Python csv：合并具有相同字段的行

Question

鉴于两个单元格包含相同的数据，我正在尝试将多行 csv 数据合并为一长行。例如，采用以下 csv：

one, two, three
1, 2, 3
4, 5, 6
7, 8, 9
1, 1, 1
4, 4, 4

如果两行在 row[0] 处共享相同的值，我希望将第二行附加到第一行。所以我的最终产品应该是这样的：

one, two, three
1, 2, 3, 1, 1, 1
4, 5, 6, 4, 4, 4
7, 8, 9

这是我目前的尝试：

import csv

uniqueNum = []
uniqueMaster = []
count = -1
with open("Test.csv", "rb") as source:
    reader = csv.reader(source)
    header = next(reader)
    for row in reader:
        if row[0] not in uniqueNum:
            uniqueMaster.append(row)
            uniqueNum.append(row[0])
            count = count + 1
            for row in reader:
                if row[0] in uniqueNum:
                    uniqueMaster[count].append(row)

with open("holding.csv","wb") as result:
    writer = csv.writer(result)
    writer.writerow(header)
    for row in uniqueMaster:
        writer.writerow(row) 

我觉得一切正常，但我的脚本只输出以下内容：

one, two, three
1, 2, 3, ['1', '1', '1']

这显然是错误的，原因有两个。首先，它不会遍历整个 csv，其次，附加值被压缩到一个单元格中，而不是单个单元格中。如果有人对让它正常工作有任何建议，我将不胜感激！

Answer 1

改用字典。从你的代码中间开始（假设我已经声明了一个名为 my_dict 的字典）：

 for row in reader:
    if row[0] in my_dict.keys():
       my_dict[row[0]].extend(row)
    else:
       my_dict[row[0]]=row
  #...now we are at the bottom of your code, writing to the csv
 for v in my_dict.values():
    writer.writerow(v)

Answer 2

import csv

csv_dict = {}

with open("Test.csv", "r") as source:
    reader = csv.reader(source)
    header = next(reader)

    for row in reader:
        if row[0] in csv_dict:
            csv_dict[row[0]] += row
        else:
            csv_dict[row[0]] = row