Create app.py

app.py

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+# to-do: Enable downloading multiple patent PDFs via corresponding links 
+import sys
+import os
+import re
+import shutil
+import time
+import streamlit as st
+import nltk
+import tempfile
+import subprocess
+
+# Pin NLTK to version 3.9.1
+REQUIRED_NLTK_VERSION = "3.9.1"
+subprocess.run([sys.executable, "-m", "pip", "install", f"nltk=={REQUIRED_NLTK_VERSION}"])
+
+# Set up temporary directory for NLTK resources
+nltk_data_path = os.path.join(tempfile.gettempdir(), "nltk_data")
+os.makedirs(nltk_data_path, exist_ok=True)
+nltk.data.path.append(nltk_data_path)
+
+# Download 'punkt_tab' for compatibility
+try:
+    print("Ensuring NLTK 'punkt_tab' resource is downloaded...")
+    nltk.download("punkt_tab", download_dir=nltk_data_path)
+except Exception as e:
+    print(f"Error downloading NLTK 'punkt_tab': {e}")
+    raise e
+
+sys.path.append(os.path.abspath("."))
+from langchain.chains import ConversationalRetrievalChain
+from langchain.memory import ConversationBufferMemory
+from langchain.llms import OpenAI
+from langchain.document_loaders import UnstructuredPDFLoader
+from langchain.vectorstores import Chroma
+from langchain.embeddings import HuggingFaceEmbeddings
+from langchain.text_splitter import NLTKTextSplitter
+from patent_downloader import PatentDownloader
+
+PERSISTED_DIRECTORY = tempfile.mkdtemp()
+
+# Fetch API key securely from the environment
+OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
+if not OPENAI_API_KEY:
+    st.error("Critical Error: OpenAI API key not found in the environment variables. Please configure it.")
+    st.stop()
+
+def check_poppler_installed():
+    if not shutil.which("pdfinfo"):
+        raise EnvironmentError(
+            "Poppler is not installed or not in PATH. Install 'poppler-utils' for PDF processing."
+        )
+
+check_poppler_installed()
+
+def load_docs(document_path):
+    try:
+        loader = UnstructuredPDFLoader(
+            document_path,
+            mode="elements",
+            strategy="fast",
+            ocr_languages=None
+        )
+        documents = loader.load()
+        text_splitter = NLTKTextSplitter(chunk_size=1000)
+        split_docs = text_splitter.split_documents(documents)
+        
+        # Filter metadata to only include str, int, float, or bool
+        for doc in split_docs:
+            if hasattr(doc, "metadata") and isinstance(doc.metadata, dict):
+                doc.metadata = {
+                    k: v for k, v in doc.metadata.items()
+                    if isinstance(v, (str, int, float, bool))
+                }
+        return split_docs
+    except Exception as e:
+        st.error(f"Failed to load and process PDF: {e}")
+        st.stop()
+
+def already_indexed(vectordb, file_name):
+    indexed_sources = set(
+        x["source"] for x in vectordb.get(include=["metadatas"])["metadatas"]
+    )
+    return file_name in indexed_sources
+
+def load_chain(file_name=None):
+    loaded_patent = st.session_state.get("LOADED_PATENT")
+
+    vectordb = Chroma(
+        persist_directory=PERSISTED_DIRECTORY,
+        embedding_function=HuggingFaceEmbeddings(),
+    )
+    if loaded_patent == file_name or already_indexed(vectordb, file_name):
+        st.write("✅ Already indexed.")
