Renamed variables for clarity and added clarifying comments

mavysavydav · mavysavydav · commit 79e1c72ee316 · 2021-06-02T10:17:09.000-07:00
Signed-off-by: David Y Liu &lt;davidyliuliu@gmail.com&gt;
diff --git a/sdk/python/feast/inference_helpers.py b/sdk/python/feast/inference_helpers.py
@@ -8,6 +8,9 @@
 def infer_entity_value_type_from_feature_views(
     entities: List[Entity], feature_views: List[FeatureView]
 ) -> List[Entity]:
+    """
+    Infer entity value type by examining schema of feature view input sources
+    """
     incomplete_entities = {
         entity.name: entity
         for entity in entities
@@ -17,32 +20,35 @@ def infer_entity_value_type_from_feature_views(
 
     for view in feature_views:
         if not (incomplete_entities_keys & set(view.entities)):
-            continue
+            continue  # skip if view doesn't contain any entities that need inference
+
         col_names_and_types = view.input.get_table_column_names_and_types()
         for entity_name in view.entities:
             if entity_name in incomplete_entities:
-                entity_col = list(
+                # get entity information from information extracted from the view input source
+                extracted_entity_name_type_pairs = list(
                     filter(lambda tup: tup[0] == entity_name, col_names_and_types)
                 )
-                if len(entity_col) == 0:
+                if len(extracted_entity_name_type_pairs) == 0:
                     # Doesn't mention inference error because would also be an error without inferencing
                     raise ValueError(
-                        f"""No column in the input source for the {view.name} FeatureView matches
-                        its Entity's name."""
+                        f"""No column in the input source for the {view.name} feature view matches
+                        its entity's name."""
                     )
 
                 entity = incomplete_entities[entity_name]
                 inferred_value_type = view.input.source_datatype_to_feast_value_type()(
-                    entity_col[0][1]
+                    extracted_entity_name_type_pairs[0][1]
                 )
+
                 if (
                     entity.value_type != ValueType.UNKNOWN
                     and entity.value_type != inferred_value_type
-                ) or (len(entity_col) > 1):
+                ) or (len(extracted_entity_name_type_pairs) > 1):
                     raise ValueError(
-                        f"""Entity value_type inference failed for {entity_name} Entity.
-                        Multiple viable matches. Please explicitly specify the Entity value_type
-                        for this Entity."""
+                        f"""Entity value_type inference failed for {entity_name} entity.
+                        Multiple viable matches. Please explicitly specify the entity value_type
+                        for this entity."""
                     )
 
                 entity.value_type = inferred_value_type
