DataFrame分组依据上的 pandas 百分比计数 [英] Pandas Percentage count on a DataFrame groupby

问题描述

我有一个DataFrame(mydf)，如下所示:

I have a DataFrame (mydf) along the lines of the following:

Index   Feature ID  Stuff1  Stuff2
1       True    1   23      12
2       True    1   54      12
3       False   0   45      67
4       True    0   38      29
5       False   1   32      24
6       False   1   59      39
7       True    0   37      32
8       False   0   76      65
9       False   1   32      12
10      True    0   23      15
..n     True    1   21      99

我正在尝试为每个ID(0或1)计算Feature的正确和错误百分比，并且我正在为每个ID寻找两个输出:

I am trying to calculate the True and False percentages of the Feature for each ID (0 or 1), and I am looking for two output for each ID:

Feature ID  Percent
True    1   20%
False   1   30%

Feature ID  Percent
True    0   30%
False   0   20%

我尝试了一些尝试，但是我开始获得所有列的计数，然后获得所有列的百分比.

I have tried a few attempts, but I start getting counts for all columns and then a percentage for all columns.

这是我的错误尝试:

percentageID0 = mydf[ mydf['ID']==0 ].set_index(['Feature']).count()
percentageID1 = mydf[ mydf['ID']==1 ].set_index(['Feature']).count()
fullcount = (mydf.groupby(['ID']).count()).sum()

print (percentageID0/fullcount) * 100
print (percentageID1/fullcount) * 100

认为我对groupby/index格式感到困惑.

Think I am getting mixed up with the groupby/index format.

推荐答案

可能就是这样:

In [73]:

print pd.DataFrame({'Percentage': df.groupby(('ID', 'Feature')).size() / len(df)})
            Percentage
ID Feature            
0  False           0.2
   True            0.3
1  False           0.3
   True            0.2

这篇关于DataFrame分组依据上的 pandas 百分比计数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！