LangChain入门

文章目录背景Who are youHistory Session流式输出背景将qwen3作为LLMWho are youdefmain():history{messages:[]}whileTrue:qinput(你说: )hmHumanMessage(q)history[messages].append(hm)print(AI:)historyagent.invoke(history)last_messagehistory[messages][-1]ifisinstance(last_message,AIMessage):print(last_message.content)modelinit_chat_model(modelconfig.model_name,api_keyconfig.api_key,base_urlconfig.base_url,model_provideropenai)agentcreate_agent(modelmodel)if__name____main__:main()History Sessiondefmain():whileTrue:qinput(你说: )hmHumanMessage(q)history{messages:[hm]}print(AI:)# thread id算是session的唯一标识。langchain会帮我们记住historyrespagent.invoke(history,{configurable:{thread_id:1}})print(resp[messages][-1].content)modelinit_chat_model(modelconfig.model_name,api_keyconfig.api_key,base_urlconfig.base_url,model_provideropenai)agentcreate_agent(modelmodel,checkpointerInMemorySaver())if__name____main__:main()流式输出defmain():whileTrue:qinput(你说: )hmHumanMessage(q)history{messages:[hm]}print(AI:,end,flushTrue)fortoken,messagesinagent.stream(history,configRunnableConfig(configurable{thread_id:aaa}),stream_modemessages):ifisinstance(token,AIMessageChunk):print(token.content,end,flushTrue)print()modelinit_chat_model(modelconfig.model_name,api_keyconfig.api_key,base_urlconfig.base_url,model_provideropenai)withSqliteSaver.from_conn_string(checkpoints.db3)ascheckpointer:checkpointer.setup()agentcreate_agent(modelmodel,middleware[SummarizationMiddleware(modelmodel,trigger(tokens,1000),keep(messages,20))],checkpointercheckpointer)if__name____main__:main()