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 select_backend(self, backend_id=None):
        """
        Selects the backend corresponding to backend_id.
        If backend_id is none, refreshes the current configuration panel.

        @param backend_id: the id of the backend to select
        """
        selection = self.get_selection()
        if backend_id in self.backendid_to_iter:
            backend_iter = self.backendid_to_iter[backend_id]
            if selection:
                selection.select_iter(backend_iter)
        else:
            if self._get_selected_path():
                # We just reselect the currently selected entry
                self.on_select_row()
            else:
                # If nothing is selected, we select the first entry
                if selection:
                    selection.select_path("0")
        self.dialog.on_backend_selected(self.get_selected_backend_id())