python - Pandas dataframe select rows where a list-column contains any of a list of strings

Question

I've got a pandas DataFrame that looks like this:

  molecule            species
0        a              [dog]
1        b       [horse, pig]
2        c         [cat, dog]
3        d  [cat, horse, pig]
4        e     [chicken, pig]

and I like to extract a DataFrame containing only thoses rows, that contain any of selection = ['cat', 'dog']. So the result should look like this:

  molecule            species
0        a              [dog]
1        c         [cat, dog]
2        d  [cat, horse, pig]

What would be the simplest way to do this?

For testing:

selection = ['cat', 'dog']
df = pd.DataFrame({'molecule': ['a','b','c','d','e'], 'species' : [['dog'], ['horse','pig'],['cat', 'dog'], ['cat','horse','pig'], ['chicken','pig']]})

Answer 1

IIUC Re-create your df then using isin with any should be faster than apply

df[pd.DataFrame(df.species.tolist()).isin(selection).any(1).values]
Out[64]: 
  molecule            species
0        a              [dog]
2        c         [cat, dog]
3        d  [cat, horse, pig]