Count unique values using pandas groupby

Question

I have data of the following form:

df = pd.DataFrame({
    \'group\': [1, 1, 2, 3, 3, 3, 4],
    \'param\': [\'a\', \'a\', \'b\', np.nan, \'a\', \'a\', np.na         


        

Answer 1

I know it has been a while since this was posted, but I think this will help too. I wanted to count unique values and filter the groups by number of these unique values, this is how I did it:

df.groupby('group').agg(['min','max','count','nunique']).reset_index(drop=False)