python pandas "groupby" and "if any" condition

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Chapters
00:00 Question
00:53 Accepted answer (Score 2)
01:13 Answer 2 (Score 2)
01:31 Thank you

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Full question
https://stackoverflow.com/questions/7036...

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Tags
#python #pandas

#avk47

ACCEPTED ANSWER

Score 4

You could try the following:

df['new_col'] = df.groupby('project')['sector'].transform(lambda x: (x == 'a').any() )

This will group by project and check if any 'a' is in the groups sectors

ANSWER 2

Score 2

It's not the fastest option, but definitely should work.

new_col = your_db.groupby(['project'])['sector'].unique().apply(lambda x: 'a' in x).rename('new_col')
your_db = your_db.merge(new_col, how = 'inner', left_on = 'project', right_on = 'project')