fix to processer.py

Author: Luigi Dello Stritto

machine_learning_hep/processer.py

@@ -423,11 +423,12 @@ def dfuse(df_spec):
                             self.logger.info('exploding dataframe %s on variable %s', base, on)
                             dfs[base] = dfs[base].explode(on)
                         dfs[out] = dfmerge(dfs[base], dfs[ref], left_on=['df', on], right_index=True)
-                        dfs[out].index.name = 'MergedIndex'
-                        dfs[out] = dfs[out].reset_index()
-                        sorted_df = dfs[out].sort_values('fMultZeqNTracksPV', ascending=False)
-                        dfs[out] = sorted_df.drop_duplicates('MergedIndex')
-                        dfs[out] = dfs[out].sort_values('MergedIndex', ascending=True)
+                        if not is_numeric_dtype(dfs[base][on]):
+                            dfs[out].index.name = 'MergedIndex'
+                            dfs[out] = dfs[out].reset_index()
+                            sorted_df = dfs[out].sort_values('fMultZeqNTracksPV', ascending=False)
+                            dfs[out] = sorted_df.drop_duplicates('MergedIndex')
+                            dfs[out] = dfs[out].sort_values('MergedIndex', ascending=True)
                     else:
                         var = self.df_read[ref]['index']
                         self.logger.info('merging %s with %s on %s (default) into %s', base, ref, var, out)