def test_view_setattr_machinery(attr, subset_func, subset_func2):
    # Tests that setting attributes on a view doesn't mess anything up too bad
    adata = gen_adata((10, 10))
    view = adata[subset_func(adata.obs_names), subset_func2(adata.var_names)]

    actual = view.copy()
    setattr(view, attr, getattr(actual, attr))
    assert_equal(actual, view, exact=True)
def _testrefastpath(repat):
    """Test if a re pattern can use fast path.

    That is, for every "$A/$B" path the pattern matches, "$A" must also be
    matched,

    Return True if we're sure it is. Return False otherwise.
    """
    # XXX: It's very hard to implement this. These are what need to be
    # supported in production and tests. Very hacky. But we plan to get rid
    # of re matchers eventually.

    # Rules like "(?!experimental/)"
    if repat.startswith("(?!") and repat.endswith(")") and repat.count(")") == 1:
        return True

    # Rules used in doctest
    if repat == "(i|j)$":
        return True

    return False