我有两列要使用同一字典映射到一个新列(如果字典中没有匹配的键，则返回0)。
>> codes = {'2':1,
'31':1,
'88':9,
'99':9}
>> df[['driver_action1','driver_action2']].to_dict()
{'driver_action1': {0: '1',
1: '1',
2: '77',
3: '77',
4: '1',
5: '4',
6: '2',
7: '1',
8: '77',
9: '99'},
'driver_action2': {0: '31',
1: '99',
2: '31',
3: '55',
4: '1',
5: '5',
6: '99',
7: '2',
8: '4',
9: '99'}}
我以为我可以做:
>> df['driver_reckless_remapped'] = df[['driver_action1','driver_action2']].applymap(lambda x: codes.get(x,0))
预期产量:
driver_action1 driver_action2 driver_reckless_remapped
0 1 31 1
1 1 99 9
2 77 31 1
3 77 55 0
4 1 1 0
5 4 5 0
6 2 99 1
7 1 2 1
8 77 4 0
9 99 99 9
但是我得到了:
TypeError: ("'dict' object is not callable", 'occurred at index driver_action1')
有没有办法将多列映射到一个新列？
最佳答案
IIUC可以使用combine_first()方法
df['new'] = = \
df.driver_action1.map(codes).combine_first(df.driver_action2.map(codes)).fillna(0)
查看:
In [106]: df['new'] = df.driver_action1.map(codes).combine_first(df.driver_action2.map(codes)).fillna(0)
In [107]: df
Out[107]:
driver_action1 driver_action2 driver_reckless_remapped new
0 1 31 1 1.0
1 1 99 9 9.0
2 77 31 1 1.0
3 77 55 0 0.0
4 1 1 0 0.0
5 4 5 0 0.0
6 2 99 1 1.0
7 1 2 1 1.0
8 77 4 0 0.0
9 99 99 9 9.0
关于python - Pandas :将多列映射到一列，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/43543634/