231217: first version of app

app.py

@@ -1,8 +1,63 @@
 import gradio as gr
+from PyPDF2 import PdfReader
+from langchain.text_splitter import CharacterTextSplitter
+from langchain.embeddings.openai import OpenAIEmbeddings
+from langchain.vectorstores import FAISS
+from langchain.chains.question_answering import load_qa_chain
+from langchain.llms import OpenAI
+from langchain.callbacks import get_openai_callback
+import os
 
-def greet(name):
-    return "Hello " + name + "!!"
+def process_pdf_and_answer_question(pdf, user_question, openai_key):
+    if pdf is None or user_question == "":
+        return "Please upload a PDF and enter a question."
 
-iface = gr.Interface(fn=greet, inputs="text", outputs="text")
-iface.launch()
+    if not pdf.name.lower().endswith('.pdf'):
+        return "Please upload a PDF file."
 
+    pdf_reader = PdfReader(pdf)
+    text = ""
+    for page in pdf_reader.pages:
+        text += page.extract_text()
+
+    text_splitter = CharacterTextSplitter(
+        separator="\n",
+        chunk_size=1000,
+        chunk_overlap=200,
+        length_function=len
+    )
+    chunks = text_splitter.split_text(text)
+
+    # Set OpenAI API key from the provided input
+    os.environ["OPENAI_API_KEY"] = openai_key
+
+    embeddings = OpenAIEmbeddings()
+    knowledge_base = FAISS.from_texts(chunks, embeddings)
+
+    docs = knowledge_base.similarity_search(user_question)
+    llm = OpenAI()
+    chain = load_qa_chain(llm, chain_type="stuff")
+    with get_openai_callback() as cb:
+        response = chain.run(input_documents=docs, question=user_question)
+        print(cb)
+
+    return response
+
+with gr.Blocks() as demo:
+    with gr.Accordion("Enter OpenAI API Key for the app to work"):
+        openai_key = gr.Textbox(label="API Key", placeholder="Enter your OpenAI API Key here")
+
+    gr.Markdown("Q&A on your PDF")
+    with gr.Row():
+        pdf = gr.File(label="Upload a PDF")
+        user_question = gr.Textbox(label="Ask a question about this PDF:")
+        answer_button = gr.Button("Answer")
+    response = gr.Textbox(label="Response", interactive=False)
+
+    answer_button.click(
+        fn=process_pdf_and_answer_question,
+        inputs=[pdf, user_question, openai_key],
+        outputs=response
+    )
+
+demo.launch()

requirements.txt

@@ -0,0 +1,7 @@
+gradio==4.10.0
+langchain
+PyPDF2==3.0.1
+python-dotenv==1.0.0
+openai==0.27.6
+faiss-cpu==1.7.4
+tiktoken==0.4.0