Question

我目前正在制作一个测验作为我和我的朋友之间的竞赛，并学习更多关于我相对较新的编程。我的程序旨在为使用测验的每个用户保留最后3个结果，并用最新的结果替换最旧的结果。我已经达到的当前阶段是能够检查用户是否在文件中有他们的名字，如果没有正常写入文件。

    if team == 'Team 1':
        path = 'team1scores.csv'

    elif team == 'Team 2':
        path = 'team2scores.csv'

    elif team == 'Team 3':
        path = 'team3scores.csv'

    else:
        print("--Error Defining File Path--")

with open(path, 'rt') as csvfile:
    ver_read = csv.reader(csvfile, delimiter =",")
    ver_write = csv.writer(csvfile, delimiter =",")
    for row in ver_read:
        if user in row:
            row_data = list(ver_read)
            row_len = len(row_data)
            if row_len >= 3:
            >>> The Problem is here

        else:
            with open(path, 'a+', newline='') as csvfile:
                csvwriter = csv.writer(csvfile, delimiter=',')
                csvwriter.writerows(datacsv)

我对程序的问题是能够替换结果，比如我已经在我的csv文件中有3个输入的数据。这些需要保存在两个不同的列中。因为我打算包括排序功能。

Jake,5
Jake,7
Jake,2
Max,9
Lee,8

我已经根据上面的代码进行了多次实验，但是一旦程序达到替换信息的情况，我就很困惑。到目前为止，我已经能够覆盖整个文件，但不能覆盖特定的数据。

接下来的步骤中是否需要 ver_write ？

修改我现在有一个更新版本，但仍然有同样的问题，这个程序改编自2ps的答案，以符合我的标准。它仍然需要覆盖并需要打印到两个不同的单元格以获取名称和分数。基础是我需要的，但它不会起作用。

from collections import OrderedDict
user_data = OrderedDict()
data_to_write = []
with open(path, 'r+') as csvfile:
    ver_read = csv.reader(csvfile, delimiter =";")
    for x, row in enumerate(ver_read):
        if user == row[0]:
            user_data[x] = row
        else:
            data_to_write.append(row)
    if len(user_data) > 2:
        keys = user_data.keys()[-2:]
        for x in keys:
            data_to_write.append(user_data[x])
            data_to_write.append(datacsv)
            with open(path, 'w') as csvfile:
                ver_write = csv.writer(csvfile, delimiter=",")
                ver_write.writerows(data_to_write)
    else:
        with open(path, 'a+', newline='') as csvfile:
            csvwriter = csv.writer(csvfile, delimiter=',')
            csvwriter.writerows(datacsv)

我在这里做了一些根本错误的事情吗？

Answer 1

据我所知，你是cannot change one row in a file。所以你必须重写完整的文件。

我不知道您如何插入新数据，但您可以执行以下操作：

import csv

# Assuming new score
new_score = ['Jake', '3']

# Open the file containing the scores
with open('scores.csv', 'r') as csvfile:
    ver_read = csv.reader(csvfile, delimiter=',')

    # Make a dict that will contain the scores per person        
    names = {}
    for row in ver_read:
        # Grab the name and the score
        name,score = list(row)

        # If it's not in names yet, put it in and make it a list
        if name not in names:
            names[name] = []

        # Append the score to the name list
        names[name].append(score)

# Add the new score
names[new_score[0]].append(new_score[1])

with open('scores.csv', 'w') as csvfile:
    # Loop the names in the names dict
    for name in names:

        # If the person has more than 3 scores, only take the last 3
        if len(names[name]) > 3:
            names[name] = names[name][-3:]

        # For each score, print it
        for score in names[name]:
            print('{},{}'.format(name, score))
            #ver_write.writerow([name, score])

在：

Jake,5
Jake,7
Jake,2
Max,9
Lee,8

新分数：

Jake,3

输出：

Jake,7
Jake,2
Jake,3
Max,9
Lee,8

Answer 2

你可以尝试这样的事情：

data_to_write = []
with open(path, 'r+') as csvfile:  # read-write mode for file
    ver_read = csv.reader(csvfile, delimiter =",")
    row_data = list(ver_read)

    for row in row_data:
        if user in row:
            if row_data.index(row) >= 3:    # if we found the user in a row after 3
                row = []    # change the information here to whatever suits you
            else:
                row = []    # or here depending on your logic
        data_to_write.append(row)   # store it for afterwards

    # finally write the changes to file
    ver_write = csv.writer(csvfile, delimiter=",")
    ver_write.writerows(data_to_write)

Answer 3

from collections import OrderedDict
user_data = OrderedDict() # dict to hold all matching rows for the user, keyed off of line number
data_to_write = []
with open(path, 'r') as csvfile:  # read-write mode for file
    ver_read = csv.reader(csvfile, delimiter =",")
    for x, row in enumerate(ver_read):
        if user == row[0]:
            user_data[x] = row
        else:
            data_to_write.append(row)   # store it for afterwards
    if len(user_data) >= 3:
        keys = user_data.keys()[-2:] # Grab the last two scores in the file
        for x in keys:
            data_to_write.append(user_data[x])
        # Write the contents of the new score here:
        data_to_write.append(. . . . .)
with open(path, 'w') as csvfile:
    # finally write the changes to file
    ver_write = csv.writer(csvfile, delimiter=",")
    ver_write.writerows(data_to_write)

替换csv文件中的特定数据

3 个答案: