Python - Unnest cells in Pandas DataFrame

Question

Suppose I have DataFrame df:

a b c
v f 3|4|5
v 2 6
v f 4|5

I\'d like to produce this df:

<         


        

Answer 1

Option 1

In [3404]: (df.set_index(['a', 'b'])['c']
              .str.split('|', expand=True).stack()
              .reset_index(name='c').drop('level_2', 1))
Out[3404]:
   a  b  c
0  v  f  3
1  v  f  4
2  v  f  5
3  v  2  6
4  v  f  4
5  v  f  5

---

Option 2 Using repeat and loc

In [3503]: s = df.c.str.split('|')

In [3504]: df.loc[df.index.repeat(s.str.len())].assign(c=np.concatenate(s))
Out[3504]:
   a  b  c
0  v  f  3
0  v  f  4
0  v  f  5
1  v  2  6
2  v  f  4
2  v  f  5

---

Details

In [3505]: s
Out[3505]:
0    [3, 4, 5]
1          [6]
2       [4, 5]
Name: c, dtype: object