app.py

import json 
import gradio as gr
import os
import requests

hf_token = os.getenv('HF_TOKEN')
api_url = os.getenv('API_URL') 
headers = {
    'Content-Type': 'application/json',
}

system_message = "\nYou are a helpful, respectful and honest assistant. Always answer as helpfully as possible, while being safe.  Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature.\n\nIf a question does not make any sense, or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information."
title = "Llama2 70B Chatbot"
description = """LLama2 demo"""
css = """.toast-wrap { display: none !important } """
examples=[
    'Explain the phenomenon of Quantum tunneling?',
    'Explain few sentences about exoplanets',
    'What is Sea surface temperature? how is it measured?',
    ]


def predict(message, chatbot):
    
    input_prompt = f"[INST] <<SYS>>\n{system_message}\n<</SYS>>\n\n "
    for interaction in chatbot:
        input_prompt = input_prompt + str(interaction[0]) + " [/INST] " + str(interaction[1]) + " </s><s> [INST] "

    input_prompt = input_prompt + str(message) + " [/INST] "

    data = {
        "inputs": input_prompt,
        "parameters": {"max_new_tokens":256}
    }

    response = requests.post(api_url, headers=headers, data=json.dumps(data), auth=('hf', hf_token), stream=True)
    
    partial_message = ""
    for line in response.iter_lines():
        if line:  # filter out keep-alive new lines
            # Decode from bytes to string
            decoded_line = line.decode('utf-8')

            # Remove 'data:' prefix 
            if decoded_line.startswith('data:'):
                json_line = decoded_line[5:]  # Exclude the first 5 characters ('data:')
            else:
                gr.Warning(f"This line does not start with 'data:': {decoded_line}")
                continue

            # Load as JSON
            try:
                json_obj = json.loads(json_line)
                if 'token' in json_obj:
                    partial_message = partial_message + json_obj['token']['text'] 
                    yield partial_message
                elif 'error' in json_obj:
                    yield json_obj['error'] + '. Please refresh and try again with an appropriate smaller input prompt.'
                else:
                    gr.Warning(f"The key 'token' does not exist in this JSON object: {json_obj}")

            except json.JSONDecodeError:
                gr.Warning(f"This line is not valid JSON: {json_line}")
                continue
            except KeyError as e:
                gr.Warning(f"KeyError: {e} occurred for JSON object: {json_obj}")
                continue

gr.ChatInterface(predict, title=title, description=description, css=css, examples=examples, cache_examples=True).queue(concurrency_count=75).launch()