Update app.py

app.py

@@ -6,7 +6,7 @@ st.title("What's the category?")
 
 text = st.text_input("Enter words")
 
-if text is not None:
+if text is not None and text is not "":
     candidate_labels = ['lifestyle', 'technology', 'entertainment', 'news']
     res = classifier(text, candidate_labels)