python - 根据索引值在列 'A' 中插入 Null

Question

我有一个索引号为“l1”的列表，我想根据这些索引号将“A”列中的值替换为 NaN

当前数据

Index                A
0        Reviewer: Newbie | 35-44 on Treatment for 1 
1        Reviewer: 45-54 on Treatment for less than 1 
2        Reviewer: Ocetech| 65-74 Male on Treatment 
3        Reviewer: virleo| 55-64 Female on Treatment 
4        Reviewer: Diane perrin| 65-74 on Treatment for

l1 = [ 1 , 3, 4]

预期输出

Index                A
0        Reviewer: Newbie | 35-44 on Treatment for 1 
1        NaN 
2        Reviewer: Ocetech| 65-74 Male on Treatment 
3        NaN
4        NaN

Answer 1

使用 .loc 在数据框中定位 l1 中的索引，然后分配 np.nan 如下:

import numpy as np
df.loc[l1,'A'] = np.nan