熊猫数据框如何根据另一列添加c列

Question

    |  red  | blue  | winner|
    |:------|:-----:|------:|
0   |70.0   |67.0   |Red    |
1   |74.0   |76.0   |Red    |
2   |75.0   |75.0   |Red    |
3   |63.0   |61.0   |Blue   |
4   |68.0   |72.0   |Blue   |

在 Pandas DataFrame 中，只有当红色和蓝色列是获胜者列中显示的获胜者时，我将如何将它们相加。

所以在这个例子中红色 = 70 + 74 + 75 和蓝色 = 61 + 72

Answer 1

import pandas as pd

df = pd.DataFrame(
    data={
        'red' : [70.0, 74.0, 75.0, 63.0, 68.0],
        'blue' : [67.0, 76.0, 75.0, 61.0, 72.0],
        'winner' : ['Red', 'Red', 'Red', 'Blue', 'Blue']
    }
)
print(df['red'][df['winner'] == 'Red'].sum())
print(df['blue'][df['winner'] == 'Blue'].sum())