mirror of
https://github.com/langchain-ai/langgraph.git
synced 2026-09-05 09:17:47 +02:00
Nuno CamposandGitHub
f8b053a286
* Enable raising Interrupt from inside a node, add list of current interrupts to get_state * Lint * Allow multiple interrupt values in exception * Better typings * Fix some tests * Fix up * Lint * Add test * Lint * WIP stay=True * Fix tests for get_state * Remove ids * Fix step count * 999 * less fun * Undo * Update debug interface * Remove ability to pass multiple values * Undo
105 lines
3.2 KiB
Python
105 lines
3.2 KiB
Python
from dataclasses import dataclass
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from typing import Any, Literal
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INPUT = "__input__"
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CONFIG_KEY_SEND = "__pregel_send"
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CONFIG_KEY_READ = "__pregel_read"
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CONFIG_KEY_CHECKPOINTER = "__pregel_checkpointer"
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CONFIG_KEY_RESUMING = "__pregel_resuming"
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CONFIG_KEY_TASK_ID = "__pregel_task_id"
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INTERRUPT = "__interrupt__"
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ERROR = "__error__"
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TASKS = "__pregel_tasks"
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RESERVED = {
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INTERRUPT,
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ERROR,
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TASKS,
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CONFIG_KEY_SEND,
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CONFIG_KEY_READ,
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CONFIG_KEY_CHECKPOINTER,
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CONFIG_KEY_RESUMING,
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CONFIG_KEY_TASK_ID,
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INPUT,
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}
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TAG_HIDDEN = "langsmith:hidden"
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START = "__start__"
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END = "__end__"
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CHECKPOINT_NAMESPACE_SEPARATOR = "|"
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class Send:
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"""A message or packet to send to a specific node in the graph.
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The `Send` class is used within a `StateGraph`'s conditional edges to
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dynamically invoke a node with a custom state at the next step.
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Importantly, the sent state can differ from the core graph's state,
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allowing for flexible and dynamic workflow management.
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One such example is a "map-reduce" workflow where your graph invokes
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the same node multiple times in parallel with different states,
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before aggregating the results back into the main graph's state.
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Attributes:
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node (str): The name of the target node to send the message to.
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arg (Any): The state or message to send to the target node.
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Examples:
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>>> from typing import Annotated
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>>> import operator
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>>> class OverallState(TypedDict):
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... subjects: list[str]
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... jokes: Annotated[list[str], operator.add]
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...
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>>> from langgraph.constants import Send
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>>> from langgraph.graph import END, START
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>>> def continue_to_jokes(state: OverallState):
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... return [Send("generate_joke", {"subject": s}) for s in state['subjects']]
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...
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>>> from langgraph.graph import StateGraph
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>>> builder = StateGraph(OverallState)
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>>> builder.add_node("generate_joke", lambda state: {"jokes": [f"Joke about {state['subject']}"]})
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>>> builder.add_conditional_edges(START, continue_to_jokes)
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>>> builder.add_edge("generate_joke", END)
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>>> graph = builder.compile()
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>>>
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>>> # Invoking with two subjects results in a generated joke for each
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>>> graph.invoke({"subjects": ["cats", "dogs"]})
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{'subjects': ['cats', 'dogs'], 'jokes': ['Joke about cats', 'Joke about dogs']}
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"""
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node: str
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arg: Any
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def __init__(self, /, node: str, arg: Any) -> None:
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"""
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Initialize a new instance of the Send class.
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Args:
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node (str): The name of the target node to send the message to.
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arg (Any): The state or message to send to the target node.
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"""
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self.node = node
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self.arg = arg
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def __hash__(self) -> int:
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return hash((self.node, self.arg))
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def __repr__(self) -> str:
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return f"Send(node={self.node!r}, arg={self.arg!r})"
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def __eq__(self, value: object) -> bool:
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return (
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isinstance(value, Send)
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and self.node == value.node
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and self.arg == value.arg
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)
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@dataclass
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class Interrupt:
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when: Literal["before", "during", "after"]
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value: Any = None
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