python - Pandas :如果列 'E' 的值为 'C'，则更新列 'x' 的值

Question

我有一个像这样的数据框:

           A           B       C       D  E
0      NSPNT  'ACTENRGY'  'XD01'   'DSU'  F
1      NSPNT  'ACTENRGY'  'XD21'   'DSU'  F
2      NSPNT  'ACTENRGY'  'XD22'   'DSU'  F
3      NSPNT  'ACTENRGY'  'XD23'   'DSU'  F
4      NSPNT  'ACTENRGY'  'XD24'   'DSU'  F
5      NSPNT  'ACTENRGY'  'XD25'   'DSU'  F
6      NSPNT  'ACTENRGY'  'XD01'   'DSU'  F
7      NSPNT  'ACTENRGY'   'ACK'  'MISC'  F
8      NSPNT  'ACTENRGY'   'ACU'  'MISC'  F
9      NSPNT  'ACTENRGY'   'ACK'  'MISC'  F
10     NSPNT  'ACTENRGY'   'ACU'  'MISC'  F
11     NSPNT  'ACTENRGY'   'ACK'  'MISC'  F
12     NSPNT  'ACTENRGY'   'ACU'  'MISC'  F
13     NSPNT  'ACTENRGY'   'ACF'  'MISC'  F
14     NSPNT  'ACTENRGY'   'ASF'  'MISC'  F
15     NSPNT  'ACTENRGY'   'DEF'  'MISC'  F
16     NSPNT  'ACTENRGY'   'RLR'   'RLR'  T

我想要实现的是当 Column 'C' =='ACK' 使 Column 'E' = T到目前为止，我已经尝试了以下方法:

import os
import pandas as pd


source_folder = 'D:/NSSCDB/STTS_RCL_Export/'

def editNSPNT():

    for somefile in os.listdir(source_folder):
        if (somefile.startswith(('nsscdb_output_dts')) and 
somefile.endswith(('.txt'.lower()))):

            df = pd.read_csv(source_folder + somefile, encoding='utf-8', names = ['A','B','C','D','E'], header=4)
            #for x in df['C']:
                #if (x == 'ACK'):
                    #df['E'] = 'T'
            #df.E = ["T" if x == "ACK" for x in df.C]
            df.loc[(df.C=='ACK')]['E'] = 'T'

            print(df)



def main():

    editNSPNT()


if __name__== "__main__":
    main()   

我一直在尝试的两种方法都不起作用，有人可以告诉我我做错了什么吗？谢谢。

Answer 1

数据中的单引号是否给您带来了问题？

df.loc[df['C'] == "'ACK'",'E'] = 'T'

使用双引号，

        A           B       C       D  E
0   NSPNT  'ACTENRGY'  'XD01'   'DSU'  F
1   NSPNT  'ACTENRGY'  'XD21'   'DSU'  F
2   NSPNT  'ACTENRGY'  'XD22'   'DSU'  F
3   NSPNT  'ACTENRGY'  'XD23'   'DSU'  F
4   NSPNT  'ACTENRGY'  'XD24'   'DSU'  F
5   NSPNT  'ACTENRGY'  'XD25'   'DSU'  F
6   NSPNT  'ACTENRGY'  'XD01'   'DSU'  F
7   NSPNT  'ACTENRGY'   'ACK'  'MISC'  T
8   NSPNT  'ACTENRGY'   'ACU'  'MISC'  F
9   NSPNT  'ACTENRGY'   'ACK'  'MISC'  T
10  NSPNT  'ACTENRGY'   'ACU'  'MISC'  F
11  NSPNT  'ACTENRGY'   'ACK'  'MISC'  T
12  NSPNT  'ACTENRGY'   'ACU'  'MISC'  F
13  NSPNT  'ACTENRGY'   'ACF'  'MISC'  F
14  NSPNT  'ACTENRGY'   'ASF'  'MISC'  F
15  NSPNT  'ACTENRGY'   'DEF'  'MISC'  F
16  NSPNT  'ACTENRGY'   'RLR'   'RLR'  T