def test_drop_obs_column():
    adata = ad.AnnData(np.array(X_list), obs=obs_dict, dtype="int32")

    subset = adata[:2]
    assert subset.is_view
    # returns a copy of obs
    assert subset.obs.drop(columns=["oanno1"]).columns.tolist() == ["oanno2", "oanno3"]
    assert subset.is_view
    # would modify obs, so it should actualize subset and not modify adata
    subset.obs.drop(columns=["oanno1"], inplace=True)
    assert not subset.is_view
    assert subset.obs.columns.tolist() == ["oanno2", "oanno3"]

    assert adata.obs.columns.tolist() == ["oanno1", "oanno2", "oanno3"]
def visitdir(self, dir):
        dir = normalizerootdir(dir, "visitdir")
        if not self._m2.visitdir(dir):
            return self._m1.visitdir(dir)

        if self._m2.visitdir(dir) == "all":
            # There's a bug here: If m1 matches file 'dir/file' and m2 excludes
            # 'dir' (recursively), we should still visit 'dir' due to the
            # exception we have for exact matches.
            return False
        return bool(self._m1.visitdir(dir))