Transpose dataframe in Python pandas

Question

I have a dataframe like this

Input

>>> df

 sent      cite 
 a         1,2,3
 b         2,4
 c         5

I want to transpose the dataframe that each row contains the values of cite and sent combined. Notice that the cite and the sent can be repeated (eg, cite 2 )

Expected Output

>>> df

 cite      sent 
 1         a
 2         a
 2         b
 3         a
 4         b
 5         c

I have tried with this but it did not work

df = df.pivot( columns='cite', values='sent')

Answer 1

Use Series.str.split with df.explode and df.sort_values :

In [141]: df = df.assign(cite=df['cite'].str.split(',')).explode('cite').sort_values('cite')

In [142]: df
Out[142]: 
  sent cite
0    a    1
0    a    2
1    b    2
0    a    3
1    b    4
2    c    5

Answer 2

Try split then explode

df = df.assign(cite=df['cite'].str.split(',')).explode('cite')