{"id":740,"date":"2026-07-16T14:19:47","date_gmt":"2026-07-16T06:19:47","guid":{"rendered":"https:\/\/larkdrop.cafe\/?p=740"},"modified":"2026-07-16T14:19:48","modified_gmt":"2026-07-16T06:19:48","slug":"langchain","status":"publish","type":"post","link":"https:\/\/larkdrop.cafe\/index.php\/2026\/07\/16\/langchain\/","title":{"rendered":"LangChain"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">LangChain \u7b80\u4ecb<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">LangChain \u662f\u4e00\u4e2a\u7528\u4e8e\u5f00\u53d1\u5927\u8bed\u8a00\u6a21\u578b\u5e94\u7528\u7684\u6846\u67b6\u3002\u5b83\u63d0\u4f9b\u4e86\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7edf\u4e00\u7684\u6a21\u578b\u8c03\u7528\u63a5\u53e3\uff08\u652f\u6301 OpenAI\u3001\u901a\u4e49\u5343\u95ee\u7b49\u591a\u79cd\u6a21\u578b\uff09<\/li>\n\n\n\n<li>\u63d0\u793a\u8bcd\u6a21\u677f\u7ba1\u7406<\/li>\n\n\n\n<li>\u4f1a\u8bdd\u8bb0\u5fc6\u7ba1\u7406<\/li>\n\n\n\n<li>\u5de5\u5177\u8c03\u7528\u652f\u6301<\/li>\n\n\n\n<li>\u6587\u6863\u52a0\u8f7d\u3001\u5207\u5206\u3001\u5411\u91cf\u68c0\u7d22\uff08RAG\uff09\u652f\u6301<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b89\u88c5\u4f9d\u8d56\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\npip install langchain-core langchain-openai langchain-community redis\n```<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e00\u8f6e\u5bf9\u8bdd<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u91c7\u53d6\u5faa\u5e8f\u6e10\u8fdb\u7684\u65b9\u5f0f\u8bb2\u89e3 LangChain\uff0c\u5148\u4ece\u6700\u7b80\u5355\u7684\u4e00\u8f6e\u5bf9\u8bdd\u5f00\u59cb\uff0c\u9010\u6b65\u589e\u5f3a\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u6700\u57fa\u672c\u7684\u4e00\u8f6e\u5bf9\u8bdd<\/li>\n\n\n\n<li>\u589e\u52a0\u7cfb\u7edf\u63d0\u793a\u8bcd<\/li>\n\n\n\n<li>\u589e\u52a0\u5de5\u5177\u8c03\u7528<\/li>\n\n\n\n<li>\u7ed3\u6784\u5316\u8f93\u51fa<\/li>\n\n\n\n<li>\u5b9e\u73b0\u6d41\u5f0f\u8f93\u51fa<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">\u6700\u57fa\u672c\u7684\u4e00\u8f6e\u5bf9\u8bdd<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u573a\u666f\uff1a\u7528\u6237\u8f93\u5165\u4e00\u4e2a\u95ee\u9898\uff0c\u6a21\u578b\u7ed9\u51fa\u56de\u7b54\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import ChatOpenAI\n\n# \u521b\u5efa\u6a21\u578b\u5ba2\u6237\u7aef\n# ChatOpenAI \u662f LangChain \u5bf9 OpenAI \u517c\u5bb9\u63a5\u53e3\u7684\u5c01\u88c5\n# \u901a\u4e49\u5343\u95ee\u63d0\u4f9b\u4e86 OpenAI \u517c\u5bb9\u7684\u63a5\u53e3\uff0c\u6240\u4ee5\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\nllm = ChatOpenAI(\n    model=\"qwen-plus\",                                          # \u6a21\u578b\u540d\u79f0\n    api_key=\"\u4f60\u7684API Key\",                                      # API\u5bc6\u94a5\n    base_url=\"https:\/\/dashscope.aliyuncs.com\/compatible-mode\/v1\",  # \u63a5\u53e3\u5730\u5740\n)\n\n# \u53d1\u9001\u6d88\u606f\u5e76\u83b7\u53d6\u56de\u7b54\n#\nresponse = llm.invoke(\"\u4f60\u597d\uff0c\u8bf7\u7b80\u5355\u4ecb\u7ecd\u4e00\u4e0b\u4f60\u81ea\u5df1\")\n\n# response \u662f\u4e00\u4e2a AIMessage \u5bf9\u8c61\uff0c\u5176content\u5c5e\u6027\u5c31\u662f\u56de\u590d\u7684\u5b57\u7b26\u4e32\u5185\u5bb9\nprint(response.content)\n```<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u589e\u52a0\u7cfb\u7edf\u63d0\u793a\u8bcd\u548c\u7528\u6237\u63d0\u793a\u8bcd<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u5e0c\u671b\u901a\u8fc7\u7cfb\u7edf\u63d0\u793a\u8bcd\u6307\u5b9a\u6a21\u578b\u626e\u6f14\u67d0\u4e2a\u89d2\u8272\u6765\u56de\u7b54\u95ee\u9898\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import ChatOpenAI\nfrom langchain_core.prompts import ChatPromptTemplate\n\nllm = ChatOpenAI(\n    model=\"qwen-plus\",\n    api_key=\"\u4f60\u7684API Key\",\n    base_url=\"https:\/\/dashscope.aliyuncs.com\/compatible-mode\/v1\",\n)\n\n# \u5b9a\u4e49\u63d0\u793a\u8bcd\u6a21\u677f\n# system: \u7cfb\u7edf\u63d0\u793a\u8bcd\uff0c\u5b9a\u4e49\u6a21\u578b\u7684\u89d2\u8272\u548c\u884c\u4e3a\u8fb9\u754c\n# human: \u7528\u6237\u8f93\u5165\u7684\u6d88\u606f\uff0c{question} \u662f\u5360\u4f4d\u7b26\nprompt = ChatPromptTemplate.from_messages([\n    (\"system\", \"\u4f60\u662f\u4e00\u4f4d\u4e13\u4e1a\u7684\u5ba2\u670d\u52a9\u624b\uff0c\u8bf7\u8010\u5fc3\u3001\u793c\u8c8c\u5730\u56de\u7b54\u7528\u6237\u95ee\u9898\u3002\"),\n    (\"human\", \"{question}\"),\n])\n\n# \u4f7f\u7528prompt\u683c\u5f0f\u5316\u6d88\u606f\uff0c\u518d\u4f20\u7ed9\u6a21\u578b\nmessages = prompt.invoke({\"question\": \"\u4f60\u4eec\u7684\u9000\u8d27\u653f\u7b56\u662f\u4ec0\u4e48\uff1f\"})\nresponse = llm.invoke(messages)\nprint(response.content)\n```<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u589e\u52a0\u5de5\u5177\u8c03\u7528<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u6a21\u578b\u56de\u7b54\u9700\u8981\u4f9d\u8d56<strong>\u5916\u90e8\u4fe1\u606f<\/strong>\u65f6\uff08\u6bd4\u5982\u67e5\u5929\u6c14\u3001\u67e5\u6570\u636e\u5e93\u3001\u8c03\u7528API\uff09\uff0c\u6211\u4eec\u53ef\u4ee5\u7ed9\u6a21\u578b\u63d0\u4f9b\u5de5\u5177\uff0c\u8ba9\u5b83\u5728\u9700\u8981\u65f6\u8c03\u7528\u5de5\u5177\u62ff\u5230\u6570\u636e\u518d\u56de\u7b54\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\u7528\u4e00\u4e2a<strong>\u5929\u6c14\u67e5\u8be2<\/strong>\u7684\u4f8b\u5b50\uff0c\u6f14\u793a\u5de5\u5177\u8c03\u7528\u7684\u5b8c\u6574\u95ed\u73af\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5b8c\u6574\u6d41\u7a0b\uff1a<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5b9a\u4e49\u5de5\u5177 + \u628a\u5de5\u5177\u7ed1\u5b9a\u5230\u6a21\u578b<\/li>\n\n\n\n<li>\u628a\u7528\u6237\u95ee\u9898\u53d1\u7ed9\u6a21\u578b<\/li>\n\n\n\n<li>\u6a21\u578b\u5224\u65ad\u9700\u8981\u8c03\u7528\u5de5\u5177 \u2192 \u8fd4\u56de\u5de5\u5177\u8c03\u7528\u8bf7\u6c42\uff08\u4e0d\u662f\u6700\u7ec8\u7b54\u6848\uff09<\/li>\n\n\n\n<li>\u6211\u4eec\u6267\u884c\u5de5\u5177\u51fd\u6570\uff0c\u62ff\u5230\u7ed3\u679c<\/li>\n\n\n\n<li>\u628a\u5de5\u5177\u7ed3\u679c\u4f5c\u4e3a\u00a0<code>ToolMessage<\/code>\u00a0\u56de\u4f20\u7ed9\u6a21\u578b<\/li>\n\n\n\n<li>\u6a21\u578b\u6839\u636e\u5de5\u5177\u7ed3\u679c\u751f\u6210\u6700\u7ec8\u7684\u81ea\u7136\u8bed\u8a00\u56de\u7b54<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import ChatOpenAI\nfrom langchain_core.tools import tool\nfrom langchain_core.messages import HumanMessage, ToolMessage\nfrom pydantic import BaseModel, Field\n\n# ============ 1. \u5b9a\u4e49\u5de5\u5177 ============\n\nclass GetWeatherArgs(BaseModel):\n    \"\"\"\u5de5\u5177\u7684\u53c2\u6570\u6a21\u578b\uff08\u7c7b\u6bd4Java\u4e2d\u7684DTO\uff09\"\"\"\n    