split a column into multiple lists, and keep deliminator

Question

I have a dataframe, which I need to split a column on character "Y" and keep this deliminator. For example,

    import pandas as pd

    d1 = pd.DataFrame({'user': [1,2,3],'action': ['YNY','NN','NYYN']})

The output dataframe should look like this,

    d2 = pd.DataFrame([{'action': 'Y, NY', 'user': 1},
           {'action': 'NN', 'user': 2},
          {'action': 'NY, Y, N', 'user': 3}])

    in[1]: d1
    out[1]: action  user
            YNY         1
            NN          2
            NYYN        3

    in[2]: d2
    out[2]:  action user
            Y,NY        1
            NN          2
            NY,Y, N     3

I have tried a few questions such as Python split() without removing the delimiter and Python splitting on regex without removing delimiters. But they are not exactly what I am looking for here.

Is it ok if the last row reads "N, Y, YN"? If not, would you be okay if the first row was YN, Y? — cs95, Jan 04 '19 at 20:10

score 1 · Answer 1 · answered Jan 04 '19 at 20:18

1

Sounds like you need

d1.action.str.split('([^Y]*Y)').map(lambda x : [z for z in x  if z!= ''])
Out[234]: 
0       [Y, NY]
1          [NN]
2    [NY, Y, N]
Name: action, dtype: object

answered Jan 04 '19 at 20:18

BENY

317,841
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234

score 1 · Answer 2 · answered Jan 04 '19 at 20:25

1

Use -

d1['action'].str.split('Y').str.join('Y,').str.rstrip(',')

Output

0      Y,NY
1        NN
2    NY,Y,N

answered Jan 04 '19 at 20:25

Vivek Kalyanarangan

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split a column into multiple lists, and keep deliminator

2 Answers2