Update app.py

app.py

@@ -25,6 +25,11 @@ model_options = {
 
 # Main function for the Gradio interface
 def find_similar_texts(model_name, input_text):
+
+    # Check whether model has been selected
+    if not model_name:
+        return "You forgot to choose a sentence-transformer."
+    
     # Check whether there are abstracts matching the text input
     input_embedding_mini = model_all_Mini.encode(input_text).reshape(1, -1)
     embedding_matrix_mini = np.vstack(text_embeddings['embedding_all-MiniLM-L6-v2'])