Explode lists with different lengths in Pandas

Question

I've got a pandas dataframe in which one of the columns contains lists with different lengths. The solutions to explode lists in pandas all assume that the lists to be exploded are all the same length.

This is my df:

    Dep     Exp     Fl-No   Shared Codes
0   20:58   20:55   LX 736  [No shared codes]
1   21:23   20:55   LX 818  [Dummy, LH 5809]
2   21:27   21:00   JU 375  [No shared codes]
4   21:28   21:00   LX 770  [Dummy, SN 5102]
7   21:31   21:10   LX 1842 [Dummy, LH 5880, TP 8184, A3 1985]

And this what I am looking for:

    Dep     Exp     Fl-No   Shared Codes
0   20:58   20:55   LX 736  No shared codes
1   21:23   20:55   LX 818  Dummy
1   21:23   20:55   LX 818  LH 5809
2   21:27   21:00   JU 375  No shared codes
4   21:28   21:00   LX 770  Dummy
4   21:28   21:00   LX 770  SN 5102
7   21:31   21:10   LX 1842 Dummy
7   21:31   21:10   LX 1842 LH 5880
7   21:31   21:10   LX 1842 TP 8184
7   21:31   21:10   LX 1842 A3 1985

Has anybody got any suggestions?

Answer 1

Very similar to @coldspeed. I took a few different steps.

s = df['Shared Codes']
i = np.arange(len(df)).repeat(s.str.len())
df.iloc[i, :-1].assign(**{'Shared Codes': np.concatenate(s.values)})

     Dep    Exp    Fl-No     Shared Codes
0  20:58  20:55   LX 736  No shared codes
1  21:23  20:55   LX 818            Dummy
1  21:23  20:55   LX 818          LH 5809
2  21:27  21:00   JU 375  No shared codes
4  21:28  21:00   LX 770            Dummy
4  21:28  21:00   LX 770          SN 5102
7  21:31  21:10  LX 1842            Dummy
7  21:31  21:10  LX 1842          LH 5880
7  21:31  21:10  LX 1842          TP 8184
7  21:31  21:10  LX 1842          A3 1985

Answer 2

One possibility using np.repeat and np.hstack:

print(df)

     Dep    Exp    Fl-No                        Shared Codes
0  20:58  20:55   LX 736                   [No shared codes]
1  21:23  20:55   LX 818                    [Dummy, LH 5809]
2  21:27  21:00   JU 375                   [No shared codes]
4  21:28  21:00   LX 770                    [Dummy, SN 5102]
7  21:31  21:10  LX 1842  [Dummy, LH 5880, TP 8184, A3 1985]


x = df.iloc[:, :-1].values.repeat(df['Shared Codes'].apply(len), 0)
y = df['Shared Codes'].apply(pd.Series).stack().values.reshape(-1, 1)

out = pd.DataFrame(np.hstack((x, y)), columns=df.columns)
print(out)

     Dep    Exp    Fl-No     Shared Codes
0  20:58  20:55   LX 736  No shared codes
1  21:23  20:55   LX 818            Dummy
2  21:23  20:55   LX 818          LH 5809
3  21:27  21:00   JU 375  No shared codes
4  21:28  21:00   LX 770            Dummy
5  21:28  21:00   LX 770          SN 5102
6  21:31  21:10  LX 1842            Dummy
7  21:31  21:10  LX 1842          LH 5880
8  21:31  21:10  LX 1842          TP 8184
9  21:31  21:10  LX 1842          A3 1985