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 refresh(self):
        """refreshes the Gtk.Liststore"""
        self.backendid_to_iter = {}
        self.liststore.clear()

        # Sort backends
        # 1, put default backend on top
        # 2, sort backends by human name
        backends = list(self.req.get_all_backends(disabled=True))
        backends = sorted(backends,
                          key=lambda backend: (not backend.is_default(),
                                               backend.get_human_name()))

        for backend in backends:
            self.add_backend(backend)
            self.on_backend_state_changed(None, backend.get_id())