def test_drop_obs_column():
    adata = ad.AnnData(np.array(X_list), obs=obs_dict, dtype="int32")

    subset = adata[:2]
    assert subset.is_view
    # returns a copy of obs
    assert subset.obs.drop(columns=["oanno1"]).columns.tolist() == ["oanno2", "oanno3"]
    assert subset.is_view
    # would modify obs, so it should actualize subset and not modify adata
    subset.obs.drop(columns=["oanno1"], inplace=True)
    assert not subset.is_view
    assert subset.obs.columns.tolist() == ["oanno2", "oanno3"]

    assert adata.obs.columns.tolist() == ["oanno1", "oanno2", "oanno3"]
def test_subclass_delayed(self):
        class X(Structure):
            pass
        self.assertEqual(sizeof(X), 0)
        X._fields_ = [("a", c_int)]

        class Y(X):
            pass
        self.assertEqual(sizeof(Y), sizeof(X))
        Y._fields_ = [("b", c_int)]

        class Z(X):
            pass

        self.assertEqual(sizeof(X), sizeof(c_int))
        self.assertEqual(sizeof(Y), sizeof(c_int)*2)
        self.assertEqual(sizeof(Z), sizeof(c_int))
        self.assertEqual(X._fields_, [("a", c_int)])
        self.assertEqual(Y._fields_, [("b", c_int)])
        self.assertEqual(Z._fields_, [("a", c_int)])