Question

对于以下数据框df1：

sentence         A       B     C      D      F       G
 dizzy           1       1     0      0      k       1
 Head            0       0     1      0      l       1
 nausea          0       0     0      1      fd      1
 zap             1       0     1      0      g       1
 dizziness       0       0     0      1      V       1

我需要从列句子创建一个字典，其中包含A，B，C和D列。

在下一步中，我需要将数据帧F2中的句子列映射到值A，B，C和D.输出如下：

   sentences         A       B     C      D            
     dizzy           1       1     0      0
     happy             
     Head            0       0     1      0             
     nausea          0       0     0      1
     fill out           
     zap             1       0     1      0             
     dizziness       0       0     0      1     

  This is my code, but just for one column, I do not know how to do it for several columns:


equiv = df1.set_index (sentences)[A].to_dict()
df2[A]=df2[sentences].apply (lambda x:equiv.get(x, np.nan))

感谢。

Answer 1

IIUC：

设定：

In [164]: df1
Out[164]:
    sentence  A  B  C  D   F  G
0      dizzy  1  1  0  0   k  1
1       Head  0  0  1  0   l  1
2     nausea  0  0  0  1  fd  1
3        zap  1  0  1  0   g  1
4  dizziness  0  0  0  1   V  1

In [165]: df2
Out[165]:
   sentences
0      dizzy
1      happy
2       Head
3     nausea
4   fill out
5        zap
6  dizziness

解决方案：

In [174]: df2[['sentences']].merge(df1[['sentence','A','B','C','D']], 
                                   left_on='sentences',
                                   right_on='sentence', 
                                   how='outer')
Out[174]:
   sentences   sentence    A    B    C    D
0      dizzy      dizzy  1.0  1.0  0.0  0.0
1      happy        NaN  NaN  NaN  NaN  NaN
2       Head       Head  0.0  0.0  1.0  0.0
3     nausea     nausea  0.0  0.0  0.0  1.0
4   fill out        NaN  NaN  NaN  NaN  NaN
5        zap        zap  1.0  0.0  1.0  0.0
6  dizziness  dizziness  0.0  0.0  0.0  1.0

从pandas中的多个列创建字典

1 个答案: