根据值将列转换为多列

Question

在Python中,我想知道是否有办法从这里转换单列数据帧:

进入这个:

Answer 1

来源DF:

In [204]: df
Out[204]:
     Country
0      Italy
1  Indonesia
2     Canada
3      Italy

我们可以使用pd.get_dummies():

In [205]: pd.get_dummies(df.Country)
Out[205]:
   Canada  Indonesia  Italy
0       0          0      1
1       0          1      0
2       1          0      0
3       0          0      1

或者sklearn.feature_extraction.text.CountVectorizer:

In [211]: from sklearn.feature_extraction.text import CountVectorizer

In [212]: cv = CountVectorizer()

In [213]: r = pd.SparseDataFrame(cv.fit_transform(df.Country), 
                                 columns=cv.get_feature_names(), 
                                 index=df.index,
                                 default_fill_value=0)

In [214]: r
Out[214]:
   canada  indonesia  italy
0       0          0      1
1       0          1      0
2       1          0      0
3       0          0      1