Returns self.run_stats over search params as pandas dataframe.

def run_stats_df(self):
        """Returns self.run_stats over search params as pandas dataframe."""

        run_stats_df = []
        for x in self.run_stats:
            search_results = {**x["search_params"]}
            search_results["score"] = x["score"]
            run_stats_df.append(search_results)
        return pd.DataFrame(run_stats_df)