有效合并熊猫中的子序列

Question

I have predictions from the ML model in the form of pandas Series (binary only). For example: pd.Series([0,0,0,1,1,0,0,1,0,1]) .

I want to merge subsequences of 1's if the number of 0's between them is less than some threshold. For example, if the threshold is 1, I want to get the following series instead: pd.Series([0,0,0,1,1,0,0,1,1,1]) .

If the threshold is 2: pd.Series([0,1,0,1,0,0,1,0,0,1,0,0,0,0,1,0]) -> pd.Series([0,1,1,1,1,1,1,1,1,1,0,0,0,0,1,0]) .

Of course, it is possible to do it just iterating the Series row-by-row, but I was wondering if there is an efficient way of doing it by using some pandas methods?

Answer 1

Seems like you need

v=s.loc[s.idxmax():s.iloc[::-1].idxmax()] # we need exclude the bottom 0 and head 0
s1=v.eq(1).cumsum()# create the key 
s1=v.mask(s1.groupby(s1).transform('max')<=2,1) # setting up the max count number 
s.update(s1) #using update to update origin series 
s
0     0
1     1
2     1
3     1
4     1
5     1
6     1
7     0
8     0
9     1
10    0
11    0
12    0
13    0
14    1
15    0
dtype: int64