如何将具有 n 个值的 DataFrame 列转换为 n 个二进制列？

Question

I am prety sure that there is a pandas function to do so but I could not find it when I was looking at the documentation and googled it. Maybe you can help me. Here is what I want to do:

import pandas as pd

data = {'col1': ['val1','val2','val3'],
        'col2': ['feat1','feat1','feat2']
       }
df = pd.DataFrame(data)
print (df)

>    col1   col2
> 0  val1  feat1
> 1  val2  feat1
> 2  val3  feat2

and I want to have the dataframe with this shape:

>    col1  feat1  feat2
> 0  val1      1      0
> 1  val2      1      0
> 2  val3      0      1

Best P

Answer 1

print(pd.get_dummies(df.set_index('col1'), prefix='', prefix_sep=''))

Prints:

      feat1  feat2
col1              
val1      1      0
val2      1      0
val3      0      1

Answer 2

您也可以使用crosstab

pd.crosstab(df.col1, df.col2)