diff --git a/tube/etl/indexers/aggregation/parser.py b/tube/etl/indexers/aggregation/parser.py
index 5b36c67d..70f3d2e0 100644
--- a/tube/etl/indexers/aggregation/parser.py
+++ b/tube/etl/indexers/aggregation/parser.py
@@ -113,10 +113,11 @@ def add_program_name_to_parent(self):
         found_program = -1
         i = -1
         for path in self.mapping["parent_props"]:
-            p = path.get("path")
+            p = path["path"]
             i += 1
             if p.startswith("program"):
                 found_program = i
+                break
         if found_program == -1:
             self.mapping["parent_props"].append(
                 {"path": "programs[{PROGRAM_N}:name]".format(PROGRAM_N=PROGRAM_NAME)}
diff --git a/tube/etl/indexers/base/translator.py b/tube/etl/indexers/base/translator.py
index 4367b3b0..29859a00 100644
--- a/tube/etl/indexers/base/translator.py
+++ b/tube/etl/indexers/base/translator.py
@@ -72,7 +72,12 @@ def write(self, df):
     def get_props_from_data_row(self, df, props, to_tuple=False):
         if df.isEmpty():
             return df.mapValues(get_props_empty_values(props))
+        # names is dictionary which maps from the name of source fields in datatable to the list of ids
+        # of properties in dataframe
+        # example: names = {"gender": [1, 2], project_name: [3]}
         names = {}
+        # values is a dictionary which defines the mapping values (if exist) for each field.
+        # values = {"code": {1: {"male": "M", "female": "F"}, 2: {"male": "Male", "female": "Female}}, "project_name": {}}
         values = {}
         for p in props:
             n = names.get(p.src, [])