def test_layers_view():
    X = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
    L = np.array([[10, 11, 12], [13, 14, 15], [16, 17, 18]])
    real_adata = ad.AnnData(X)
    real_adata.layers["L"] = L
    view_adata = real_adata[1:, 1:]
    real_hash = joblib.hash(real_adata)
    view_hash = joblib.hash(view_adata)

    assert view_adata.is_view

    with pytest.raises(ValueError):
        view_adata.layers["L2"] = L + 2

    assert view_adata.is_view  # Failing to set layer item makes adata not view
    assert real_hash == joblib.hash(real_adata)
    assert view_hash == joblib.hash(view_adata)

    view_adata.layers["L2"] = L[1:, 1:] + 2

    assert not view_adata.is_view
    assert real_hash == joblib.hash(real_adata)
    assert view_hash != joblib.hash(view_adata)
def test_packed(self):
        class X(Structure):
            _fields_ = [("a", c_byte),
                        ("b", c_longlong)]
            _pack_ = 1

        self.assertEqual(sizeof(X), 9)
        self.assertEqual(X.b.offset, 1)

        class X(Structure):
            _fields_ = [("a", c_byte),
                        ("b", c_longlong)]
            _pack_ = 2
        self.assertEqual(sizeof(X), 10)
        self.assertEqual(X.b.offset, 2)

        class X(Structure):
            _fields_ = [("a", c_byte),
                        ("b", c_longlong)]
            _pack_ = 4
        self.assertEqual(sizeof(X), 12)
        self.assertEqual(X.b.offset, 4)

        import struct
        longlong_size = struct.calcsize("q")
        longlong_align = struct.calcsize("bq") - longlong_size

        class X(Structure):
            _fields_ = [("a", c_byte),
                        ("b", c_longlong)]
            _pack_ = 8

        self.assertEqual(sizeof(X), longlong_align + longlong_size)
        self.assertEqual(X.b.offset, min(8, longlong_align))


        d = {"_fields_": [("a", "b"),
                          ("b", "q")],
             "_pack_": -1}
        self.assertRaises(ValueError, type(Structure), "X", (Structure,), d)

        # Issue 15989
        d = {"_fields_": [("a", c_byte)],
             "_pack_": _testcapi.INT_MAX + 1}
        self.assertRaises(ValueError, type(Structure), "X", (Structure,), d)
        d = {"_fields_": [("a", c_byte)],
             "_pack_": _testcapi.UINT_MAX + 2}
        self.assertRaises(ValueError, type(Structure), "X", (Structure,), d)