python - 两个值匹配 pandas 时的累积计数

Question

我正在尝试创建一个新的 Column显示 cumulative count基于单独的值 columns 。

因此，对于下面的代码，我尝试根据 Cause 创建两个新列和Answer Columns 。因此对于 Column Answer 中的值，如果In位于Column Cause我想在新列中提供累积计数。

import pandas as pd

d = ({
    'Cause' : ['In','','','In','','In','In'],
    'Answer' : ['Yes','No','Maybe','No','Yes','No','Yes'],
    })

df = pd.DataFrame(d)

输出:

  Answer Cause
0    Yes    In
1     No      
2  Maybe      
3     No    In
4    Yes      
5     No    In
6    Yes    In

预期输出:

  Answer Cause Count_No Count_Yes
0    Yes    In                  1
1     No                         
2  Maybe                         
3     No    In        1          
4    Yes                         
5     No    In        2          
6    Yes    In                  2

我已尝试以下操作，但出现错误。

df['cumsum'] = df.groupby(['Answer'])['Cause'].cumsum()

Answer 1

这是一种方法 -

for val in ['Yes', 'No']:
    cond = df.Answer.eq(val) & df.Cause.eq('In')
    df.loc[cond, 'Count_' + val] = cond[cond].cumsum()

df
#  Cause Answer  Count_Yes  Count_No
#0    In    Yes        1.0       NaN
#1           No        NaN       NaN
#2        Maybe        NaN       NaN
#3    In     No        NaN       1.0
#4          Yes        NaN       NaN
#5    In     No        NaN       2.0
#6    In    Yes        2.0       NaN