Fixed AnchorTabular length discrepancy between feature and names field. (#902)

Fixed AnchorTabular length discrepancy between feature and names field.

Author: RobertSamoilescu

alibi/explainers/anchors/anchor_tabular.py

@@ -912,9 +912,10 @@ def add_names_to_exp(self, explanation: dict) -> None:
         """
 
         anchor_idxs = explanation['feature']
-        explanation['names'] = []
-        explanation['feature'] = [self.enc2feat_idx[idx] for idx in anchor_idxs]
         ordinal_ranges = {self.enc2feat_idx[idx]: [float('-inf'), float('inf')] for idx in anchor_idxs}
+        explanation['feature'] = list(ordinal_ranges.keys())
+        explanation['names'] = []
+
         for idx in set(anchor_idxs) - self.cat_lookup.keys():
             feat_id = self.enc2feat_idx[idx]  # feature col. id
             if 0 in self.ord_lookup[idx]:  # tells if the feature in X falls in a higher or lower bin