我有以下表:
+-----------+------+-------+
| member_id | year | count |
+-----------+------+-------+
| 1 | 2012 | 1 |
| 1 | 2013 | 0 |
| 1 | 2014 | 1 |
| 2 | 2012 | 2 |
| 2 | 2013 | 0 |
| 2 | 2014 | 1 |
+-----------+------+-------+
我想将其变成:
+-----------+------------+------------+------------+
| member_id | count_2012 | count_2013 | count_2014 |
+-----------+------------+------------+------------+
| 1 | 1 | 0 | 1 |
| 2 | 2 | 0 | 1 |
+-----------+------------+------------+------------+
我尝试进行分组,然后旋转,并且只是枢转,但是枢轴需要和绘制,而我不尝试更改值,只需重新设计。
df = df.pivot(index='member_id',columns='year', values='count')
如果您不想将成员_id作为索引:
df = df.pivot(index='member_id',columns='year', values='count').reset_index()