city: str = Field(description=\"\u57ce\u5e02\u540d\u79f0\uff0c\u4f8b\u5982\uff1a\u5317\u4eac\u3001\u4e0a\u6d77\")\n\n@tool(\"get_weather\", args_schema=GetWeatherArgs)\ndef get_weather(city: str) -&gt; str:\n    \"\"\"\u67e5\u8be2\u6307\u5b9a\u57ce\u5e02\u7684\u5b9e\u65f6\u5929\u6c14\u3002\u5f53\u7528\u6237\u8be2\u95ee\u67d0\u4e2a\u57ce\u5e02\u7684\u5929\u6c14\u65f6\u8c03\u7528\u3002\"\"\"\n    # \u8fd9\u91cc\u6a21\u62df\u4e00\u4e2a\u5929\u6c14\u6570\u636e\uff08\u5b9e\u9645\u9879\u76ee\u4e2d\u4f1a\u8c03\u7528\u771f\u5b9e\u7684\u5929\u6c14API\uff09\n    fake_data = {\n        \"\u5317\u4eac\": \"\u6674\uff0c22\u00b0C\uff0c\u4e1c\u5357\u98ce3\u7ea7\",\n        \"\u4e0a\u6d77\": \"\u591a\u4e91\uff0c25\u00b0C\uff0c\u65e0\u98ce\",\n        \"\u676d\u5dde\": \"\u5c0f\u96e8\uff0c20\u00b0C\uff0c\u5357\u98ce2\u7ea7\",\n    }\n    return fake_data.get(city, f\"{city} \u6682\u65e0\u5929\u6c14\u6570\u636e\")\n\n# ============ 2. \u7ed1\u5b9a\u5de5\u5177\u5230\u6a21\u578b ============\n\nllm = ChatOpenAI(\n    model=\"qwen-plus\",\n    api_key=\"\u4f60\u7684API Key\",\n    base_url=\"https:\/\/dashscope.aliyuncs.com\/compatible-mode\/v1\",\n)\n# bind_tools \u544a\u8bc9\u6a21\u578b\uff1a\u4f60\u6709\u8fd9\u4e9b\u5de5\u5177\u53ef\u4ee5\u8c03\u7528\nllm_with_tools = llm.bind_tools([get_weather])\n\n# ============ 3. \u7b2c\u4e00\u6b21\u8c03\u7528\u6a21\u578b ============\n\n# \u7ef4\u62a4\u4e00\u4e2a\u6d88\u606f\u5217\u8868\uff0c\u8bb0\u5f55\u5bf9\u8bdd\u8fc7\u7a0b\uff08\u540e\u7eed\u8981\u628a\u5de5\u5177\u7ed3\u679c\u8ffd\u52a0\u8fdb\u53bb\uff09\nmessages = [HumanMessage(content=\"\u5317\u4eac\u4eca\u5929\u5929\u6c14\u600e\u4e48\u6837\uff1f\")]\nresponse = llm_with_tools.invoke(messages)\n\n# \u6a21\u578b\u4e0d\u4f1a\u76f4\u63a5\u56de\u7b54\uff0c\u800c\u662f\u8fd4\u56de\u4e00\u4e2a\"\u6211\u8981\u8c03\u7528\u5de5\u5177\"\u7684\u8bf7\u6c42\n# response.content \u901a\u5e38\u4e3a\u7a7a\u5b57\u7b26\u4e32\n# response.tool_calls \u5305\u542b\u8981\u8c03\u7528\u7684\u5de5\u5177\u4fe1\u606f\nprint(response.tool_calls)\n# [{'name': 'get_weather', 'args': {'city': '\u5317\u4eac'}, 'id': 'call_xxx'}]\n\n# \u628a\u6a21\u578b\u7684\u8fd9\u4e2a\"\u5de5\u5177\u8c03\u7528\u8bf7\u6c42\"\u4e5f\u52a0\u5165\u5230\u6d88\u606f\u5217\u8868\nmessages.append(response)\n\n# ============ 4. \u6267\u884c\u5de5\u5177 ============\n\n# \u904d\u5386\u6a21\u578b\u8981\u6c42\u8c03\u7528\u7684\u6240\u6709\u5de5\u5177\nfor tool_call in response.tool_calls:\n    # \u53d6\u51fa\u5de5\u5177\u540d\u548c\u53c2\u6570\n    tool_name = tool_call[\"name\"]\n    tool_args = tool_call[\"args\"]\n\n    # \u6267\u884c\u5de5\u5177\u51fd\u6570\uff08\u8fd9\u91cc\u6211\u4eec\u53ea\u7ed1\u5b9a\u4e86\u4e00\u4e2a\u5de5\u5177\uff0c\u76f4\u63a5\u8c03\u7528\uff09\n    if tool_name == \"get_weather\":\n        tool_result = get_weather.invoke(tool_args)  # \"\u6674\uff0c22\u00b0C\uff0c\u4e1c\u5357\u98ce3\u7ea7\"\n\n    # ============ 5. \u628a\u5de5\u5177\u7ed3\u679c\u4f5c\u4e3aToolMessage\u56de\u4f20\u7ed9\u6a21\u578b ============\n    # ToolMessage \u5fc5\u987b\u901a\u8fc7 tool_call_id \u5173\u8054\u5230\u5bf9\u5e94\u7684\u5de5\u5177\u8c03\u7528\u8bf7\u6c42\n    messages.append(ToolMessage(content=tool_result, tool_call_id=tool_call[\"id\"]))\n\n# ============ 6. \u7b2c\u4e8c\u6b21\u8c03\u7528\u6a21\u578b\uff0c\u8ba9\u5b83\u57fa\u4e8e\u5de5\u5177\u7ed3\u679c\u751f\u6210\u6700\u7ec8\u56de\u7b54 ============\n\nfinal_response = llm_with_tools.invoke(messages)\nprint(final_response.content)\n# \u8f93\u51fa\u7c7b\u4f3c\uff1a\"\u5317\u4eac\u4eca\u5929\u5929\u6c14\u6674\u6717\uff0c\u6c14\u6e2922\u00b0C\uff0c\u4e1c\u5357\u98ce3\u7ea7\uff0c\u662f\u4e2a\u4e0d\u9519\u7684\u5929\u6c14\u3002\"\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5173\u952e\u70b9\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5de5\u5177\u8c03\u7528\u662f<strong>\u4e24\u6b21LLM\u8c03\u7528<\/strong>\uff1a\u7b2c\u4e00\u6b21\u8ba9\u6a21\u578b\u51b3\u5b9a\u8981\u4e0d\u8981\u8c03\u7528\u5de5\u5177\uff0c\u7b2c\u4e8c\u6b21\u8ba9\u6a21\u578b\u6839\u636e\u5de5\u5177\u7ed3\u679c\u751f\u6210\u6700\u7ec8\u56de\u7b54<\/li>\n\n\n\n<li>\u4e2d\u95f4\u7684\u00a0<code>ToolMessage<\/code>\u00a0\u5fc5\u987b\u7528\u00a0<code>tool_call_id<\/code>\u00a0\u548c\u5de5\u5177\u8c03\u7528\u8bf7\u6c42\u5173\u8054\u8d77\u6765\uff0c\u6a21\u578b\u624d\u80fd\u77e5\u9053&#8221;\u8fd9\u662f\u54ea\u6b21\u5de5\u5177\u8c03\u7528\u7684\u7ed3\u679c&#8221;<\/li>\n\n\n\n<li>\u5982\u679c\u6a21\u578b\u4e00\u6b21\u8981\u8c03\u7528\u591a\u4e2a\u5de5\u5177\uff08\u6bd4\u5982\u540c\u65f6\u67e5\u5317\u4eac\u548c\u4e0a\u6d77\u7684\u5929\u6c14\uff09\uff0c\u5c31\u4f1a\u6709\u591a\u4e2a\u00a0<code>tool_call<\/code>\uff0c\u9700\u8981\u5168\u90e8\u6267\u884c\u540e\u518d\u56de\u4f20<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u589e\u52a0\u7ed3\u6784\u5316\u8f93\u51fa<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f88\u591a\u65f6\u5019\u6211\u4eec\u5e0c\u671b\u6a21\u578b\u8fd4\u56de\u7684\u4e0d\u662f\u4e00\u6bb5\u81ea\u7531\u7684\u6587\u672c\uff0c\u800c\u662f<strong>\u7ed3\u6784\u5316\u7684\u6570\u636e<\/strong>\uff08\u5982JSON\uff09\uff0c\u65b9\u4fbf\u540e\u7eed\u4ee3\u7801\u76f4\u63a5\u4f7f\u7528\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import ChatOpenAI\nfrom pydantic import BaseModel, Field\n\n# \u5b9a\u4e49\u8f93\u51fa\u7ed3\u6784\uff08\u7c7b\u6bd4Java\u4e2d\u7684\u54cd\u5e94DTO\uff09\nclass SentimentResult(BaseModel):\n    sentiment: str = Field(description=\"\u60c5\u611f\u503e\u5411\uff1a\u6b63\u9762\u3001\u8d1f\u9762\u3001\u4e2d\u6027\")\n    score: int = Field(description=\"\u5f3a\u70c8\u7a0b\u5ea6\uff0c1-10\u5206\")\n    keywords: list[str] = Field(description=\"\u5173\u952e\u8bcd\u5217\u8868\")\n\nllm = ChatOpenAI(\n    model=\"qwen-plus\",\n    api_key=\"\u4f60\u7684API Key\",\n    base_url=\"https:\/\/dashscope.aliyuncs.com\/compatible-mode\/v1\",\n)\n\n# with_structured_output \u8ba9\u6a21\u578b\u6309\u7167\u6307\u5b9a\u7684\u7ed3\u6784\u8fd4\u56de\u6570\u636e\nstructured_llm = llm.with_structured_output(SentimentResult)\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u6709\u4e2a\u5f88\u5bb9\u6613\u56f0\u60d1\u7684\u70b9\uff1a<strong>\u6a21\u578b\u8fd4\u56de\u7684\u4e0d\u5e94\u8be5\u662f\u5b57\u7b26\u4e32\u5417\uff1f\u4e3a\u4ec0\u4e48\u540e\u9762\u53ef\u4ee5\u76f4\u63a5\u00a0<code>result.sentiment<\/code>\u00a0\u5f53\u5bf9\u8c61\u8bbf\u95ee\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>with_structured_output(SentimentResult)<\/code>&nbsp;\u5728\u80cc\u540e\u9ed8\u9ed8\u505a\u4e86\u4e24\u4ef6\u4e8b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u544a\u8bc9\u6a21\u578b\u6309schema\u8fd4\u56deJSON<\/strong>\uff1a\u628a\u00a0<code>SentimentResult<\/code>\u00a0\u8fd9\u4e2a Pydantic \u6a21\u578b\u7684\u5b57\u6bb5\u5b9a\u4e49\uff08\u5b57\u6bb5\u540d+\u7c7b\u578b+description\uff09\u8f6c\u6362\u6210 JSON Schema\uff0c\u4f5c\u4e3a\u63d0\u793a\u8bcd\u7684\u4e00\u90e8\u5206\u53d1\u7ed9\u6a21\u578b\uff0c\u5f3a\u5236\u6a21\u578b\u8fd4\u56de\u4e25\u683c\u7b26\u5408\u8fd9\u4e2a schema \u7684 JSON<\/li>\n\n\n\n<li><strong>\u81ea\u52a8\u628aJSON\u8f6c\u6210\u5bf9\u8c61<\/strong>\uff1a\u6536\u5230\u6a21\u578b\u8fd4\u56de\u7684 JSON \u5b57\u7b26\u4e32\u540e\uff0cLangChain \u81ea\u52a8\u8c03\u7528\u00a0<code>SentimentResult(**json_data)<\/code>\uff0c\u628a JSON \u53cd\u5e8f\u5217\u5316\u4e3a Pydantic \u5bf9\u8c61<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u6240\u4ee5\u6700\u7ec8\u6211\u4eec\u62ff\u5230\u7684&nbsp;<code>result<\/code>&nbsp;\u5df2\u7ecf\u662f\u4e00\u4e2a&nbsp;<code>SentimentResult<\/code>&nbsp;\u5bf9\u8c61\u4e86\uff0c\u4e0d\u662f\u539f\u59cbJSON\u5b57\u7b26\u4e32\u3002\u8fd9\u5c31\u548cJava\u91cc\u7684Jackson\u628aJSON\u81ea\u52a8\u8f6c\u6210DTO\u5bf9\u8c61\u662f\u4e00\u56de\u4e8b\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nresult = structured_llm.invoke(\"\u8fd9\u5bb6\u9910\u5385\u7684\u83dc\u592a\u96be\u5403\u4e86\uff0c\u670d\u52a1\u4e5f\u5dee\uff0c\u518d\u4e5f\u4e0d\u6765\u4e86\")\n\n# result \u662f SentimentResult \u7c7b\u7684\u5b9e\u4f8b\uff0c\u53ef\u4ee5\u76f4\u63a5\u7528 . \u8bbf\u95ee\u5c5e\u6027\nprint(f\"\u60c5\u611f\u503e\u5411: {result.sentiment}\")    # \u8d1f\u9762\nprint(f\"\u5f3a\u70c8\u7a0b\u5ea6: {result.score}\")        # 9\nprint(f\"\u5173\u952e\u8bcd: {result.keywords}\")       # ['\u96be\u5403', '\u670d\u52a1\u5dee']\n\n# \u9a8c\u8bc1 result \u7684\u7c7b\u578b\nprint(type(result))  # &lt;class '__main__.SentimentResult'&gt;\n```<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u5b9e\u73b0\u6d41\u5f0f\u8f93\u51fa<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4ec0\u4e48\u662fSSE\uff08Server-Sent Events\uff09\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SSE\u662f\u4e00\u79cd\u670d\u52a1\u5668\u5411\u5ba2\u6237\u7aef\u5355\u5411\u63a8\u9001\u6570\u636e\u7684\u6280\u672f\u3002\u60f3\u8c61\u4e00\u4e0b\u4f60\u5728\u770b\u76f4\u64ad\u5f39\u5e55\uff0c\u5f39\u5e55\u4e0d\u662f\u4e00\u6b21\u6027\u5168\u90e8\u52a0\u8f7d\u7684\uff0c\u800c\u662f\u4e00\u6761\u4e00\u6761\u5b9e\u65f6\u63a8\u9001\u8fc7\u6765\u7684\u3002SSE\u5c31\u662f\u8fd9\u4e2a\u539f\u7406\u2014\u2014\u670d\u52a1\u5668\u53ef\u4ee5\u6301\u7eed\u4e0d\u65ad\u5730\u5411\u5ba2\u6237\u7aef\u63a8\u9001\u6570\u636e\uff0c\u800c\u4e0d\u9700\u8981\u5ba2\u6237\u7aef\u53cd\u590d\u8bf7\u6c42\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6a21\u578b\u751f\u6210\u56de\u7b54\u662f\u9010\u5b57\u9010\u53e5\u7684\uff0c\u5982\u679c\u7b49\u6a21\u578b\u5168\u90e8\u751f\u6210\u5b8c\u518d\u8fd4\u56de\uff0c\u7528\u6237\u9700\u8981\u7b49\u5f88\u4e45\u3002\u4f7f\u7528SSE\uff0c\u6a21\u578b\u6bcf\u751f\u6210\u4e00\u5c0f\u6bb5\u6587\u5b57\u5c31\u7acb\u523b\u63a8\u9001\u7ed9\u7528\u6237\uff0c\u7528\u6237\u4f53\u9a8c\u5c31\u50cf&#8221;\u6253\u5b57\u673a&#8221;\u4e00\u6837\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ce8\u610f\uff1aSSE\u5e76\u672a\u63d0\u5347\u6a21\u578b\u7684\u8f93\u51fa\u6548\u7387\uff0c\u4f46\u5b83\u53ef\u4ee5\u63d0\u5347\u7528\u6237\u4f53\u9a8c\uff0c\u8ba9\u7528\u6237\u5c3d\u5feb\u5f97\u5230\u7b2c\u4e00\u6b21\u54cd\u5e94\uff01<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8bb2\u89e3\u5982\u4f55\u5728LangChain\u4e2d\u5b9e\u73b0\u6d41\u5f0f\u8f93\u51fa\u524d\uff0c\u6211\u4eec\u5fc5\u987b\u5148\u7406\u89e3&nbsp;<strong>Python \u4e2d\u7684 yield \u5173\u952e\u5b57<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u666e\u901a\u51fd\u6570\u7528&nbsp;<code>return<\/code>&nbsp;\u8fd4\u56de\u7ed3\u679c\uff0c\u51fd\u6570\u6267\u884c\u5b8c\u5c31\u7ed3\u675f\u4e86\u3002\u800c\u4f7f\u7528&nbsp;<code>yield<\/code>&nbsp;\u7684\u51fd\u6570\u53eb\u505a<strong>\u751f\u6210\u5668\u51fd\u6570<\/strong>\uff0c\u5b83\u53ef\u4ee5&#8221;\u6682\u505c&#8221;\u6267\u884c\uff0c\u6bcf\u6b21\u8c03\u7528\u65f6\u8fd4\u56de\u4e00\u4e2a\u503c\uff0c\u4e0b\u6b21\u8c03\u7528\u65f6\u4ece\u4e0a\u6b21\u6682\u505c\u7684\u5730\u65b9\u7ee7\u7eed\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6253\u4e2a\u6bd4\u65b9\uff1a<code>return<\/code>&nbsp;\u5c31\u50cf\u4e00\u6b21\u6027\u628a\u6574\u672c\u4e66\u7ed9\u4f60\uff0c<code>yield<\/code>&nbsp;\u5c31\u50cf\u4e00\u9875\u4e00\u9875\u5730\u7ffb\u7ed9\u4f60\u770b\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u666e\u901a\u51fd\u6570\uff1a\u4e00\u6b21\u6027\u8fd4\u56de\u6240\u6709\u6570\u636e\ndef get_all_numbers():\n    return [1, 2, 3, 4, 5]\n\n# \u751f\u6210\u5668\u51fd\u6570\uff1a\u6bcf\u6b21yield\u4e00\u4e2a\u6570\u636e\ndef generate_numbers():\n    yield 1  # \u7b2c\u4e00\u6b21\u8c03\u7528\u8fd4\u56de1\uff0c\u7136\u540e\u6682\u505c\n    yield 2  # \u7b2c\u4e8c\u6b21\u8c03\u7528\u8fd4\u56de2\uff0c\u7136\u540e\u6682\u505c\n    yield 3  # \u7b2c\u4e09\u6b21\u8c03\u7528\u8fd4\u56de3\uff0c\u7136\u540e\u6682\u505c\n\n# \u4f7f\u7528\u751f\u6210\u5668\nfor num in generate_numbers():\n    print(num)  # \u4f9d\u6b21\u6253\u5370 1, 2, 3\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6d41\u5f0f\u8f93\u51fa\u7684\u5b9e\u73b0\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import ChatOpenAI\nfrom fastapi import FastAPI\nfrom fastapi.responses import StreamingResponse\nimport json\n\napp = FastAPI()\n\nllm = ChatOpenAI(\n    model=\"qwen-plus\",\n    api_key=\"\u4f60\u7684API Key\",\n    base_url=\"https:\/\/dashscope.aliyuncs.com\/compatible-mode\/v1\",\n    streaming=True,  # \u5f00\u542f\u6d41\u5f0f\u6a21\u5f0f\n)\n\n@app.post(\"\/chat\/stream\")\ndef stream_chat(message: str):\n    def event_stream():\n        # llm.stream() \u8fd4\u56de\u4e00\u4e2a\u751f\u6210\u5668\uff0c\u6bcf\u6b21yield\u4e00\u4e2a\u6587\u672c\u7247\u6bb5\n        for chunk in llm.stream(message):\n            text = chunk.content\n            if text:\n                # \u6309\u7167SSE\u683c\u5f0f\u5c01\u88c5\u6570\u636e\n                payload = json.dumps({\"type\": \"delta\", \"text\": text}, ensure_ascii=False)\n                yield f\"data: {payload}\\n\\n\"\n        # \u53d1\u9001\u7ed3\u675f\u6807\u8bb0\n        yield f\"data: {json.dumps({'type': 'done'})}\\n\\n\"\n\n    # StreamingResponse \u4f1a\u6301\u7eed\u8c03\u7528 event_stream() \u751f\u6210\u5668\n    return StreamingResponse(event_stream(), media_type=\"text\/event-stream\")\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">&#8212;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u94fe\uff08Chain\uff09<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u56de\u987e\u4e00\u4e0b\u524d\u9762&#8221;\u589e\u52a0\u7cfb\u7edf\u63d0\u793a\u8bcd&#8221;\u90a3\u4e00\u8282\u7684\u4ee3\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u666e\u901a\u5199\u6cd5\uff1a\u624b\u52a8\u8c03\u7528prompt\u683c\u5f0f\u5316\uff0c\u518d\u624b\u52a8\u8c03\u7528llm\nprompt = ChatPromptTemplate.from_messages([...])\nllm = ChatOpenAI(...)\n\n# \u5148\u683c\u5f0f\u5316\nmessages = prompt.invoke({\"question\": \"\u4f60\u597d\"})\n# \u518d\u8c03\u7528\u6a21\u578b\nresponse = llm.invoke(messages)\nprint(response.content)\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u79cd\u5199\u6cd5\u6ca1\u6709\u95ee\u9898\uff0c\u4f46\u5f53\u6b65\u9aa4\u53d8\u591a\u65f6\uff0c\u4ee3\u7801\u4f1a\u53d8\u5f97\u5197\u957f\u3002LangChain\u63d0\u4f9b\u4e86\u4e00\u79cd\u66f4\u4f18\u96c5\u7684\u5199\u6cd5\u2014\u2014<strong>\u94fe\uff08Chain\uff09<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4ec0\u4e48\u662f\u94fe\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u94fe\u5c31\u662f\u5c06\u591a\u4e2a\u5904\u7406\u6b65\u9aa4\u4e32\u8054\u8d77\u6765\u7684\u7ba1\u9053\u3002\u6bcf\u4e2a\u6b65\u9aa4\u7684\u8f93\u51fa\u4f1a\u81ea\u52a8\u6210\u4e3a\u4e0b\u4e00\u4e2a\u6b65\u9aa4\u7684\u8f93\u5165\uff0c\u6700\u7ec8\u5f97\u5230\u5904\u7406\u7ed3\u679c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u7c7b\u6bd4Java\uff1a<\/strong>&nbsp;\u94fe\u7684\u6982\u5ff5\u7c7b\u4f3c\u4e8eJava\u4e2d\u7684Stream\u6d41\u5f0f\u5904\u7406\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n\/\/ Java Stream\uff1a\u591a\u4e2a\u5904\u7406\u6b65\u9aa4\u4e32\u8054\nList&lt;String&gt; result = users.stream()\n    .filter(u -&gt; u.getAge() &gt; 18)     \/\/ \u6b65\u9aa41\uff1a\u8fc7\u6ee4\n    .map(User::getName)               \/\/ \u6b65\u9aa42\uff1a\u8f6c\u6362\n    .collect(Collectors.toList());    \/\/ \u6b65\u9aa43\uff1a\u6536\u96c6\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728LangChain\u4e2d\uff0c\u4f7f\u7528&nbsp;<code>|<\/code>&nbsp;\u7ba1\u9053\u7b26\u5c06\u7ec4\u4ef6\u4e32\u8054\u6210\u94fe\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u94fe\u7684\u5199\u6cd5\uff1a\u4e00\u884c\u4ee3\u7801\u4e32\u8054\u591a\u4e2a\u6b65\u9aa4\nchain = prompt | llm | output_parser\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5bf9\u6bd4\u666e\u901a\u5199\u6cd5\u548c\u94fe\u7684\u5199\u6cd5\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# ===== \u666e\u901a\u5199\u6cd5 =====\nmessages = prompt.invoke({\"question\": \"\u4f60\u597d\"})\nresponse = llm.invoke(messages)\nresult = parser.invoke(response)\n\n# ===== \u94fe\u7684\u5199\u6cd5\uff08\u7b49\u4ef7\uff09 =====\nchain = prompt | llm | parser\nresult = chain.invoke({\"question\": \"\u4f60\u597d\"})\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e24\u79cd\u5199\u6cd5\u7684\u7ed3\u679c\u5b8c\u5168\u4e00\u6837\uff0c\u4f46\u94fe\u7684\u5199\u6cd5\u66f4\u7b80\u6d01\uff0c\u800c\u4e14\u652f\u6301&nbsp;<code>.stream()<\/code>&nbsp;\u6d41\u5f0f\u8c03\u7528\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>\u8fd9\u5957\u7528&nbsp;<code>|<\/code>&nbsp;\u628a\u5404\u4e2a\u7ec4\u4ef6\u4e32\u6210\u94fe\u7684\u5199\u6cd5\uff0c\u6709\u4e2a\u6b63\u5f0f\u540d\u5b57\u53eb LCEL\uff08LangChain Expression Language\uff0cLangChain \u8868\u8fbe\u5f0f\u8bed\u8a00\uff09\u3002<\/strong>&nbsp;\u5b83\u662f LangChain \u63a8\u8350\u7684\u3001\u6784\u5efa\u94fe\u7684\u6807\u51c6\u65b9\u5f0f\u3002\u672c\u8bfe\u4ef6\u540e\u9762\uff08\u5305\u62ec\u591a\u8f6e\u5bf9\u8bdd\u3001RAG\uff09\u90fd\u4f1a\u7528 LCEL \u6765\u7ec4\u88c5\u94fe\u3002\u4e0b\u9762\u5148\u628a LCEL \u91cc\u6700\u5e38\u7528\u7684\u51e0\u4e2a\u4e1c\u897f\u8bb2\u6e05\u695a\uff1a\u94fe\u7684\u6784\u9020\u89c4\u5219\u3001<code>RunnableLambda<\/code>\u3001<code>RunnablePassthrough<\/code>\u3002<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\">\u94fe\u7684\u6784\u9020\u89c4\u5219<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5e76\u4e0d\u662f\u4efb\u610f\u5bf9\u8c61\u90fd\u80fd\u53c2\u4e0e\u94fe\u7684\u6784\u9020\uff0c\u6709\u4ee5\u4e0b\u89c4\u5219\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u89c4\u52191\uff1a\u53ea\u6709 Runnable \u5bf9\u8c61\u624d\u80fd\u53c2\u4e0e\u94fe\u7684\u6784\u9020<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">LangChain\u4e2d\u6240\u6709\u80fd\u53c2\u4e0e\u94fe\u7684\u7ec4\u4ef6\u90fd\u5b9e\u73b0\u4e86&nbsp;<code>Runnable<\/code>&nbsp;\u63a5\u53e3\uff08\u7c7b\u6bd4Java\u4e2d\u7684\u63a5\u53e3\u7ea6\u675f\uff09\u3002\u5e38\u89c1\u7684Runnable\u7ec4\u4ef6\u6709\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">\u7ec4\u4ef6<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u4f5c\u7528<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\"><code>ChatPromptTemplate<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u683c\u5f0f\u5316\u63d0\u793a\u8bcd<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><code>ChatOpenAI<\/code>&nbsp;(LLM)<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u8c03\u7528\u5927\u6a21\u578b<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><code>StrOutputParser<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u89e3\u6790\u8f93\u51fa\u4e3a\u5b57\u7b26\u4e32<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><code>RunnableWithMessageHistory<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u81ea\u52a8\u7ba1\u7406\u5386\u53f2\u6d88\u606f<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u666e\u901a\u7684Python\u51fd\u6570\u3001\u5b57\u7b26\u4e32\u3001\u5b57\u5178\u7b49<strong>\u4e0d\u80fd<\/strong>\u76f4\u63a5\u53c2\u4e0e\u94fe\u7684\u6784\u9020\uff08\u9664\u975e\u7528&nbsp;<code>RunnableLambda<\/code>&nbsp;\u5305\u88c5\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u89c4\u52192\uff1a\u524d\u4e00\u4e2a\u7ec4\u4ef6\u7684\u8f93\u51fa\u7c7b\u578b\u5fc5\u987b\u5339\u914d\u540e\u4e00\u4e2a\u7ec4\u4ef6\u7684\u8f93\u5165\u7c7b\u578b<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nChatPromptTemplate  \u2192  \u8f93\u51fa\uff1a\u6d88\u606f\u5217\u8868\nChatOpenAI          \u2192  \u8f93\u5165\uff1a\u6d88\u606f\u5217\u8868\uff0c\u8f93\u51fa\uff1aAIMessage\nStrOutputParser     \u2192  \u8f93\u5165\uff1aAIMessage\uff0c\u8f93\u51fa\uff1a\u5b57\u7b26\u4e32\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6240\u4ee5\u6b63\u786e\u7684\u987a\u5e8f\u662f\uff1a<code>prompt | llm | output_parser<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u5199\u6210&nbsp;<code>llm | prompt<\/code>&nbsp;\u5c31\u4f1a\u62a5\u9519\uff0c\u56e0\u4e3aLLM\u8f93\u51fa\u7684\u662fAIMessage\uff0c\u800cprompt\u671f\u671b\u7684\u8f93\u5165\u662f\u5b57\u5178\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u89c4\u52193\uff1a\u987a\u5e8f\u51b3\u5b9a\u4e86\u6570\u636e\u7684\u6d41\u5411<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u94fe\u7684\u6267\u884c\u987a\u5e8f\u4e25\u683c\u4ece\u5de6\u5230\u53f3\uff0c\u6570\u636e\u50cf\u6c34\u6d41\u4e00\u6837\u4f9d\u6b21\u7ecf\u8fc7\u6bcf\u4e2a\u7ec4\u4ef6\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u6b63\u786e\uff1a\u5148\u683c\u5f0f\u5316\u63d0\u793a\u8bcd \u2192 \u518d\u8c03\u7528\u6a21\u578b \u2192 \u6700\u540e\u89e3\u6790\u8f93\u51fa\nchain = prompt | llm | output_parser\n\n# \u9519\u8bef\uff1a\u987a\u5e8f\u53cd\u4e86\uff0c\u7c7b\u578b\u4e0d\u5339\u914d\nchain = output_parser | prompt | llm  # \u274c \u4f1a\u62a5\u9519\n```<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">RunnableLambda<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u524d\u9762\u8bf4\u8fc7\u666e\u901a\u7684Python\u51fd\u6570\u4e0d\u80fd\u76f4\u63a5\u53c2\u4e0e\u94fe\u7684\u6784\u9020\uff0c\u90a3\u5982\u679c\u6211\u5c31\u662f\u60f3\u5728\u94fe\u4e2d\u63d2\u5165\u4e00\u6bb5\u81ea\u5b9a\u4e49\u7684\u5904\u7406\u903b\u8f91\u600e\u4e48\u529e\uff1f\u7528&nbsp;<code>RunnableLambda<\/code>&nbsp;\u628a\u51fd\u6570\u5305\u88c5\u4e00\u4e0b\u5c31\u884c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u573a\u666f\uff1a\u7528\u6237\u7684\u539f\u59cb\u95ee\u9898\u4e0d\u80fd\u76f4\u63a5\u7ed9prompt\uff0c\u9700\u8981\u5148\u505a\u9884\u5904\u7406<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6bd4\u5982\u6211\u4eec\u60f3\u5728\u7528\u6237\u95ee\u9898\u524d\u9762\u7edf\u4e00\u52a0\u4e0a&#8221;\u7528\u6237\u54a8\u8be2\uff1a&#8221;\u7684\u524d\u7f00\uff0c\u8ba9\u6a21\u578b\u8bc6\u522b\u5f97\u66f4\u6e05\u695a\u3002\u5982\u679c\u4e0d\u7528\u94fe\uff0c\u53ef\u80fd\u8981\u8fd9\u6837\u5199\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u6ca1\u6709\u94fe\u7684\u5199\u6cd5\nquestion = \"\u4f60\u4eec\u7684\u9000\u8d27\u653f\u7b56\u662f\u4ec0\u4e48\uff1f\"\nprocessed = f\"\u7528\u6237\u54a8\u8be2\uff1a{question}\"                 # \u7b2c\u4e00\u6b65\uff1a\u624b\u52a8\u52a0\u524d\u7f00\nmessages = prompt.invoke({\"question\": processed})  # \u7b2c\u4e8c\u6b65\uff1a\u624b\u52a8\u683c\u5f0f\u5316\nresponse = llm.invoke(messages)                     # \u7b2c\u4e09\u6b65\uff1a\u624b\u52a8\u8c03\u6a21\u578b\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7528&nbsp;<code>RunnableLambda<\/code>&nbsp;\u628a&#8221;\u52a0\u524d\u7f00&#8221;\u8fd9\u4e2a\u666e\u901a\u51fd\u6570\u5305\u6210 Runnable\uff0c\u5c31\u53ef\u4ee5\u4e32\u5230\u94fe\u91cc\u4e86\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_core.runnables import RunnableLambda\n\n# 1. \u5b9a\u4e49\u4e00\u4e2a\u666e\u901a\u7684Python\u51fd\u6570\ndef add_prefix(inputs: dict) -&gt; dict:\n    \"\"\"\u7ed9\u95ee\u9898\u52a0\u4e0a\"\u7528\u6237\u54a8\u8be2\uff1a\"\u524d\u7f00\"\"\"\n    question = inputs[\"question\"]\n    return {\"question\": f\"\u7528\u6237\u54a8\u8be2\uff1a{question}\"}\n\n# 2. \u7528 RunnableLambda \u628a\u666e\u901a\u51fd\u6570\u5305\u88c5\u6210 Runnable\npreprocess = RunnableLambda(add_prefix)\n\n# 3. \u4e32\u5230\u94fe\u4e2d\uff1a\u9884\u5904\u7406 \u2192 \u683c\u5f0f\u5316\u63d0\u793a\u8bcd \u2192 \u8c03\u7528\u6a21\u578b\nchain = preprocess | prompt | llm\n\n# 4. \u8c03\u7528\u94fe\uff0c\u9884\u5904\u7406\u4f1a\u81ea\u52a8\u5728\u683c\u5f0f\u5316\u63d0\u793a\u8bcd\u4e4b\u524d\u6267\u884c\nresult = chain.invoke({\"question\": \"\u4f60\u4eec\u7684\u9000\u8d27\u653f\u7b56\u662f\u4ec0\u4e48\uff1f\"})\n# \u6a21\u578b\u5b9e\u9645\u770b\u5230\u7684\u95ee\u9898\u662f\uff1a\"\u7528\u6237\u54a8\u8be2\uff1a\u4f60\u4eec\u7684\u9000\u8d27\u653f\u7b56\u662f\u4ec0\u4e48\uff1f\"\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>RunnableLambda<\/code>&nbsp;\u5c31\u662f\u4e00\u4e2a\u9002\u914d\u5668\uff0c\u628a\u4efb\u4f55\u666e\u901a\u51fd\u6570\u90fd\u80fd\u8f6c\u6210\u53ef\u4ee5\u53c2\u4e0e\u94fe\u7684 Runnable\u3002\u5e38\u89c1\u7528\u9014\uff1a\u6570\u636e\u6e05\u6d17\u3001\u5b57\u6bb5\u63d0\u53d6\u3001\u683c\u5f0f\u8f6c\u6362\u7b49\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">RunnablePassthrough<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u94fe\u7684\u8f93\u5165\u662f\u4e00\u4e2a<strong>\u5b57\u5178<\/strong>\u65f6\uff0c\u7ecf\u5e38\u4f1a\u9047\u5230\u8fd9\u6837\u7684\u9700\u6c42\uff1a\u5728\u4e0d\u7834\u574f\u539f\u5b57\u5178\u7684\u524d\u63d0\u4e0b\uff0c\u7ed9\u5b83<strong>\u8865\u5145\u4e00\u4e2a\u65b0\u5b57\u6bb5<\/strong>\u3002<code>RunnablePassthrough<\/code>&nbsp;\u5c31\u662f\u5e72\u8fd9\u4e2a\u7684\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5148\u770b\u5b83\u6700\u57fa\u7840\u7684\u7528\u6cd5\u2014\u2014<code>RunnablePassthrough()<\/code>&nbsp;\u8868\u793a&#8221;\u539f\u6837\u4f20\u9012&#8221;\uff0c\u8f93\u5165\u4ec0\u4e48\u5c31\u8f93\u51fa\u4ec0\u4e48\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_core.runnables import RunnablePassthrough\n\nchain = RunnablePassthrough()\nprint(chain.invoke({\"question\": \"\u4f60\u597d\"}))   # \u539f\u6837\u8f93\u51fa {\"question\": \"\u4f60\u597d\"}\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5149&#8221;\u539f\u6837\u4f20\u9012&#8221;\u6ca1\u4ec0\u4e48\u7528\uff0c\u5b83\u7684\u5a01\u529b\u5728\u4e8e&nbsp;<code>.assign()<\/code>&nbsp;\u65b9\u6cd5\u2014\u2014<strong>\u5728\u539f\u8f93\u5165\u5b57\u5178\u7684\u57fa\u7840\u4e0a\uff0c\u65b0\u589e\u4e00\u4e2a\u952e\u503c\u5bf9<\/strong>\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u52a0\u5230\u54ea\u4e2a\u5b57\u5178<\/strong>\uff1a\u52a0\u5230\u5f53\u524d\u6d41\u7ecf\u8fd9\u6761\u94fe\u7684\u8f93\u5165\u5b57\u5178\u4e0a\uff08\u4e5f\u5c31\u662f\u00a0<code>invoke<\/code>\u00a0\u65f6\u4f20\u8fdb\u6765\u7684\u90a3\u4e2a\uff09\u3002<\/li>\n\n\n\n<li><strong>key\uff08\u952e\uff09\u600e\u4e48\u5b9a<\/strong>\uff1a\u5c31\u662f\u4f60\u5199\u5728\u00a0<code>assign(...)<\/code>\u00a0\u91cc\u7684\u90a3\u4e2a<strong>\u53c2\u6570\u540d<\/strong>\u3002\u6bd4\u5982\u00a0<code>assign(total=...)<\/code>\uff0c\u65b0\u589e\u7684 key \u5c31\u662f\u00a0<code>\"total\"<\/code>\u3002<\/li>\n\n\n\n<li><strong>value\uff08\u503c\uff09\u4ece\u54ea\u6765<\/strong>\uff1a\u628a<strong>\u539f\u8f93\u5165\u5b57\u5178<\/strong>\u6574\u4e2a\u4ea4\u7ed9\u7b49\u53f7\u53f3\u8fb9\u7684 Runnable \u53bb\u8fd0\u884c\uff0c\u5b83\u8fd4\u56de\u4ec0\u4e48\uff0c\u8fd9\u4e2a\u65b0 key \u7684 value \u5c31\u662f\u4ec0\u4e48\u3002<\/li>\n\n\n\n<li>\u539f\u5b57\u5178\u91cc\u5df2\u6709\u7684\u5b57\u6bb5<strong>\u539f\u6837\u4fdd\u7559<\/strong>\uff0c\u4e0d\u53d7\u5f71\u54cd\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3e\u4e2a\u6700\u5c0f\u7684\u4f8b\u5b50\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_core.runnables import RunnablePassthrough\n\n# \u7b49\u53f7\u53f3\u8fb9\u662f\u4e00\u4e2a Runnable\uff0c\u8fd9\u91cc\u7528 lambda \u5305\u4e00\u4e2a\u7b80\u5355\u51fd\u6570\n# \u5b83\u63a5\u6536\u6574\u4e2a\u8f93\u5165\u5b57\u5178 x\uff0c\u8fd4\u56de x[\"a\"] + x[\"b\"]\nchain = RunnablePassthrough.assign(total=lambda x: x[\"a\"] + x[\"b\"])\n\nprint(chain.invoke({\"a\": 3, \"b\": 5}))\n# \u8f93\u51fa\uff1a{\"a\": 3, \"b\": 5, \"total\": 8}\n#       \u2191 \u539f\u6709\u7684 a\u3001b \u539f\u6837\u4fdd\u7559    \u2191 \u65b0\u589e\u7684 key=\"total\"\uff0cvalue=\u53f3\u8fb9\u51fd\u6570\u7684\u8fd4\u56de\u503c\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>RunnablePassthrough.assign<\/code>&nbsp;\u5728\u540e\u9762\u7684 RAG \u91cc\u4f1a\u6d3e\u4e0a\u5927\u7528\u573a\u2014\u2014\u7528\u5b83\u6765\u7ed9\u8f93\u5165&#8221;\u81ea\u52a8\u8865\u4e0a\u68c0\u7d22\u5230\u7684\u5185\u5bb9&#8221;\u8fd9\u4e2a\u5b57\u6bb5\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u94fe\u7684\u8c03\u7528\u65b9\u5f0f<\/h3>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nchain = prompt | llm\n\n# \u65b9\u5f0f1\uff1ainvoke \u2014\u2014 \u540c\u6b65\u8c03\u7528\uff0c\u7b49\u5f85\u5b8c\u6574\u7ed3\u679c\nresult = chain.invoke({\"question\": \"\u4f60\u597d\"})\n\n# \u65b9\u5f0f2\uff1astream \u2014\u2014 \u6d41\u5f0f\u8c03\u7528\uff0c\u9010\u6b65\u83b7\u53d6\u7ed3\u679c\uff08\u7528\u4e8eSSE\uff09\nfor chunk in chain.stream({\"question\": \"\u4f60\u597d\"}):\n    print(chunk)\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">&#8212;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u56db\u3001\u591a\u8f6e\u5bf9\u8bdd\uff08\u4f1a\u8bdd\u8bb0\u5fc6\uff09<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u524d\u9762\u7684\u5bf9\u8bdd\u90fd\u662f&#8221;\u4e00\u9524\u5b50\u4e70\u5356&#8221;\u2014\u2014\u6a21\u578b\u56de\u7b54\u5b8c\u5c31\u5fd8\u4e86\uff0c\u4e0b\u4e00\u6b21\u63d0\u95ee\u5b83\u5b8c\u5168\u4e0d\u8bb0\u5f97\u4e0a\u4e00\u8f6e\u804a\u4e86\u4ec0\u4e48\u3002\u8981\u5b9e\u73b0<strong>\u591a\u8f6e\u5bf9\u8bdd<\/strong>\uff0c\u6838\u5fc3\u5c31\u662f<strong>\u4f1a\u8bdd\u8bb0\u5fc6<\/strong>\uff1a\u628a\u5386\u53f2\u5bf9\u8bdd\u4fdd\u5b58\u4e0b\u6765\uff0c\u6bcf\u6b21\u63d0\u95ee\u65f6\u8fde\u540c\u5386\u53f2\u4e00\u8d77\u53d1\u7ed9\u6a21\u578b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b9e\u73b0\u4f1a\u8bdd\u8bb0\u5fc6\u8981\u89e3\u51b3\u4e24\u4e2a\u95ee\u9898\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4f1a\u8bdd\u8bb0\u5fc6\u7684\u4fdd\u5b58\u548c\u9694\u79bb<\/strong>\uff1a\u5386\u53f2\u6d88\u606f\u5b58\u5728\u54ea\uff1f\u5982\u4f55\u533a\u5206\u4e0d\u540c\u7684\u4f1a\u8bdd\uff1f<\/li>\n\n\n\n<li><strong>\u4e0a\u4e0b\u6587\u7ec4\u7ec7<\/strong>\uff1a\u5728\u591a\u8f6e\u5bf9\u8bdd\u7684\u6bcf\u4e00\u8f6e\u5bf9\u8bdd\u4e2d\uff0c\u5230\u5e95\u7ed9\u6a21\u578b\u53d1\u9001\u54ea\u4e9b\u5185\u5bb9\uff1f<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">\u4f1a\u8bdd\u8bb0\u5fc6\u5b58\u7684\u4fdd\u5b58\u548c\u9694\u79bb<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">LangChain\u652f\u6301\u591a\u79cd\u4f1a\u8bdd\u8bb0\u5fc6\u7684\u6301\u4e45\u5316\u65b9\u5f0f\uff0c\u5e76\u63d0\u4f9b\u4e86\u5f00\u7bb1\u5373\u7528\u7684\u5b9e\u73b0\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">\u6301\u4e45\u5316\u65b9\u5f0f<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u5bf9\u5e94\u7c7b<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u7279\u70b9<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\">\u5185\u5b58<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>ChatMessageHistory<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u8fdb\u7a0b\u91cd\u542f\u540e\u4e22\u5931\uff0c\u4ec5\u9002\u5408\u6d4b\u8bd5<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">Redis<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>RedisChatMessageHistory<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u9ad8\u6027\u80fd\uff0c\u652f\u6301TTL\u81ea\u52a8\u8fc7\u671f\uff0c\u9002\u5408\u751f\u4ea7\u73af\u5883<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">PostgreSQL<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>PostgresChatMessageHistory<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6301\u4e45\u5316\u5230\u5173\u7cfb\u6570\u636e\u5e93<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">MongoDB<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>MongoDBChatMessageHistory<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6301\u4e45\u5316\u5230\u6587\u6863\u6570\u636e\u5e93<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u6587\u4ef6\u7cfb\u7edf<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>FileChatMessageHistory<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6301\u4e45\u5316\u5230\u672c\u5730\u6587\u4ef6<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u6211\u4eec\u7684\u9879\u76ee\u4e2d\u4f7f\u7528 Redis\uff08<code>RedisChatMessageHistory<\/code>\uff09<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b58\u50a8\u5728RedisChatMessageHistory\u4e2d\u7684\u4f1a\u8bdd\u8bb0\u5fc6\u600e\u4e48\u9694\u79bb\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>RedisChatMessageHistory<\/code>&nbsp;\u901a\u8fc7\u4e00\u4e2a&nbsp;<code>session_id<\/code>&nbsp;\u53c2\u6570\u6765\u9694\u79bb\u4e0d\u540c\u7528\u6237\u7684\u4f1a\u8bdd\u2014\u2014\u7ed9\u6bcf\u4e2a\u4f1a\u8bdd\u5206\u914d\u4e00\u4e2a\u552f\u4e00\u7684&nbsp;<code>session_id<\/code>\uff0c\u4fdd\u5b58\u548c\u8bfb\u53d6\u65f6\u90fd\u5e26\u4e0a\u5b83\uff0c\u4e0d\u540c\u4f1a\u8bdd\u7684\u6d88\u606f\u5c31\u5206\u5f00\u5b58\u4e86\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_community.chat_message_histories import RedisChatMessageHistory\n\ndef get_history(session_id: str) -&gt; RedisChatMessageHistory:\n    return RedisChatMessageHistory(\n        session_id=session_id,          # \u7528 session_id \u9694\u79bb\u4e0d\u540c\u4f1a\u8bdd\n        url=\"redis:\/\/localhost:6379\", # Redis\u8fde\u63a5\u5730\u5740\n        key_prefix=\"chat:\",             # key\u524d\u7f00\uff0c\u6700\u7ec8key\u4e3a chat:{session_id}\n        ttl=604800,                     # 7\u5929\u81ea\u52a8\u8fc7\u671f\n    )\n```<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u4f1a\u8bdd\u8bb0\u5fc6\u7684\u81ea\u52a8\u7ba1\u7406<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6709\u4e86&nbsp;<code>RedisChatMessageHistory<\/code>\uff0c\u662f\u4e0d\u662f\u6bcf\u8f6e\u5bf9\u8bdd\u90fd\u8981\u6211\u4eec\u81ea\u5df1\u8c03\u5b83\u7684&nbsp;<code>add_messages()<\/code>&nbsp;\u6765\u4fdd\u5b58\u7528\u6237\u8f93\u5165\u548c\u6a21\u578b\u56de\u7b54\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u9700\u8981\u3002LangChain \u63d0\u4f9b\u4e86\u4e00\u4e2a\u53eb&nbsp;<code>RunnableWithMessageHistory<\/code>&nbsp;\u7684\u5c01\u88c5\uff0c\u4e13\u95e8\u5e2e\u6211\u4eec\u81ea\u52a8\u5b8c\u6210&#8221;\u8bfb\u5386\u53f2\u3001\u62fc\u5386\u53f2\u3001\u5199\u5386\u53f2&#8221;\u8fd9\u4e9b\u4e8b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>RunnableWithMessageHistory<\/code>&nbsp;\u662f\u4e00\u4e2a<strong>\u94fe\u7684\u5305\u88c5\u5668<\/strong>\uff0c\u5b83\u5305\u88c5\u4e00\u4e2a\u57fa\u7840\u94fe\uff0c\u81ea\u52a8\u4e3a\u8fd9\u4e2a\u94fe\u7ef4\u62a4\u4f1a\u8bdd\u8bb0\u5fc6\u3002\u5b83\u7684\u6838\u5fc3\u804c\u8d23\u5c31\u4e09\u4ef6\u4e8b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u8c03\u7528\u524d<\/strong>\uff1a\u6839\u636e\u00a0<code>session_id<\/code>\u00a0\u8c03\u7528\u00a0<code>get_session_history<\/code>\u00a0\u62ff\u5230\u8fd9\u4e2a\u4f1a\u8bdd\u7684\u5386\u53f2\u5bf9\u8c61\uff0c\u8bfb\u51fa\u5386\u53f2\u6d88\u606f<\/li>\n\n\n\n<li><strong>\u8c03\u7528\u4e2d<\/strong>\uff1a\u628a\u5386\u53f2\u6d88\u606f\u4ea4\u7ed9\u57fa\u7840\u94fe\uff0c\u8ba9\u5386\u53f2\u53c2\u4e0e\u5230\u672c\u6b21\u6a21\u578b\u8c03\u7528\u4e2d<\/li>\n\n\n\n<li><strong>\u8c03\u7528\u540e<\/strong>\uff1a\u628a\u672c\u8f6e\u7684&#8221;\u7528\u6237\u6d88\u606f&#8221;\u548c&#8221;\u6a21\u578b\u56de\u7b54&#8221;\u8ffd\u52a0\u5199\u56de\u5386\u53f2<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f46<strong>\u7b2c2\u6b65&#8221;\u5386\u53f2\u6d88\u606f\u600e\u4e48\u4ea4\u7ed9\u57fa\u7840\u94fe&#8221;\uff0c\u5206\u4e24\u79cd\u60c5\u51b5<\/strong>\uff0c\u53d6\u51b3\u4e8e\u4f60\u7684\u57fa\u7840\u94fe\u63a5\u6536\u7684\u8f93\u5165\u662f\u4ec0\u4e48\u2014\u2014\u662f<strong>\u5355\u6761\u6d88\u606f<\/strong>\uff0c\u8fd8\u662f<strong>\u5b57\u5178\uff08dict\uff09<\/strong>\u3002\u8fd9\u4e24\u79cd\u60c5\u51b5\u7684\u5199\u6cd5\u5dee\u522b\u5f88\u5927\uff0c\u4e0b\u9762\u5206\u522b\u8bb2\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u60c5\u51b5\u4e00\uff1a\u8f93\u5165\u662f\u5355\u6761\u6d88\u606f\uff08\u6700\u7b80\u5355\uff09<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u57fa\u7840\u94fe\u76f4\u63a5\u5c31\u662f\u4e00\u4e2a&nbsp;<code>llm<\/code>\uff08\u6216&nbsp;<code>llm | parser<\/code>\uff09\uff0c\u8f93\u5165\u662f\u7528\u6237\u7684\u4e00\u6761\u6d88\u606f\uff0c\u90a3&nbsp;<code>RunnableWithMessageHistory<\/code>&nbsp;\u4f1a\u628a&#8221;\u5386\u53f2\u6d88\u606f + \u5f53\u524d\u6d88\u606f&#8221;\u62fc\u6210\u4e00\u4e2a\u6d88\u606f\u5217\u8868\u76f4\u63a5\u5582\u7ed9\u6a21\u578b\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b<strong>\u4e0d\u9700\u8981\u63d0\u793a\u8bcd\u6a21\u677f\uff0c\u4e5f\u4e0d\u9700\u8981\u6307\u5b9a\u4efb\u4f55 key<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import ChatOpenAI\nfrom langchain_core.runnables.history import RunnableWithMessageHistory\nfrom langchain_community.chat_message_histories import RedisChatMessageHistory\n\nllm = ChatOpenAI(model=\"qwen-plus\", api_key=\"...\", base_url=\"...\")\n\n# \u57fa\u7840\u94fe\u5c31\u662f llm \u672c\u8eab\uff0c\u8f93\u5165\/\u8f93\u51fa\u90fd\u662f\u6d88\u606f\nchain_with_history = RunnableWithMessageHistory(\n    llm,                          # \u57fa\u7840\u94fe\uff1a\u76f4\u63a5\u662f llm\n    get_session_history=get_history\n)\n\n# \u8c03\u7528\u65f6\u76f4\u63a5\u4f20\u4e00\u6761\u6d88\u606f\uff08\u5b57\u7b26\u4e32\u4f1a\u88ab\u5f53\u6210 HumanMessage\uff09\nresult = chain_with_history.invoke(\n    \"\u6211\u53eb\u5f20\u4e09\",\n    config={\"configurable\": {\"session_id\": \"abc-123\"}},\n)\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u79cd\u6a21\u5f0f\u4e0b\uff0c<code>RunnableWithMessageHistory<\/code>&nbsp;\u81ea\u52a8\u628a\u5386\u53f2\u6d88\u606f\u5217\u8868\u548c\u5f53\u524d\u6d88\u606f<strong>\u62fc\u5728\u4e00\u8d77<\/strong>\u4f5c\u4e3a\u6a21\u578b\u8f93\u5165\uff0c\u4f60\u4ec0\u4e48\u90fd\u4e0d\u7528\u7ba1\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f46\u5b83\u7684\u5c40\u9650\u4e5f\u5f88\u660e\u663e\uff1a<strong>\u6ca1\u6cd5\u52a0\u7cfb\u7edf\u63d0\u793a\u8bcd\u3001\u6ca1\u6cd5\u5728\u5386\u53f2\u524d\u540e\u63d2\u5165\u522b\u7684\u5185\u5bb9<\/strong>\u2014\u2014\u56e0\u4e3a\u8f93\u5165\u5c31\u662f\u4e00\u4e32\u7eaf\u6d88\u606f\u3002\u5b9e\u9645\u9879\u76ee\u91cc\u6211\u4eec\u51e0\u4e4e\u603b\u8981\u52a0\u7cfb\u7edf\u63d0\u793a\u8bcd\uff08\u6307\u5b9a\u89d2\u8272\u3001\u6ce8\u5165\u77e5\u8bc6\u7b49\uff09\uff0c\u6240\u4ee5\u66f4\u5e38\u7528\u7684\u662f\u4e0b\u9762\u7b2c\u4e8c\u79cd\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u60c5\u51b5\u4e8c\uff1a\u8f93\u5165\u662f\u5b57\u5178\uff08\u9700\u8981\u63d0\u793a\u8bcd\u6a21\u677f\uff09<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u57fa\u7840\u94fe\u662f&nbsp;<code>prompt | llm<\/code>&nbsp;\u8fd9\u79cd\u5e26\u63d0\u793a\u8bcd\u6a21\u677f\u7684\u94fe\u65f6\uff0c\u94fe\u7684\u8f93\u5165\u662f\u4e00\u4e2a<strong>\u5b57\u5178<\/strong>\uff08\u6bd4\u5982&nbsp;<code>{\"question\": \"...\"}<\/code>\uff09\uff0c\u7531\u6a21\u677f\u53bb\u586b\u5145\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b\u6709\u4e24\u4e2a\u5173\u952e\u7ea6\u5b9a\uff0c\u5fc5\u987b\u81ea\u5df1\u5904\u7406\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u57fa\u7840\u94fe\u5fc5\u987b\u6709\u00a0<code>ChatPromptTemplate<\/code>\u00a0\u6a21\u677f<\/strong>\uff0c\u800c\u4e14\u6a21\u677f\u91cc\u8981\u7528\u00a0<code>MessagesPlaceholder<\/code>\u00a0\u663e\u5f0f\u5360\u4e00\u4e2a&#8221;\u5386\u53f2\u6d88\u606f&#8221;\u7684\u4f4d\u7f6e\u2014\u2014<strong>\u6846\u67b6\u4e0d\u4f1a\u81ea\u52a8\u5e2e\u4f60\u628a\u5386\u53f2\u62fc\u8fdb\u53bb<\/strong>\uff0c\u5b83\u53ea\u8d1f\u8d23\u628a\u5386\u53f2<strong>\u653e\u5230\u4f60\u6307\u5b9a\u7684\u90a3\u4e2a\u5360\u4f4d\u7b26<\/strong>\uff0c\u5230\u5e95\u63d2\u5728\u7cfb\u7edf\u63d0\u793a\u8bcd\u540e\u9762\u8fd8\u662f\u54ea\u91cc\uff0c\u7531\u4f60\u5728\u6a21\u677f\u91cc\u51b3\u5b9a\u3002<\/li>\n\n\n\n<li><strong>\u5fc5\u987b\u544a\u8bc9\u6846\u67b6\u4e24\u4e2a key<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>input_messages_key<\/code>\uff1a\u8f93\u5165\u5b57\u5178\u91cc\u54ea\u4e2a key \u662f&#8221;\u5f53\u524d\u7528\u6237\u6d88\u606f&#8221;\uff08\u6846\u67b6\u8981\u628a\u5b83\u5199\u56de\u5386\u53f2\uff09<\/li>\n\n\n\n<li><code>history_messages_key<\/code>\uff1a\u628a\u8bfb\u51fa\u6765\u7684\u5386\u53f2\u585e\u5230\u6a21\u677f\u7684\u54ea\u4e2a\u00a0<code>MessagesPlaceholder<\/code>\uff08\u540d\u5b57\u8981\u5bf9\u5f97\u4e0a\uff09<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import ChatOpenAI\nfrom langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder\nfrom langchain_core.runnables.history import RunnableWithMessageHistory\nfrom langchain_community.chat_message_histories import RedisChatMessageHistory\n\nllm = ChatOpenAI(model=\"qwen-plus\", api_key=\"...