+    else:
+        vectordb.delete_collection()
+        docs = load_docs(file_name)
+        st.write("🔍 Number of Documents: ", len(docs))
+
+        vectordb = Chroma.from_documents(
+            docs, HuggingFaceEmbeddings(), persist_directory=PERSISTED_DIRECTORY
+        )
+        vectordb.persist()
+        st.session_state["LOADED_PATENT"] = file_name
+
+    memory = ConversationBufferMemory(
+        memory_key="chat_history",
+        return_messages=True,
+        input_key="question",
+        output_key="answer",
+    )
+    return ConversationalRetrievalChain.from_llm(
+        OpenAI(temperature=0, openai_api_key=OPENAI_API_KEY),
+        vectordb.as_retriever(search_kwargs={"k": 3}),
+        return_source_documents=False,
+        memory=memory,
+    )
+
+def extract_patent_number(url):
+    pattern = r"/patent/([A-Z]{2}\d+)"
+    match = re.search(pattern, url)
+    return match.group(1) if match else None
+
+def download_pdf(patent_number):
+    try:
+        patent_downloader = PatentDownloader(verbose=True)
+        output_path = patent_downloader.download(patents=patent_number, output_path=tempfile.gettempdir())
+        return output_path[0]
+    except Exception as e:
+        st.error(f"Failed to download patent PDF: {e}")
+        st.stop()
+
+if __name__ == "__main__":
+    st.set_page_config(
+        page_title="Patent Chat: Google Patents Chat Demo",
+        page_icon="📖",
+        layout="wide",
+        initial_sidebar_state="expanded",
+    )
+    st.header("📖 Patent Chat: Google Patents Chat Demo")
+
+    # Fetch query parameters safely
+    query_params = st.query_params
+    default_patent_link = query_params.get("patent_link", "https://patents.google.com/patent/US8676427B1/en")
+    
+    # Input for Google Patent Link
+    patent_link = st.text_area("Enter Google Patent Link:", value=default_patent_link, height=100)
+
+    # Button to start processing
+    if st.button("Load and Process Patent"):
+        if not patent_link:
+            st.warning("Please enter a Google patent link to proceed.")
+            st.stop()
+
+        patent_number = extract_patent_number(patent_link)
+        if not patent_number:
+            st.error("Invalid patent link format. Please provide a valid Google patent link.")
+            st.stop()
+
+        st.write(f"Patent number: **{patent_number}**")
+
+        pdf_path = os.path.join(tempfile.gettempdir(), f"{patent_number}.pdf")
+        if os.path.isfile(pdf_path):
+            st.write("✅ File already downloaded.")
+        else:
+            st.write("📥 Downloading patent file...")
+            pdf_path = download_pdf(patent_number)
+            st.write(f"✅ File downloaded: {pdf_path}")
+
+        st.write("🔄 Loading document into the system...")
+
+        # Persist the chain in session state to prevent reloading
+        if "chain" not in st.session_state or st.session_state.get("loaded_file") != pdf_path:
+            st.session_state.chain = load_chain(pdf_path)
+            st.session_state.loaded_file = pdf_path
+            st.session_state.messages = [{"role": "assistant", "content": "Hello! How can I assist you with this patent?"}]
+
+        st.success("🚀 Document successfully loaded! You can now start asking questions.")
+
+    # Initialize messages if not already done
+    if "messages" not in st.session_state:
+        st.session_state.messages = [{"role": "assistant", "content": "Hello! How can I assist you with this patent?"}]
+
+    # Display previous chat messages
+    for message in st.session_state.messages:
+        with st.chat_message(message["role"]):
+            st.markdown(message["content"])
+
+    if "chain" in st.session_state:
+        if user_input := st.chat_input("What is your question?"):
+            st.session_state.messages.append({"role": "user", "content": user_input})
+            with st.chat_message("user"):
+                st.markdown(user_input)
+
+            with st.chat_message("assistant"):
+                message_placeholder = st.empty()
+                full_response = ""
+
+                with st.spinner("Generating response..."):
+                    try:
+                        assistant_response = st.session_state.chain({"question": user_input})
+                        full_response = assistant_response["answer"]
+                    except Exception as e:
+                        full_response = f"An error occurred: {e}"
+
+                message_placeholder.markdown(full_response)
+                st.session_state.messages.append({"role": "assistant", "content": full_response})
+    else:
+        st.info("Press the 'Load and Process Patent' button to start processing.")