def __getitem__(self, key):
        """ Returns column's value. """
        if not isinstance(key, six.string_types):
            raise TypeError
        if self._columns.keys() not in key:
            raise KeyError
        return getattr(self, key)
dataset/ETHPy150Open datastax/python-driver/cassandra/cqlengine/models.py/BaseModel.__getitem__/swapped operands of `not in`