added validation for no genre

app.py

@@ -22,8 +22,11 @@ all_genres = set()
 df["genres"].str.split("|").apply(all_genres.update)
 genre_list = sorted(all_genres)
 
-# 5) Updated recommendation function with year range
+# 5) Recommendation function with year range and genre check
 def recommend_by_genre_and_year_range(genre: str, start_year: int, end_year: int, top_k: int = 5) -> str:
+    if not genre:
+        return "⚠️ Please select a genre."
+
     mask_genre = metadata["genres"].str.lower().str.contains(genre.lower(), na=False)
     year_col = metadata["release_year"].fillna(0)
     mask_year = (year_col >= start_year) & (year_col <= end_year)
@@ -38,11 +41,11 @@ def recommend_by_genre_and_year_range(genre: str, start_year: int, end_year: int
         for _, row in picks.iterrows()
     )
 
-# 6) Gradio interface with year range inputs
+# 6) Gradio interface
 iface = gr.Interface(
     fn=recommend_by_genre_and_year_range,
     inputs=[
-        gr.Dropdown(choices=genre_list, label="Select Genre"),
+        gr.Dropdown(choices=genre_list, label="Select Genre", value=None),
         gr.Number(label="Start Year", value=1990, precision=0),
         gr.Number(label="End Year", value=1995, precision=0),
         gr.Slider(1, 10, step=1, label="Number of Recommendations", value=5),
@@ -51,8 +54,8 @@ iface = gr.Interface(
     title="🎬 Movie Recommender by Genre & Year Range",
     description="""
 Loads local MovieLens metadata (ml-32m), extracts release years from titles,
-normalizes genres, and filters by genre and custom year range. No typing needed — just click!
-""",
+normalizes genres, and filters by genre and a custom year range.
+"""
 )
 
 if __name__ == "__main__":