code: def get_posterior_mean_ratio_scores_vs_background(self):
          '''
          Returns
          -------
              pd.DataFrame of posterior mean  scores vs background
          '''
          df = self.get_term_and_background_counts()
          df['Log Posterior Mean Ratio'] = self._get_posterior_mean_ratio_from_counts(df['corpus'],
                                                                                      df['background'])
          return df.sort_values('Log Posterior Mean Ratio', ascending=Falsef get_posterior_mean_ratio_scores_vs_background(self):
          '''
          Returns
          -------
              pd.DataFrame of posterior mean  scores vs background
          '''
          df = self.get_term_and_background_counts()
          df['Log Posterior Mean Ratio'] = self._get_posterior_mean_ratio_from_counts(df['corpus'],
                                                                                      df['background'])
          return df.sort_values('Log Posterior Mean Ratio', ascending=False)
docs: Returns
          -------
              pd.DataFrame of posterior mean  scores vs background