Storm example contains outdated check for END in stream output

[csellis]

Checked other resources

• I added a very descriptive title to this issue.
• I searched the LangChain documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain rather than my code.

Example Code

from typing_extensions import TypedDict
class ResearchState(TypedDict):
    
    topic: str
    # outline: Outline
    # editors: List[Editor]
    # interview_results: List[InterviewState]
    # # The final sections output
    # sections: List[WikiSection]
    # article: str

import asyncio
from langgraph.graph import StateGraph, END
from IPython.display import Image


async def initialize_research(state: ResearchState):
    print("initialize_research")
    return {
        **state,
    }


async def conduct_interviews(state: ResearchState):
    print("conduct_interview")
    return {
        **state,
    }


async def refine_outline(state: ResearchState):
    print("refine_outline")
    return {
        **state,
    }


async def index_references(state: ResearchState):
    print("index_references")
    return {
        **state,
    }


async def write_sections(state: ResearchState):
    print("write_sections")
    return {
        **state,
    }


async def write_article(state: ResearchState):
    print("write_article")
    return {
        **state,
    }

builder_of_storm = StateGraph(ResearchState)

nodes = [
    ("init_research", initialize_research),
    ("conduct_interviews", conduct_interviews),
    ("refine_outline", refine_outline),
    ("index_references", index_references),
    ("write_sections", write_sections),
    ("write_article", write_article),
]
for i in range(len(nodes)):
    name, node = nodes[i]
    builder_of_storm.add_node(name, node)
    if i > 0:
        builder_of_storm.add_edge(nodes[i - 1][0], name)

builder_of_storm.set_entry_point(nodes[0][0])
builder_of_storm.set_finish_point(nodes[-1][0])
storm = builder_of_storm.compile()

Image(storm.get_graph().draw_png())


async for step in storm.astream(
    {
        "topic": "Practical processes for implementing ORPO. ORPO: Monolithic Preference Optimization without Reference Model found at https://arxiv.org/abs/2403.07691",
    }
):
    name = next(iter(step))
    print(name)
    print("-- ", str(step[name])[:300])
    if END in step:
        results = step

print(results)

Error Message and Stack Trace (if applicable)

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In[9], line 92
     89     if END in step:
     90         results = step
---> 92 print(results)

NameError: name 'results' is not defined

Description

I am trying to go through the Storm tutorial and the END is not being run. I verified the conditions were satisfied and threw END up front but still couldn't catch the condition. It is processing through the graph according to LangSmith.

This proof of concept shows that although the endpoint is set in the Graph, it's not being reached when specifically set with set_finish_point

System Info

langchain==0.1.16
langchain-anthropic==0.1.11
langchain-community==0.0.34
langchain-core==0.1.46
langchain-fireworks==0.1.2
langchain-openai==0.1.4
langchain-text-splitters==0.0.1
langchainhub==0.1.15

[hinthornw]

Ah I think this is caused by removing the __end__ from the stream outputs by default in a recent change

[SruthiDevarachetty]

How do you capture the final_step in this case as end is not being streamed?

[hinthornw]

Do you want just the update returned in that last step?

You can just remember the last value in the loop:

last_update = None
for event in graph.stream(..., stream_mode="updates'):
    last_update = event

[deanchanter]

This worked for me the tutorials will need to be updated to reflect this change. Is there a way to create the end or that that no longer best practice?

Do you want just the update returned in that last step?

You can just remember the last value in the loop:

last_update = None
for event in graph.stream(..., stream_mode="updates'):
    last_update = event