nan values

b2w-reviews01.py

@@ -82,9 +82,7 @@ class Reviews(datasets.GeneratorBasedBuilder):
 
             row["recommend_to_a_friend"] = recommend_key.get(row["recommend_to_a_friend"], None)
 
-            to_int_list = ["overall_rating"]
-            for row_value in to_int_list:
-                row[row_value] = int(row[row_value])
+            row["overall_rating"] = int(row["overall_rating"])
 
             try:
                 row["reviewer_birth_year"] = int(float(row["reviewer_birth_year"]))
@@ -92,7 +90,7 @@ class Reviews(datasets.GeneratorBasedBuilder):
                 row["reviewer_birth_year"] = None
             
             for key, value in row.items():
-                if value == "nan":
+                if isinstance(value, str) and not value.strip():
                     row[key] = None
 
             return row