在 Python 列中对对应的行值进行分组

Question

有一个包含 6 列的 .csv 文件。分组是根据第 1 列的重复值进行的；对应列中的所有值（剩余 5 个）应合并为一列。 样本数据

col1    col2            col3        col4    col5    col6
1234    Some Text       Reg1        Value1  Txt      A
2345    Any Text        Reg1        Value2  Txt      B
3456    Some Text       Reg2        Value3  Txt      C
1234    Another Text    Reg3        Value2  Txt      D

Sample Data Screenshot

下面是代码，我正在使用

import csv
import sys

if len(sys.argv) < 2:
   print('To few arguments, please specify input filename')
   sys.exit()

filename = sys.argv[1]

accs = {}
with open(filename, mode='rU') as f:

reader = csv.reader(f, delimiter=',')
for n, row in enumerate(reader):
    if not n:
        # Skip header row (n = 0).
        continue  
    acc, res, reg, col4, col5, col6 = row
    if acc not in accs:
        accs[acc] = list()
    accs[acc].append((res,reg,col4,col5,col6))

def listToStringWithoutBrackets(list1):
return str(list1).replace('[','').replace(']','')

with open('output.csv', 'w', newline='') as csvFile:
writer = csv.writer(csvFile)
for key, value in accs.items():
    writer.writerow([key, listToStringWithoutBrackets(value)])


print("Output file, with a name Output.csv has been created in the current working directory!")

我提到了Sample Code for Group by in Python 下面是我得到的结果（因为我使用了 List 和 Key 作为 Col1 和其他列作为值）

col1    col2
1234    (Some Text,Reg1,Value1,Txt,A),(Another Text, Reg3, Value2, Txt, D)
2345    (Any Text, Reg1, Value2, Txt, B)
3456    (Some Text,Reg2,Value3, Txt,C)

预期结果（需要实际结果）

col1    col2                    col3        col4            col5        col6
1234    Some Text, Another Text Reg1, Reg3  Value1, Value2  Txt, Txt    A,D
2345    Any Text                Reg1        Value2          Txt         B
3456    Some Text               Reg2        Value3          Txt         C

需要不使用第 3 方库的预期（期望）结果。

任何帮助！

Answer 1

import csv

reader = csv.reader(open('1.csv'), delimiter=',')
ans = dict()
for n, row in enumerate(reader):
    if n == 0:
        titles = row
    else:
        num = row[0]
        if num in ans:
            t = ans[num]
            for i in range(1, len(row)):
                t[i].append(row[i])
        else:
            tmp = []
            for other in row:
                tmp.append([other])
            ans[num] = tmp

writer = csv.writer(open("2.csv", 'w'))
writer.writerow(titles)
for row in ans.values():
    tmp = []
    for key in row:
        if isinstance(t, str):
            tmp.append(key)
        else:
            tmp.append(",".join(key))
    writer.writerow(tmp)