Update app.py

app.py

@@ -57,6 +57,16 @@ df_main = df_orig.select(
     "paper_id",
 )
 
+df_main = df_main.with_columns(
+    [
+        pl.when(pl.col(col) == "").then(None).otherwise(pl.col(col))
+        .cast(pl.Int64)
+        .fill_null(0)
+        .alias(col)
+        for col in ["upvotes", "num_comments"]
+    ]
+)
+
 df_main = df_main.rename(
     {
         "title": "Title",