pandas groupby column to list and keep certain values

I have the following dataframe:

id       occupations
111      teacher
111      student
222      analyst
333      cook
111      driver
444      lawyer

I create a new column with a list of the all the occupations:

new_df['occupation_list'] = df['id'].map(df.groupby('id')['occupations'].agg(list))

How do I only include teacher and student values in occupation_list?

Answer

You can filter before groupby:

to_map = (df[df['occupations'].isin(['teacher', 'student'])]
             .groupby('id')['occupations'].agg(list)
         )

df['occupation_list'] = df['id'].map(to_map)

Output:

    id occupations     occupation_list
0  111     teacher  [teacher, student]
1  111     student  [teacher, student]
2  222     analyst                 NaN
3  333        cook                 NaN
4  111      driver  [teacher, student]
5  444      lawyer                 NaN