熊猫中多索引的百分比

Question

我需要找到MultiIndex列的百分比（“计数”）。我的DataFrame看起来像：

            count
A  week1     264

   week2      29

B  week1     152

   week2      15

我想添加一列“百分比”

            count percent
A  week1     264      0.9

   week2      29      0.1

B  week1     152     0.91

   week2      15     0.09

我知道我可以找到想要的总数

mydf.sum(level=[0, 1])

但我似乎无法弄清楚如何将其转换为百分比。

Answer 1

您可以使用groupby和完成此操作transform：

df['percent'] = df.groupby(level=0).transform(lambda x: (x / x.sum()).round(2))

#          count  percent
# A week1    264     0.90
#   week2     29     0.10
# B week1    152     0.91
#   week2     15     0.09

Answer 2

没有groupby

df['percentage']=df['count'].div(df['count'].sum(level=0),level=0)
df
Out[128]: 
         count  percentage
x b                       
A week1    264    0.901024
  week2     29    0.098976
B week1    152    0.910180
  week2     15    0.089820