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 _regex(kind, pat, globsuffix):
    """Convert a (normalized) pattern of any kind into a regular expression.
    globsuffix is appended to the regexp of globs."""
    if not pat and kind in ("glob", "relpath"):
        return ""
    if kind == "re":
        return pat
    if kind in ("path", "relpath"):
        if pat == ".":
            return ""
        return util.re.escape(pat) + "(?:/|$)"
    if kind == "rootfilesin":
        if pat == ".":
            escaped = ""
        else:
            # Pattern is a directory name.
            escaped = util.re.escape(pat) + "/"
        # Anything after the pattern must be a non-directory.
        return escaped + "[^/]+$"
    if kind == "relglob":
        return "(?:|.*/)" + _globre(pat) + globsuffix
    if kind == "relre":
        if pat.startswith("^"):
            return pat
        return ".*" + pat
    return _globre(pat) + globsuffix