python - Pandas DataFrame slicing based on logical conditions? -


i have dataframe called data:

       subjects  professor  studentid 8     chemistry       jane        999 1     chemistry       jane       3455 0     chemistry     joseph       1234 2       history       jane       3455 6       history      smith        323 7       history      smith        999 3   mathematics        doe      56767 10  mathematics   einstein       3455 5       physics   einstein       2834 9       physics      smith        323 4       physics      smith        999

i want run query "professors @ least 2 classes 2 or more of same students". desired output

smith: physics, history, 323, 999

i familiar sql , have done easily, still beginner in python. how achieve output in python? line of thought convert dataframe sql database , have sql interface through python run queries. there way accomplish that?

students_and_subjects = df.groupby(                                ['professor', 'subjects']                            ).studentid.nunique().ge(2) \                           .groupby(level='professor').sum().ge(2)  df[df.professor.map(students_and_subjects)]

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