Update app.py

app.py

@@ -33,7 +33,7 @@ df_main = df_orig.select(
 # TODO: Fix this once https://github.com/gradio-app/gradio/issues/10916 is fixed # noqa: FIX002, TD002
 # format numbers as strings
 df_main = df_main.with_columns(
-    [pl.col(col).cast(pl.Utf8).fill_null("").alias(col) for col in ["upvotes", "num_comments"]]
+    [pl.col(col).fill_null(0).cast(pl.Int64).alias(col) for col in ["upvotes", "num_comments"]]
 )
 
 df_main = df_main.rename(