Pandas modify value after first N True value-CodePudding

I have the following to tables of boolean values:

df1 = pd.DataFrame(data={'v': [True, True, True],
                         'w': [True, False, False], 
                         'x': [False, True, False],
                         'y': [True, True, True],
                         'z': [True, False, True]},
                         index=pd.Series([1, 2, 3], name='index'))

index	v	w	x	y	z
1	True	True	False	True	True
2	True	False	True	True	False
3	True	False	False	True	True

After n first True values in each row, how can I turn rest of the values into False? For example, if n was 2:

index	v	w	x	y	z
1	True	True	False	False	False
2	True	False	True	False	False
3	True	False	False	True	False

Row row 1, x and y would turn to False, since v and w are True.

CodePudding user response：

Try with where and cumsum

n = 2
out = df1.where(df1.cumsum(axis=1)<=n,False)
Out[24]: 
          v      w      x      y      z
index                                  
1      True   True  False  False  False
2      True  False   True  False  False
3      True  False  False   True  False