def METHOD_NAME(ds, labels, column="observed"):
    """Compute completeness by bin using given column name"""
    result = ds.groupby("bin")[column].agg(["sum", "count"])
    result["completeness"] = result["sum"] / result["count"]
    result = result[["completeness"]]
    result.index = labels
    overall = ds[column].sum() / len(ds)
    result.loc["overall", "completeness"] = overall
    return result