I would like to change the following dataframe:
--id--rating--timestamp--
-------------------------
| 0 | 5.0 | 231312231 |
| 1 | 3.0 | 192312311 | #Epoch time (seconds from 1 Thursday, 1 January 1970)
-------------------------
转换为以下数据框:
--id--rating--timestamp--
--------------------------
| 0 | 5.0 | 05 |
| 1 | 3.0 | 04 | #Month of year
--------------------------
我该怎么做?