Langchain ChatGPT no memory demo

langchain-no-memory.py

from typing import List
from pydantic import BaseModel, Field
from langchain_core.globals import set_debug
from langchain_core.output_parsers.json import JsonOutputParser
from langchain_core.prompts.prompt import PromptTemplate
from langchain_openai import ChatOpenAI
from langchain_community.callbacks import get_openai_callback
from langchain.chains import ConversationChain
from langchain_community.llms import OpenAI



set_debug(False)
model_name = 'gpt-4o'

class ListResponseModel(BaseModel):
    data: List[str] = Field(title="List of names, excluding any item already mentioned.")

parser = JsonOutputParser(pydantic_object=ListResponseModel)


prompt = PromptTemplate.from_template(
    'In JSON format, give me a list of {topic}.'
    '{format_instructions}',
).partial(format_instructions=parser.get_format_instructions())

model = ChatOpenAI(model=model_name, temperature=0.03)
chain = prompt | model | parser

for _ in range(3):
    with get_openai_callback() as cb:
        # WARN ChatGPT has no memory between this and previous converstations
        output = chain.invoke(dict(topic='animals'))
        print(type(output))
        print(output)
        print(f"Total Tokens: {cb.total_tokens}")
        print(f"Total Cost (USD): ${cb.total_cost}")
        ListResponseModel.parse_obj(output)