fix pdf bug

app.py

@@ -1,5 +1,6 @@
 import os
 import streamlit as st
+import tempfile
 
 from langchain_openai import OpenAIEmbeddings
 from langchain_openai.chat_models import ChatOpenAI
@@ -42,7 +43,10 @@ def add_text_to_chroma(text):
 
 
 def add_pdf_to_chroma(uploaded_pdf):
-    loader = PyPDFLoader(uploaded_pdf)
+    with tempfile.NamedTemporaryFile(delete=False, suffix=".pdf") as tmp_file:
+        tmp_file.write(uploaded_pdf.read())
+        tmp_file_path = tmp_file.name
+    loader = PyPDFLoader(tmp_file_path)
     pages = loader.load()
     embeddings = OpenAIEmbeddings()
     text_splitter = RecursiveCharacterTextSplitter(chunk_size=1000, chunk_overlap=150)