How to split dataframe cells containing lists into columns?

Question

I have this dataframe

	A	B
0	'a'	['d1','d2']
1	'b'	['e1,'e2','e3']

So column A contains strings, column B contains lists (or when I look for type(): pandas.core.series.series) That I want to look like:

	A	B	B	B
0	'a'	'd1'	'd2'
1	'b'	'e1	'e2'	'e3'

I know how to split strings according to a spliting char with df['B'].str.split('', , expand=True) but I would like to keep working with lists and not have to convert them to strings first.

I did not find a way to do this, or at least did not managed to modify the found code lines to make it work...

# MWE, the example DataFrame
d = ['d1','d2']; e = ['e1','e2','e3']
df = pd.DataFrame({'A': ['a','b'],'B': [d,e]})
print(type(df[df['A'] == 'a']['B']))
print(df)

Thanks.

user_16733101 · Answer

You can try this:

val = df['B'].apply(len).max()
cols = ['B'+str(i) if i != 0 else 'B' for i in range(val)]
df[cols] = df['B'].apply(pd.Series).fillna('')

How to split dataframe cells containing lists into columns?

1 Answers