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 _format_unhandled_exception_log(cls, exc, tb, add_newline, should_print_backtrace):
        exc_type = type(exc)
        exception_full_name = "{}.{}".format(exc_type.__module__, exc_type.__name__)
        exception_message = str(exc) if exc else "(no message)"
        maybe_newline = "\n" if add_newline else ""
        return cls._UNHANDLED_EXCEPTION_LOG_FORMAT.format(
            exception_type=exception_full_name,
            backtrace=cls._format_traceback(
                traceback_lines=traceback.format_tb(tb),
                should_print_backtrace=should_print_backtrace,
            ),
            exception_message=exception_message,
            maybe_newline=maybe_newline,
        )