Update app.py

app.py

@@ -37,13 +37,14 @@ if "query_engine" not in st.session_state:
     st.session_state.query_engine = None
 
 with st.sidebar:
-    st.subheader("Upload your Documents Here: ")
+    st.subheader("Upload your pdf Documents Here: ")
     pdf_files = st.file_uploader("Choose your PDF Files and Press OK", type=['pdf'], accept_multiple_files=True)    
     if not pdf_files:
         st.warning("请上传文档文件")
         st.stop()      
     else:
         uploadedfile_path=generate_random_string(20)                
+        os.makedirs(uploadedfile_path)
         for pdf_file in pdf_files:
             file_path = os.path.join(uploadedfile_path, pdf_file.name)
             with open(file_path, 'wb') as f: