Streamlit code changes

pdfquery.py

@@ -0,0 +1,36 @@
+import os
+from langchain.embeddings.openai import OpenAIEmbeddings
+from langchain.text_splitter import RecursiveCharacterTextSplitter
+from langchain.vectorstores import Chroma
+from langchain.document_loaders import PyPDFium2Loader
+from langchain.chains.question_answering import load_qa_chain
+from langchain.llms import OpenAI
+
+
+class PDFQuery:
+    def __init__(self, openai_api_key = None) -> None:
+        self.embeddings = OpenAIEmbeddings(openai_api_key=openai_api_key)
+        os.environ["OPENAI_API_KEY"] = openai_api_key
+        self.text_splitter = RecursiveCharacterTextSplitter(chunk_size=1000, chunk_overlap=200)
+        self.llm = OpenAI(temperature=0, openai_api_key=openai_api_key)
+        self.chain = None
+        self.db = None
+
+    def ask(self, question: str) -> str:
+        if self.chain is None:
+            response = "Please, add a document."
+        else:
+            docs = self.db.get_relevant_documents(question)
+            response = self.chain.run(input_documents=docs, question=question)
+        return response
+
+    def ingest(self, file_path: os.PathLike) -> None:
+        loader = PyPDFium2Loader(file_path)
+        documents = loader.load()
+        splitted_documents = self.text_splitter.split_documents(documents)
+        self.db = Chroma.from_documents(splitted_documents, self.embeddings).as_retriever()
+        self.chain = load_qa_chain(OpenAI(temperature=0), chain_type="stuff")
+
+    def forget(self) -> None:
+        self.db = None
+        self.chain = None

streamlitui.py

@@ -0,0 +1,90 @@
+import os
+import tempfile
+import streamlit as st
+from streamlit_chat import message
+from pdfquery import PDFQuery
+
+st.set_page_config(page_title="ChatPDF")
+
+
+def display_messages():
+    st.subheader("Chat")
+    for i, (msg, is_user) in enumerate(st.session_state["messages"]):
+        message(msg, is_user=is_user, key=str(i))
+    st.session_state["thinking_spinner"] = st.empty()
+
+
+def process_input():
+    if st.session_state["user_input"] and len(st.session_state["user_input"].strip()) > 0:
+        user_text = st.session_state["user_input"].strip()
+        with st.session_state["thinking_spinner"], st.spinner(f"Thinking"):
+            query_text = st.session_state["pdfquery"].ask(user_text)
+
+        st.session_state["messages"].append((user_text, True))
+        st.session_state["messages"].append((query_text, False))
+
+
+def read_and_save_file():
+    st.session_state["pdfquery"].forget()  # to reset the knowledge base
+    st.session_state["messages"] = []
+    st.session_state["user_input"] = ""
+
+    for file in st.session_state["file_uploader"]:
+        with tempfile.NamedTemporaryFile(delete=False) as tf:
+            tf.write(file.getbuffer())
+            file_path = tf.name
+
+        with st.session_state["ingestion_spinner"], st.spinner(f"Ingesting {file.name}"):
+            st.session_state["pdfquery"].ingest(file_path)
+        os.remove(file_path)
+
+
+def is_openai_api_key_set() -> bool:
+    return len(st.session_state["OPENAI_API_KEY"]) > 0
+
+
+def main():
+    if len(st.session_state) == 0:
+        st.session_state["messages"] = []
+        st.session_state["OPENAI_API_KEY"] = os.environ.get("OPENAI_API_KEY", "")
+        if is_openai_api_key_set():
+            st.session_state["pdfquery"] = PDFQuery(st.session_state["OPENAI_API_KEY"])
+        else:
+            st.session_state["pdfquery"] = None
+
+    st.header("ChatPDF")
+
+    if st.text_input("OpenAI API Key", value=st.session_state["OPENAI_API_KEY"], key="input_OPENAI_API_KEY", type="password"):
+        if (
+            len(st.session_state["input_OPENAI_API_KEY"]) > 0
+            and st.session_state["input_OPENAI_API_KEY"] != st.session_state["OPENAI_API_KEY"]
+        ):
+            st.session_state["OPENAI_API_KEY"] = st.session_state["input_OPENAI_API_KEY"]
+            if st.session_state["pdfquery"] is not None:
+                st.warning("Please, upload the files again.")
+            st.session_state["messages"] = []
+            st.session_state["user_input"] = ""
+            st.session_state["pdfquery"] = PDFQuery(st.session_state["OPENAI_API_KEY"])
+
+    st.subheader("Upload a document")
+    st.file_uploader(
+        "Upload document",
+        type=["pdf"],
+        key="file_uploader",
+        on_change=read_and_save_file,
+        label_visibility="collapsed",
+        accept_multiple_files=True,
+        disabled=not is_openai_api_key_set(),
+    )
+
+    st.session_state["ingestion_spinner"] = st.empty()
+
+    display_messages()
+    st.text_input("Message", key="user_input", disabled=not is_openai_api_key_set(), on_change=process_input)
+
+    st.divider()
+    st.markdown("Source code: [Github](https://github.com/Anil-matcha/ChatPDF)")
+
+
+if __name__ == "__main__":
+    main()