如何使用if语句在pandas中保存文件？

Question

我只想在字段2和字段3不匹配时保存行。例如在id“AAA”中

id    field2    field3
AAA    SRE        SRE
AAA    FSD        FRE
AAA    TUE        TUE
ABA    SDE        SDE
AAA    FRT        QRE
AAA    HRE        HRE
ABA    EEE        EEE
ABA    URE        FRE

如何使用if语句保存到输出文件

file = "/output.csv"
df.to_csv(file, sep="%", index=False)

Answer 1

你可以这样做：

In [121]: df[df['field2']!=df['field3']]
Out[121]: 
    id field2 field3
1  AAA    FSD    FRE
4  AAA    FRT    QRE
7  ABA    URE    FRE

In [122]: df[df['field2']!=df['field3']].to_csv(file, sep="%", index=False)

In [123]: df = df[df['field2']==df['field3']]

In [124]: df
Out[124]: 
    id field2 field3
0  AAA    SRE    SRE
2  AAA    TUE    TUE
3  ABA    SDE    SDE
5  AAA    HRE    HRE
6  ABA    EEE    EEE