app.py

import json
import openai
import tiktoken
import numpy as np
import pandas as pd
import gradio as gr
import pickle

COMPLETIONS_MODEL = "text-davinci-003"
EMBEDDING_MODEL = "text-embedding-ada-002"

with open("document_embeddings_clean_code.pickle", "rb") as document_embeddings_clean_code:
  document_embeddings = pickle.load(document_embeddings_clean_code)
  
df = pd.read_csv('./clean_code_processed.csv')
df = df.set_index(["title", "section"])
df = df[df.tokens > 40]
df_for_embeddings = df


def get_embedding(text, model=EMBEDDING_MODEL):
    result = openai.Embedding.create(
      model=model,
      input=text
    )
    return result["data"][0]["embedding"]

def vector_similarity(x, y):
    """
    Returns the similarity between two vectors.
    
    Because OpenAI Embeddings are normalized to length 1, the cosine similarity is the same as the dot product.
    """
    return np.dot(np.array(x), np.array(y))

def order_document_sections_by_query_similarity(query, contexts):
    """
    Find the query embedding for the supplied query, and compare it against all of the pre-calculated document embeddings
    to find the most relevant sections. 
    
    Return the list of document sections, sorted by relevance in descending order.
    """
    query_embedding = get_embedding(query)
    
    document_similarities = sorted([
        (vector_similarity(query_embedding, doc_embedding), doc_index) for doc_index, doc_embedding in contexts.items()
    ], reverse=True)
    
    return document_similarities

def construct_prompt(question, context_embeddings, df):
    """
    Fetch relevant 
    """
    most_relevant_document_sections = order_document_sections_by_query_similarity(question, context_embeddings)
    
    chosen_sections = []
    chosen_sections_len = 0
    chosen_sections_indexes = []
     
    for _, section_index in most_relevant_document_sections:
        # Add contexts until we run out of space.        
        tokens = df._get_value(section_index, "tokens")
        if type(tokens) != np.int64:
            continue
        
        chosen_sections_len += df._get_value(section_index, "tokens") + separator_len
        if chosen_sections_len > MAX_SECTION_LEN:
            break
            
        chosen_sections.append(SEPARATOR + df._get_value(section_index, "content").replace("\n", " "))
        chosen_sections_indexes.append(section_index)
            
    # Useful diagnostic information
    print(f"Selected {len(chosen_sections)} document sections:")
    print("\n".join(str(index) for index in chosen_sections_indexes))
    
    header = """Answer the question as truthfully as possible using the provided context, and if the answer is not contained within the text below, say "I don't know."\n\nContext:\n"""
    
    return (header + "".join(chosen_sections) + "\n\n Q: " + question + "\n A:", chosen_sections_indexes)



MAX_SECTION_LEN = 2000
SEPARATOR = "\n* "
ENCODING = "gpt2"  # encoding for text-davinci-003

encoding = tiktoken.get_encoding(ENCODING)
separator_len = len(encoding.encode(SEPARATOR))

COMPLETIONS_API_PARAMS = {
    # We use temperature of 0.0 because it gives the most predictable, factual answer.
    "temperature": 0.0,
    "max_tokens": 1500,
    "model": COMPLETIONS_MODEL,
}

def answer_query_with_context(
    query,
    df,
    document_embeddings
):
    prompt, chosen_sections_indexes = construct_prompt(
        query,
        document_embeddings,
        df
    )

    for i in range(len(chosen_sections_indexes)):
        chosen_sections_indexes[i] = chosen_sections_indexes[i][0]
    
    response = openai.Completion.create(
                prompt=prompt,
                **COMPLETIONS_API_PARAMS
            )

    return (response["choices"][0]["text"].strip(" \n"), chosen_sections_indexes)

def handle(question):
    answer, related_documents = answer_query_with_context(question, df_for_embeddings, document_embeddings)
    return answer + "\n\nRelated chapters:\n" + "\n".join(related_documents)

demo = gr.Interface(
    fn=handle,
    inputs="text",
    outputs="text",
    cache_examples=False,
    examples=[
      "How to properly name a variable?",
      "How to write a good comment?",
      "What are best practices of unit testing?",
    ]
)

demo.launch()