如何转置数据框

Question

我的数据框看起来像这样 -

      project name       comment1     comment2           comment3      comment4
Row1           NY       Not good    somewhat ok         ridiculous  satisfactory
Row2           LA   job well done     standard   under performance      standard

如何将其转换为如下所示？

     project name            comment
Row1           NY           Not good
Row2           NY        Somewhat Ok
Row3           NY         ridiculous
Row4           NY       satisfactory
Row5           LA      job well done
Row6           LA           standard
Row7           LA  under performance
Row8           LA           standard

这是一个转置操作，但只有comment1到comment4被转置。在SAS中，可以创建阵列。但我不知道如何在python中解决问题。有没有人这样做过？

Answer 1

您需要melt：

df.melt(id_vars='project name', value_name='comment').drop('variable', axis=1)\
  .sort_values(by='project name')

输出：

  project name            comment
1           LA      job well done
3           LA           standard
5           LA  under performance
7           LA           standard
0           NY           Not good
2           NY        somewhat ok
4           NY         ridiculous
6           NY       satisfactory