最新correctAnswers保存到.txt文件中，删除旧分数。

我花了很长时间试图找出如何使用JSON或者Pickle作为我的代码，但我不知道如何将它们用于我的代码。任何帮助将不胜感激。

if usersGroup == a:
    with open("groupA.txt","a+") as f:
        f.write("\n{}:Scored {} in {} seconds.".format(username,correctAnswers,timeTaken))

elif usersGroup == b:
    with open("groupB.txt","a+") as f:
        f.write("\n{}:Scored {} in {} seconds.".format(username,correctAnswers,timeTaken))

elif usersGroup == c:
    with open("groupC.txt","a+") as f:
        f.write("\n{}:Scored {} in {} seconds.".format(username,correctAnswers,timeTaken))
else:
    print("Sorry, we can not save your data as the group you entered is not valid.")

Answer 1

如果您要一次更新三个分数，则需要覆盖不附加：

open("groupA.txt","w")

保持上一次运行的最后两次并写下最新的单一分数：

with open("groupA.txt","a+") as f:
    sores = f.readlines()[-2:] # get last two previous lines
    with open("groupA.txt","w") as f:
        # write previous 2
        f.writelines(scores)
        # write latest
        f.write("\n{}:Scored {} in {} seconds.".format(username,correctAnswers,timeTaken))

可能更容易pickle或json dict并保留一个分数列表，用最新的分数替换最后一个分数。

import pickle
from collections import defaultdict

with open('scores.pickle', 'ab') as f:
    try:
        scores = pickle.load(f)
    except ValueError:
       scores = defaultdict(list) 

    # do your logic replacing last score for each name or adding names

   with open('scores.pickle', 'wb') as f:
       # pickle updated dict 
       pickle.dump(f,scores)

如果您希望人类可读的格式使用json.dump和普通的dict，您可以使用dict.setdefault而不是使用defaultdict的功能：

import json


with open('scores.json', 'a') as f:
    try:
        scores = json.load(f)
    except ValueError:
        scores = {}
        # add user if not already in the dict with a list as a value
        scores.setdefault(name,[])
         # just append the latest score making sure when you have three to relace the last
        scores[name].append(whatever)
 #   do your logic replacing last score for each name or adding names

    with open('scores.json', 'w') as f:
       json.dump(scores,f)

Python：只保存三个最新分数

1 个答案: