167 lines
6.2 KiB
Python
167 lines
6.2 KiB
Python
import os
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from config import OPENAI_API_KEY,LANGCHAIN_API_KEY
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from langchain_openai import ChatOpenAI
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from langchain.tools import tool
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from langchain_core.messages import HumanMessage, SystemMessage
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from langgraph.graph import StateGraph, MessagesState, START, END
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from langgraph.prebuilt import ToolNode
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from typing import TypedDict # 定义数据类型
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from typing import Annotated # 注释说明细节
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from langgraph.graph.message import add_messages
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# LangSmith调试
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os.environ["LANGCHAIN_TRACING_V2"] = "true" # 总开关，决定启用追踪功能
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os.environ["LANGCHAIN_PROJECT"] = "multi_agent_orchestration" # 自定义项目名
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os.environ["LANGCHAIN_API_KEY"] = LANGCHAIN_API_KEY
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# llm配置
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llm = ChatOpenAI(
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model="deepseek-chat",
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api_key=OPENAI_API_KEY,
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base_url="https://api.deepseek.com"
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)
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# 模拟工具
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@tool
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def search_internal_docs(query:str):
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"""搜索公司内部文档获取政策信息"""
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return "根据公司手册，年假为15天"
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@tool
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def search_web(query:str):
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"""通过搜索引擎获取最新的公开信息"""
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return "据TechCrunch报道，LangGraph 0.6已支持持久化记忆"
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@tool
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def generate_code(requirement:str):
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"""根据需求生成可运行的Python代码"""
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return "python\nprint('Hello from Code writer!')"
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# 共享状态定义
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class AgentState(TypedDict):
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messages: Annotated[list,add_messages] # 自动累积对话历史
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next_speaker: str
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# 专家节点
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def rag_expert(state:AgentState):
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prompt = "你是公司知识库专家，只基于内部文档回答问题。回答应简洁明了，直接给出最终结论。请在回答的最后一行加上：(任务已完成)"
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messages = [SystemMessage(content=prompt)]+state['messages']
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tools = [search_internal_docs]
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response = llm.bind_tools(tools).invoke(messages)
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return {'messages':[response]}
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def web_research(state:AgentState):
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prompt = "你是互联网研究员，擅长用搜索引擎获取最新公开信息。回答应简洁明了，直接给出最终结论。请在回答的最后一行加上：(任务已完成)"
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messages = [SystemMessage(content=prompt)]+state['messages']
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tools = [search_web]
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response = llm.bind_tools(tools).invoke(messages)
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return {'messages':[response]}
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def code_writer(state:AgentState):
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prompt = "你是python工程师，只生成可运行代码，不解释。回答应简洁明了，直接给出最终结论。请在回答的最后一行加上：(任务已完成)"
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messages = [SystemMessage(content=prompt)]+state['messages']
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tools = [generate_code]
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response = llm.bind_tools(tools).invoke(messages)
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return {'messages':[response]}
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# 总控节点
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def supervisor(state:AgentState):
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supervisor_prompt = """
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你是一个任务协调员。你的目标是管理专家来解决用户的问题。
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当前对话需要以下专家参与：
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- rag_expert：涉及公司政策、内部流程
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- web_research：涉及外部新闻、公开数据
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- code_writer：需要生成代码
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【决策逻辑】
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1. **检查历史记录**：先看上一个回复是否已经完整回答了用户的初始问题。
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2. **如果已经回答完毕**：必须输出 'FINISH'。
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3. **如果尚未回答或需要补充**：根据当前缺少的步骤，选择下一个最合适的专家。
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请只输出专家名字或 'FINISH'，不要输出任何其他解释。
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"""
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messages = [SystemMessage(content=supervisor_prompt)]+state['messages']
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response = llm.invoke(messages)
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next_speaker = response.content.strip()
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return {"next_speaker":next_speaker}
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# 路由函数定义
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def route_supervisor(state:AgentState):
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if state["next_speaker"]=="FINISH":
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return END
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return state["next_speaker"]
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def should_continue(state:AgentState):
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last_msg = state["messages"][-1]
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if hasattr(last_msg,"tool_calls") and last_msg.tool_calls:
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return "tools"
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return "supervisor"
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def route_after_tool(state:AgentState):
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# 工具执行完后，通过next_speaker知道是谁调用的，路由回去
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return state["next_speaker"]
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# 添加工具节点
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tools = [search_internal_docs,search_web,generate_code]
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tool_node = ToolNode(tools)
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# 构建协作图
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workflow = StateGraph(AgentState)
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# 1. 添加节点
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workflow.add_node("supervisor",supervisor)
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workflow.add_node("rag_expert",rag_expert)
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workflow.add_node("web_research",web_research)
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workflow.add_node("code_writer",code_writer)
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workflow.add_node("tools",tool_node)
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# 2. 总控回路
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workflow.add_edge(START,"supervisor")
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workflow.add_conditional_edges("supervisor",route_supervisor)
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# 3. 专家节点的ReAct循环
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for member in ["rag_expert","web_research","code_writer"]: # 为每个专家添加条件边：决定是去执行工具还是回总控
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workflow.add_conditional_edges(
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member,
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should_continue,
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{"tools":"tools","supervisor":"supervisor"}
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)
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# 4.工具节点闭环
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workflow.add_conditional_edges( # 工具执行完，根据next_speaker路由回原来的专家
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"tools",
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route_after_tool
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)
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app = workflow.compile()
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# 测试运行
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if __name__ == '__main__':
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user_input = "公司年假多少天"
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print("用户提问:",user_input)
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print('\n开始多智能体协作...\n')
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inputs = {"messages":[HumanMessage(content=user_input)]}
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# app是编译好的图，stream()会让图开始运转，并返回一个生成器
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# 图每执行完一个节点，就会产出一个step字典
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for step in app.stream(inputs):
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# 因为step是个字典，所以需要拆包拿到 节点名(Node) 与 输出内容(output)
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for node,output in step.items():
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# 有工具/专家回复
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if "messages" in output:
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msg = output["messages"][-1]
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if hasattr(msg,"tool_calls") and msg.tool_calls:
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call = msg.tool_calls[0]
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print(f"【{node}】调用工具 {call['name']}({call['args']})")
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else:
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print(f"【{node}】回复：{msg.content}")
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# supervisor刚做完决策，确定下个发言人
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elif "next_speaker" in output:
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speaker = output["next_speaker"]
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print(f"【Supervisor】指定下一位发言人：{speaker}") |