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(self):
        # a Structure with a POINTER field
        class S(Structure):
            _fields_ = [("array", POINTER(c_int))]

        s = S()
        # We can assign arrays of the correct type
        s.array = (c_int * 3)(1, 2, 3)
        items = [s.array[i] for i in range(3)]
        self.assertEqual(items, [1, 2, 3])

        # The following are bugs, but are included here because the unittests
        # also describe the current behaviour.
        #
        # This fails with SystemError: bad arg to internal function
        # or with IndexError (with a patch I have)

        s.array[0] = 42

        items = [s.array[i] for i in range(3)]
        self.assertEqual(items, [42, 2, 3])

        s.array[0] = 1