def test_set_scalar_subset_X(matrix_type, subset_func):
    adata = ad.AnnData(matrix_type(np.zeros((10, 10))))
    orig_X_val = adata.X.copy()
    subset_idx = slice_subset(adata.obs_names)

    adata_subset = adata[subset_idx, :]

    adata_subset.X = 1

    assert adata_subset.is_view
    assert np.all(asarray(adata[subset_idx, :].X) == 1)

    assert asarray((orig_X_val != adata.X)).sum() == mul(*adata_subset.shape)
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