app.py

from transformers import BlenderbotTokenizer, BlenderbotForConditionalGeneration
import gradio as grad

chat_tkn = BlenderbotTokenizer.from_pretrained("facebook/blenderbot-400M-distill")
mdl = BlenderbotForConditionalGeneration.from_pretrained("facebook/blenderbot-400M-distill")

def createHistory(message):
    history = grad.get_state() or []
    print(history)
    response = chat(message)
    history.append((message, response))
    grad.set_state(history)
    html = "<div class='chatbot'>"
    for user_msg, resp_msg in history:
        html += f"<div class='user_msg'>{user_msg}</div>"
        html += f"<div class='resp_msg'>{resp_msg}</div>"
    html += "</div>"
    return response

def chat(input):
     
    tkn_ids = chat_tkn(input+ chat_tkn.eos_token, return_tensors='pt')

    # bot responds
    chat_ids = mdl.generate(**tkn_ids)

    # print bot response
    response= "Alicia: {}".format(chat_tkn.decode(chat_ids[0], skip_special_tokens=True))

    return response

out=grad.Textbox(lines=20, label="dialog", placeholder="start conversation")
grad.Interface(createHistory, inputs="text",outputs=out).launch()