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 _rootsanddirs(kindpats):
    """Returns roots and exact directories from patterns.

    roots are directories to match recursively, whereas exact directories should
    be matched non-recursively. The returned (roots, dirs) tuple will also
    include directories that need to be implicitly considered as either, such as
    parent directories.

    >>> _rootsanddirs(
    ...     [(b'glob', b'g/h/*', b''), (b'glob', b'g/h', b''),
    ...      (b'glob', b'g*', b'')])
    (['g/h', 'g/h', ''], ['', 'g'])
    >>> _rootsanddirs(
    ...     [(b'rootfilesin', b'g/h', b''), (b'rootfilesin', b'', b'')])
    ([], ['g/h', '', '', 'g'])
    >>> _rootsanddirs(
    ...     [(b'relpath', b'r', b''), (b'path', b'p/p', b''),
    ...      (b'path', b'', b'')])
    (['r', 'p/p', ''], ['', 'p'])
    >>> _rootsanddirs(
    ...     [(b'relglob', b'rg*', b''), (b're', b're/', b''),
    ...      (b'relre', b'rr', b'')])
    (['', '', ''], [''])
    """
    r, d = _patternrootsanddirs(kindpats)

    # Append the parents as non-recursive/exact directories, since they must be
    # scanned to get to either the roots or the other exact directories.
    d.extend(sorted(util.dirs(d)))
    d.extend(sorted(util.dirs(r)))

    return r, d