Extract string from one column to new column – Pandas

Question

I have a column that I need to extract and separate all the genres, then add those extract genres back into dataframe. I tried to implement str.extract() method but don't get anywhere.

Column example:

|title||genres|
|-----||------|
|Cowboy Bebop||['Comedy', 'Dementia', 'Horror', 'Seinen']|

Ideal new column:

|title||genres|
|-----||------|
|Cowboy Bebop||'Comedy'|
|CowBoy Bebop||'Dementia'|
|CowBoy Bebop||'Horror'|
|CowBoy Bebop||'Seinen'|

Answer 1

You need pandas.DataFrame.explode:

df = df.explode('genres').reset_index(drop=True)

Output:

>>> df
          title    genres
0  Cowboy Bebop    Comedy
1  Cowboy Bebop  Dementia
2  Cowboy Bebop    Horror
3  Cowboy Bebop    Seinen

Note that you might need to convert the values in the genres column to actual list, because it might just look like a list but actually be a string. If so, run this before the above:

import ast
df['genres'] = df['genres'].apply(ast.literal_eval)

Answer 2

This will give you the desired results with .explode()

data = {'title' : ['Cowboy Bebop'], 'genres' : [['Comedy', 'Dementia', 'Horror', 'Seinen']]} 
df = pd.DataFrame(data)
df = df.explode('genres')
df