118 lines
3.6 KiB
Python
118 lines
3.6 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
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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 langgraph.checkpoint.memory import MemorySaver
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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"] = "human_approval" # 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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# 定义一个敏感工具:发送邮件(模拟)
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@tool
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def send_email(to, content):
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"""模拟发送邮件"""
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return f'邮件已发送至{to},内容为:{content}'
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# 工具绑定到llm
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tools = [send_email]
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llm_with_tools = llm.bind_tools(tools)
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# Node函数与Edge节点
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tool_node = ToolNode(tools)
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def call_model(state: MessagesState):
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response = llm_with_tools.invoke(state['messages'])
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return {"messages":[response]}
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def should_continue(state: MessagesState):
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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 END
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# 构建基础ReAct图
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workflow = StateGraph(MessagesState)
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workflow.add_node("agent", call_model)
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workflow.add_node("tools", tool_node)
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workflow.add_edge(START, "agent")
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workflow.add_conditional_edges(
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"agent",
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should_continue,
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{
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"tools": "tools",
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END: END
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}
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)
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workflow.add_edge("tools", "agent")
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app = workflow.compile(
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# 在内存里做状态持久化
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checkpointer=MemorySaver(),
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interrupt_before=["tools"] # 选择要人工审批的节点 -- 负责在哪里停,之后的代码负责停了之后怎么办
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)
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if __name__ == '__main__':
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config = {
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"configurable":{"thread_id":"user123"}
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}
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user_input = "请帮我给 boss@example.com 发一封邮件,内容是:会议推迟到明天下午3点。不要询问其他细节。"
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print("用户输入:",user_input)
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print("\nAgent正在思考...\n")
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# 初识输入
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inputs = {"messages":[HumanMessage(content=user_input)]}
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while 1:
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# 触发工作流执行,推进到下一个中断点或自然结束
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# inputs注入事件;config确定回话id;"values":完整记录每步结果
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for _ in app.stream(inputs,config,stream_mode="values"): # 流式执行
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pass # 必须迭代生成器,才能实际执行工作流
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# 获取当前状态
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snapshot = app.get_state(config)
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next_tasks = snapshot.next # 返回下一步要执行的节点名列表
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# 如果没有下一步,说明工作流已结束
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if not next_tasks:
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final_msg = snapshot.values['messages'][-1]
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print(f'\n最终回复:{final_msg.content}')
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break
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# 如果下一步是需要审批的节点
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if "tools" in next_tasks:
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last_msg = snapshot.values['messages'][-1]
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tool_call = last_msg.tool_calls[0]
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print(f'\n⚠️ Agent准备执行操作:')
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print(f' 工具名称:{tool_call["name"]}')
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print(f' 参数:{tool_call["args"]}')
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approval = input("\n✅ 是否批准执行?(输入 'yes' 继续,其他取消): ").strip().lower()
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if approval == "yes":
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print('\n 继续执行...')
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inputs = None # 表示从断点继续,无新输入
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else:
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print("\n❌ 操作已取消,流程终止")
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break |