Concatenate two columns containing lists python

Question

How do I concatenate two columns having lists such that there are no duplicates in the resultant list.

df:

A         B  

[a,b]   [c,d,a,b]
[s,d]   [d,f]

Expected Result in new column:

A_B
[a,b,c,d]
[s,d,f]

Whenever you say something like "no duplicates in list" what you actually mean is that you want a set — Harshal Parekh, Jul 31 '19 at 21:59

piRSquared · Accepted Answer · 2019-07-31T22:10:02.567

2

Crude but succint

df.sum(1).map(set).map(list).to_frame('_'.join(df))

            A_B
0  [a, d, b, c]
1     [s, d, f]

Less crude and less succint

But probably better

pd.DataFrame(
    {'_'.join(df): [[*set().union(*t)] for t in zip(*map(df.get, df))]},
    df.index,
)

            A_B
0  [a, d, b, c]
1     [s, d, f]

Setup

df = pd.DataFrame(dict(A=[[*'ab'], [*'sd']], B=[[*'cdab'], [*'df']]))

edited Jul 31 '19 at 22:10

answered Jul 31 '19 at 21:57

piRSquared

285,575
57
475
624

The resultant column should not have duplicates. – Harshal Parekh Jul 31 '19 at 21:58
@ScottBoston thanks. Will correct. – piRSquared Jul 31 '19 at 21:59
Oh.. that -1 wasn't me. :) – Scott Boston Jul 31 '19 at 22:00
Oh I figured it wasn't (-: No worries. – piRSquared Jul 31 '19 at 22:01

Concatenate two columns containing lists python

1 Answers1

Crude but succint

Less crude and less succint

Setup