Update app.py

app.py

@@ -125,8 +125,14 @@ with st.sidebar:
 
         if in_headline_type!='No headlines':
             in_headlines = st.text_area("Headlines: ", placeholder="Enter each headline in one line. e.g.,\nWelcome\nConcise Description\nAdditional Info", on_change=None, height=200)
-            in_headlines = in_headlines.split('\n')
-            in_headlines = [element.strip() for element in in_headlines]
+
+            if not in_headlines:
+                in_headline_type = '<|MASK|>'
+                in_headlines = '<|MASK|>'
+            else:
+                in_headlines = in_headlines.split('\n')
+                in_headlines = [element.strip() for element in in_headlines]
+
         else:
             in_headline_type = '<|EMPTY|>'
             in_headlines = '<|EMPTY|>'