non null data

app.py

@@ -84,6 +84,7 @@ def extract_data(feed):
         for p in pages:
             data.append(p.extract_text())
         
+        
     return None 
 
 
@@ -94,11 +95,13 @@ def extract_data(feed):
 
 def main():
     uploaded_file = st.file_uploader('Choose your .pdf file', type="pdf")
-    if st.button("Make PPT"):
-        ai_ppt(data)
+    
     if uploaded_file is not None:
         extract_data(uploaded_file)
         
+        if st.button("Make PPT"):
+            ai_ppt(data)
+
         binary_data = uploaded_file.getvalue()
         pdf_viewer(input=binary_data,
                 width=700)