python pandas: how to find rows in one dataframe but not in another?

Question

Let\'s say that I have two tables: people_all and people_usa, both with the same structure and therefore the same primary key.

How can I g

Answer 1

Here is another similar to SQL Pandas method: .query():

people_all.query('ID not in @people_usa.ID')

or using NumPy's in1d() method:

people_all.[~np.in1d(people_all, people_usa)]

NOTE: for those who have experience with SQL it might be worth to read Pandas comparison with SQL