0

我想按id_, Code, Timestamp（因为时间顺序很重要）对值进行排序，然后d1使用id_and对值进行分组，然后对每个组、列和onlyCode使用前向填充，同时保持其他列不变，并返回完整的表。ffillNaN V1V2

d1：


    Type_x  id_             Timestamp               V1   Code Type_y    V2
0   abcd    39-38-30-34     2012-09-20 23:46:05.870 35.5    2    NaN    0
1   abcd    39-38-30-34     2012-09-20 23:46:23.870 44.5    0    NaN    1
2   abcd    39-38-30-34     2012-09-20 23:48:07.870 43.5    0    NaN    1
3   abcd    39-38-30-34     2012-09-20 23:49:48.870 42.5    0    NaN    NaN
4   abcd    39-38-30-34     2012-09-20 23:50:44.870 34.5    2    NaN    NaN

试过：

d2 = d1.sort_values(by = ['id_', 'Code', 'Timestamp']).groupby(['id_', 'Code'])['V1', 'V2'].ffill()

仅返回两列：

        V1      V2
69659   21.5    NaN
300886  21.5    1.0
300887  21.5    0.0
70086   23.0    0.0
300955  23.0    1.0

我应该如何正确地做到这一点？

4

2 回答 2

1

你需要什么退货？

d2 = d1.sort_values(by = ['id_', 'Code', 'Timestamp']).groupby(['id_', 'Code']).ffill()

    

             Type_x     Timestamp    V1  Type_y   V2
1 abcd   39-38-30-34  23:46:23.870  44.5     NaN  1.0
2 abcd   39-38-30-34  23:48:07.870  43.5     NaN  1.0
3 abcd   39-38-30-34  23:49:48.870  42.5     NaN  1.0
0 abcd   39-38-30-34  23:46:05.870  35.5     NaN  0.0
4 abcd  39-38-30-34-  23:50:44.870  34.5     NaN  0.0

或者

d2 = d1.sort_values(by = ['id_', 'Code', 'Timestamp']).groupby(['id_', 'Code']).ffill().dropna(1)
print(d2)

 

             Type_x     Timestamp    V1   V2
1 abcd   39-38-30-34  23:46:23.870  44.5  1.0
2 abcd   39-38-30-34  23:48:07.870  43.5  1.0
3 abcd   39-38-30-34  23:49:48.870  42.5  1.0
0 abcd   39-38-30-34  23:46:05.870  35.5  0.0
4 abcd  39-38-30-34-  23:50:44.870  34.5  0.0
于 2020-10-13T03:56:38.690 回答
1

transform如果您的实际数据框中有其他列而不是您想要groupby的列和您想要的列，您可以逐列使用并执行此操作ffill：

d2 = d1.sort_values(by = ['id_', 'Code', 'Timestamp'])
d2['V1'] = d2.groupby(['id_', 'Code'])['V1'].transform(lambda x: x.ffill())
d2['V2'] = d2.groupby(['id_', 'Code'])['V2'].transform(lambda x: x.ffill())
d2
Out[1]: 
  Type_x          id_                Timestamp    V1  Code  Type_y   V2
1  abcd   39-38-30-34  2012-09-20 23:46:23.870  44.5  0    NaN      1.0
2  abcd   39-38-30-34  2012-09-20 23:48:07.870  43.5  0    NaN      1.0
3  abcd   39-38-30-34  2012-09-20 23:49:48.870  42.5  0    NaN      1.0
0  abcd   39-38-30-34  2012-09-20 23:46:05.870  35.5  2    NaN      0.0
4  abcd   39-38-30-34  2012-09-20 23:50:44.870  34.5  2    NaN      0.0
于 2020-10-13T04:01:45.827 回答