add some notes

models/rank/logistic_regression/data/get_slot_data.py

@@ -79,8 +79,7 @@ class Reader(dg.MultiSlotDataGenerator):
                 v = i[1]
                 for j in v:
                     s += " " + k + ":" + str(j)
-            print(s.strip())
-            yield None
+            print(s.strip())  # add print for data preprocessing
 
         return data_iter
 

models/rank/logistic_regression/readme.md

@@ -156,9 +156,7 @@ class Reader(dg.MultiSlotDataGenerator):
                 v = i[1]
                 for j in v:
                     s += " " + k + ":" + str(j)
-            print(s.strip())
-            yield None
-
+            print(s.strip()) # add print for data preprocessing
         return data_iter