Python 数据帧使用列作为行（熔化）

我知道，这个问题已经被问过好几次了，但我没有根据已经问过的问题来构建我的解决方案

DF我有：

id| country  |  series name   | 2015 | 2016 | 2017
--+----------+----------------+------+------+------
0 | saudi    | fertility rate | 1    | 2    | 2   |    
1 | saudi    | CO2 emissions  | 5    | 10   | 15  | 
2 | pakistan | fertility rate | 1    | 2    | 1   |
3 | pakistan | CO2 emissions  | NaN  | NaN  | NaN |

id| country  | year | fertility rate | CO2 emissions 
--+----------+------+----------------+---------
0 | saudi    | 2015 |       1        |    5      
1 | saudi    | 2016 |       2        |    10      
2 | saudi    | 2017 |       2        |    15      
3 | pakistan | 2015 |       1        |    NaN
4 | pakistan | 2016 |       2        |    NaN
5 | pakistan | 2017 |       1        |    NaN

DF我想要：

id| country  |  series name   | 2015 | 2016 | 2017
--+----------+----------------+------+------+------
0 | saudi    | fertility rate | 1    | 2    | 2   |    
1 | saudi    | CO2 emissions  | 5    | 10   | 15  | 
2 | pakistan | fertility rate | 1    | 2    | 1   |
3 | pakistan | CO2 emissions  | NaN  | NaN  | NaN |

id| country  | year | fertility rate | CO2 emissions 
--+----------+------+----------------+---------
0 | saudi    | 2015 |       1        |    5      
1 | saudi    | 2016 |       2        |    10      
2 | saudi    | 2017 |       2        |    15      
3 | pakistan | 2015 |       1        |    NaN
4 | pakistan | 2016 |       2        |    NaN
5 | pakistan | 2017 |       1        |    NaN

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我尝试了多种不同的熔体配置，但不知何故，我无法解决这个问题

IIUC

melt

+

pivot\u表

。这个答案假设

id

是您的索引。如果不是，就把它放下，因为计算中不需要它

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您能使数据源易于复制吗？