pandas在基于其他列的列中删除值

Question

有没有办法在df中删除单个条目？

df1:
ID  Count1  Value1  Count2  Value2
111 5   10  5   25
112 4   15  6   25
113 6   7   4   10
114 3   8   2   1
115 7   1   8   10

如果Count1＆lt;我想删除任何Value1如果Count2＆lt; 5，则删除任何Value2。结果是这样的：

ID  Count1  Value1  Count2  Value2
111 5   10  5   25
112 NA  NA  6   25
113 6   7   4   NA
114 NA  NA  NA  NA
115 7   1   8   10

谢谢！

Answer 1

使用loc

df.loc[df['Count1'] < 5, ['Count1','Value1']] = np.nan
df.loc[df['Count2'] < 5, ['Count2','Value2']] = np.nan

    ID  Count1  Value1  Count2  Value2
0   111 5.0     10.0    5.0     25.0
1   112 NaN     NaN     6.0     25.0
2   113 6.0     7.0     NaN     NaN
3   114 NaN     NaN     NaN     NaN
4   115 7.0     1.0     8.0     10.0

Answer 2

使用mask：

df[['Count1','Value1']] = df[['Count1','Value1']].mask(df.Count1 < 5)
df[['Count2','Value2']] = df[['Count2','Value2']].mask(df.Count2 < 5)

print (df)
    ID  Count1  Value1  Count2  Value2
0  111     5.0    10.0     5.0    25.0
1  112     NaN     NaN     6.0    25.0
2  113     6.0     7.0     NaN     NaN
3  114     NaN     NaN     NaN     NaN
4  115     7.0     1.0     8.0    10.0

Answer 3

试试这个：

df1 = df1 [df1 ['Count1']＆lt; 5＆amp; df1 ['Count2']＆lt; 5]