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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def read(self, *pk):
 """ Return a list of entries in the table or single entry if there is an pk. .. code-block:: python # All users DBSession.sacrud(Users).read() # Composite primary_key DBSession.sacrud(User2Groups).read({'user_id': 4, 'group_id': 2}) # Multiple rows primary_keys = [ {'user_id': 4, 'group_id': 2}, {'user_id': 4, 'group_id': 3}, {'user_id': 1, 'group_id': 1}, {'user_id': 19, 'group_id': 2} ] DBSession.sacrud(User2Groups).read(*primary_keys) # JSON using primary_keys = '''[ {"user_id": 4, "group_id": 2}, {"user_id": 4, "group_id": 3}, {"user_id": 1, "group_id": 1}, {"user_id": 19, "group_id": 2} ]''' DBSession.sacrud(User2Groups).read(primary_keys) # Delete DBSession.sacrud(User2Groups).read(*primary_keys)\ .delete(synchronize_session=False) # Same, but work with only not composite primary key DBSession.sacrud(Users).read((5, 10)) # as list DBSession.sacrud(Users).read('[5, 10]') # as JSON DBSession.sacrud(Users).read('{"id": 5}') # as JSON explicit pk DBSession.sacrud(Users).read(5, "1", 2) # as *args DBSession.sacrud(Users).read(42) # single """

        pk = [unjson(obj) for obj in pk]

        if len(pk) == 1:  # like ([1,2,3,4,5], )
            return get_obj(self.session, self.table, pk[0])
        elif len(pk) > 1:  # like (1, 2, 3, 4, 5)
            return get_obj(self.session, self.table, pk)
        return self.session.query(self.table)