Files
langgraph/examples/draft-revise-loop.py
T
2023-10-23 10:39:37 +01:00

141 lines
3.8 KiB
Python

from __future__ import annotations
from langchain.chat_models.openai import ChatOpenAI
from langchain.output_parsers.openai_functions import JsonOutputFunctionsParser
from langchain.prompts import SystemMessagePromptTemplate
from langchain.schema.output_parser import StrOutputParser
from permchain import Pregel, channels
# prompts
drafter_prompt = (
SystemMessagePromptTemplate.from_template(
"You are an expert on turtles, who likes to write in pirate-speak. You have been tasked by your editor with drafting a 100-word article answering the following question."
)
+ "Question:\n\n{question}"
)
reviser_prompt = (
SystemMessagePromptTemplate.from_template(
"You are an expert on turtles. You have been tasked by your editor with revising the following draft, which was written by a non-expert. You may follow the editor's notes or not, as you see fit."
)
+ "Draft:\n\n{draft}"
+ "Editor's notes:\n\n{notes}"
)
editor_prompt = (
SystemMessagePromptTemplate.from_template(
"You are an editor. You have been tasked with editing the following draft, which was written by a non-expert. Please accept the draft if it is good enough to publish, or send it for revision, along with your notes to guide the revision."
)
+ "Draft:\n\n{draft}"
)
editor_functions = [
{
"name": "revise",
"description": "Sends the draft for revision",
"parameters": {
"type": "object",
"properties": {
"notes": {
"type": "string",
"description": "The editor's notes to guide the revision.",
},
},
},
},
{
"name": "accept",
"description": "Accepts the draft",
"parameters": {
"type": "object",
"properties": {"ready": {"const": True}},
},
},
]
# llms
gpt3 = ChatOpenAI(model="gpt-3.5-turbo")
gpt4 = ChatOpenAI(model="gpt-4")
# chains
drafter_chain = drafter_prompt | gpt3 | StrOutputParser()
editor_chain = (
editor_prompt
| gpt4.bind(functions=editor_functions)
| JsonOutputFunctionsParser(args_only=False)
)
reviser_chain = reviser_prompt | gpt3 | StrOutputParser()
# application
drafter = (
# subscribe to question channel as a dict with a single key, "question"
Pregel.subscribe_to(["question"])
| drafter_chain
| Pregel.write_to("draft")
)
editor = (
# subscribe to draft channel as a dict with a single key, "draft"
Pregel.subscribe_to(["draft"])
| editor_chain
| Pregel.write_to(
# send to "notes" channel if the editor does not accept the draft
notes=lambda x: x["arguments"]["notes"]
if x["name"] == "revise"
else None
)
)
reviser = (
# subscribe to new values of "notes" channel,
# and join them with the input value (question) and "draft"
Pregel.subscribe_to(["notes"]).join(["question", "draft"])
| reviser_chain
| Pregel.write_to("draft")
)
draft_revise_loop = Pregel(
channels={
"question": channels.LastValue(str),
"draft": channels.LastValue(str),
"notes": channels.LastValue(str),
},
chains={
"drafter": drafter,
"editor": editor,
"reviser": reviser,
},
# input will be a dict with a single key, "question"
input=["question"],
# output will be a dict with keys "draft" and "notes"
output=["draft", "notes"],
# debug logging
debug=True,
)
# run
for draft in draft_revise_loop.stream({"question": "What food do turtles eat?"}):
print(draft)
print("---")
async def main():
async for draft in draft_revise_loop.astream(
{"question": "What food do turtles eat?"}
):
print(draft)
print("---")
# import asyncio
# asyncio.run(main())