def test_views():
    X = np.array(X_list)
    adata = ad.AnnData(X, obs=obs_dict, var=var_dict, uns=uns_dict, dtype="int32")

    assert adata[:, 0].is_view
    assert adata[:, 0].X.tolist() == np.reshape([1, 4, 7], (3, 1)).tolist()

    adata[:2, 0].X = [0, 0]

    assert adata[:, 0].X.tolist() == np.reshape([0, 0, 7], (3, 1)).tolist()

    adata_subset = adata[:2, [0, 1]]

    assert adata_subset.is_view
    # now transition to actual object
    adata_subset.obs["foo"] = range(2)
    assert not adata_subset.is_view

    assert adata_subset.obs["foo"].tolist() == list(range(2))
def intersectmatchers(m1, m2):
    """Composes two matchers by matching if both of them match.

    The second matcher's non-matching-attributes (root, cwd, bad, traversedir)
    are ignored.
    """
    if m1 is None or m2 is None:
        return m1 or m2
    if m1.always():
        m = copy.copy(m2)
        # TODO: Consider encapsulating these things in a class so there's only
        # one thing to copy from m1.
        m.bad = m1.bad
        m.traversedir = m1.traversedir
        m.abs = m1.abs
        m.rel = m1.rel
        m._relativeuipath |= m1._relativeuipath
        return m
    if m2.always():
        m = copy.copy(m1)
        m._relativeuipath |= m2._relativeuipath
        return m
    return intersectionmatcher(m1, m2)