\", base_url=\"...\")\n\n# 1. \u63d0\u793a\u8bcd\u6a21\u677f\uff1a\u5fc5\u987b\u81ea\u5df1\u7528 MessagesPlaceholder \u5360\u597d\u5386\u53f2\u6d88\u606f\u7684\u4f4d\u7f6e\nprompt = ChatPromptTemplate.from_messages([\n    (\"system\", \"\u4f60\u662f\u4e00\u4f4d\u53cb\u597d\u7684\u52a9\u624b\"),\n    MessagesPlaceholder(\"history\"),   # \u2190 \u5386\u53f2\u6d88\u606f\u4f1a\u88ab\u585e\u5230\u8fd9\u91cc\uff08\u4f4d\u7f6e\u7531\u4f60\u51b3\u5b9a\uff09\n    (\"human\", \"{question}\"),           # \u5f53\u524d\u7528\u6237\u6d88\u606f\n])\n\n# 2. \u57fa\u7840\u94fe\uff1a\u5e26\u6a21\u677f\nbase_chain = prompt | llm\n\n# 3. \u5305\u88c5\u65f6\uff0c\u5fc5\u987b\u6307\u5b9a\u4e24\u4e2a key\nchain_with_history = RunnableWithMessageHistory(\n    base_chain,\n    get_session_history=lambda session_id: RedisChatMessageHistory(\n        session_id=session_id,\n        url=\"redis:\/\/localhost:6379\",\n        key_prefix=\"chat:\"\n    ),\n    input_messages_key=\"question\",     # \u8f93\u5165\u5b57\u5178\u91cc\"\u7528\u6237\u95ee\u9898\"\u5bf9\u5e94\u7684 key\n    history_messages_key=\"history\",     # \u5386\u53f2\u585e\u5230\u6a21\u677f\u91cc\u540d\u4e3a history \u7684\u5360\u4f4d\u7b26\n)\n\n# 4. \u8c03\u7528\u65f6\u4f20\u5b57\u5178\uff08key \u8981\u548c\u6a21\u677f\u5bf9\u5f97\u4e0a\uff09\uff0c\u5e76\u901a\u8fc7 config \u4f20\u5165 session_id\nresult = chain_with_history.invoke(\n    {\"question\": \"\u6211\u53eb\u5f20\u4e09\"},\n    config={\"configurable\": {\"session_id\": \"abc-123\"}},\n)\n# \u4e0b\u4e00\u6b21\u7528\u540c\u4e00\u4e2a session_id \u63d0\u95ee\uff0c\u6a21\u578b\u5c31\u80fd\u8bb0\u5f97\"\u4f60\u53eb\u5f20\u4e09\"\nresult = chain_with_history.invoke(\n    {\"question\": \"\u6211\u53eb\u4ec0\u4e48\u540d\u5b57\uff1f\"},\n    config={\"configurable\": {\"session_id\": \"abc-123\"}},\n)\n# \u6a21\u578b\u56de\u7b54\uff1a\"\u4f60\u53eb\u5f20\u4e09\"\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4e24\u79cd\u60c5\u51b5\u5bf9\u6bd4\uff1a<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\"><\/th><th class=\"has-text-align-left\" data-align=\"left\">\u60c5\u51b5\u4e00\uff1a\u8f93\u5165\u662f\u6d88\u606f<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u60c5\u51b5\u4e8c\uff1a\u8f93\u5165\u662f\u5b57\u5178<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\">\u57fa\u7840\u94fe<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u76f4\u63a5&nbsp;<code>llm<\/code><\/td><td class=\"has-text-align-left\" data-align=\"left\">`prompt<\/td><td class=\"has-text-align-left\" data-align=\"left\">llm`\uff08\u5fc5\u987b\u6709\u6a21\u677f\uff09<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u63d0\u793a\u8bcd\u6a21\u677f<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u4e0d\u9700\u8981<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u5fc5\u987b\uff0c\u4e14\u8981\u6709&nbsp;<code>MessagesPlaceholder<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u5386\u53f2\u62fc\u63a5<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6846\u67b6\u81ea\u52a8\u62fc\u5230\u6d88\u606f\u5217\u8868<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6846\u67b6\u585e\u5230\u4f60\u6307\u5b9a\u7684\u5360\u4f4d\u7b26\uff0c<strong>\u62fc\u63a5\u4f4d\u7f6e\u7531\u4f60\u7684\u6a21\u677f\u51b3\u5b9a<\/strong><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u9700\u8981\u6307\u5b9a key<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u4e0d\u9700\u8981<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u5fc5\u987b\u6307\u5b9a&nbsp;<code>input_messages_key<\/code>&nbsp;\u548c&nbsp;<code>history_messages_key<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u80fd\u5426\u52a0\u7cfb\u7edf\u63d0\u793a\u8bcd<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u4e0d\u80fd<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u80fd\uff08\u5728\u6a21\u677f\u91cc\u5199\uff09<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b9e\u9645\u9879\u76ee\u91cc\u51e0\u4e4e\u90fd\u7528<strong>\u60c5\u51b5\u4e8c<\/strong>\u2014\u2014\u56e0\u4e3a\u6211\u4eec\u603b\u8981\u52a0\u7cfb\u7edf\u63d0\u793a\u8bcd\u3001\u6ce8\u5165\u77e5\u8bc6\u7b49\uff0c\u79bb\u4e0d\u5f00\u63d0\u793a\u8bcd\u6a21\u677f\u3002\u4e0b\u9762\u7684\u5185\u5bb9\u4e5f\u90fd\u4ee5\u60c5\u51b5\u4e8c\u4e3a\u57fa\u7840\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u4f1a\u8bdd\u8bb0\u5fc6\u7684\u88c1\u526a<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>RunnableWithMessageHistory<\/code>&nbsp;\u9ed8\u8ba4\u4f1a\u8bfb\u53d6\u8be5&nbsp;<code>session_id<\/code>&nbsp;\u4e0b\u7684<strong>\u5168\u90e8<\/strong>\u5386\u53f2\u6d88\u606f\u3002\u4f46\u628a\u6240\u6709\u5386\u53f2\u90fd\u62fc\u8fdb\u63d0\u793a\u8bcd\u662f\u4e0d\u884c\u7684\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u6a21\u578b\u6709\u4e0a\u4e0b\u6587\u7a97\u53e3\u9650\u5236\uff08token\u6570\u91cf\u6709\u4e0a\u9650\uff09<\/li>\n\n\n\n<li>\u6d88\u606f\u8d8a\u591a\uff0c\u8c03\u7528\u6210\u672c\u8d8a\u9ad8\uff08\u6309token\u8ba1\u8d39\uff09<\/li>\n\n\n\n<li>\u8fc7\u591a\u7684\u5386\u53f2\u6d88\u606f\u53ef\u80fd\u5f15\u5165\u566a\u97f3\uff0c\u53cd\u800c\u964d\u4f4e\u56de\u7b54\u8d28\u91cf<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u6240\u4ee5\u901a\u5e38\u91c7\u7528<strong>\u7a97\u53e3\u7b56\u7565<\/strong>\uff1a\u53ea\u4fdd\u7559\u6700\u8fd1 N \u6761\u6d88\u606f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6700\u7b80\u5355\u7684\u505a\u6cd5\u662f\u5199\u4e00\u4e2a\u666e\u901a\u51fd\u6570\u5bf9\u5386\u53f2\u5217\u8868\u505a\u5207\u7247\uff0c\u518d\u7528&nbsp;<code>RunnableLambda<\/code>&nbsp;\u628a\u5b83\u4e32\u8fdb\u94fe\u91cc\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_core.runnables import RunnableLambda\n\nWINDOW = 20  # \u4fdd\u7559\u6700\u8fd120\u6761\n\ndef trim_history(inputs: dict) -&gt; dict:\n    \"\"\"\u88c1\u526a\u8f93\u5165\u5b57\u5178\u4e2d\u7684\u5386\u53f2\u6d88\u606f\uff0c\u53ea\u4fdd\u7559\u6700\u8fd1 WINDOW \u6761\"\"\"\n    values = dict(inputs)\n    history = values.get(\"history\")\n    if isinstance(history, list):\n        values[\"history\"] = history[-WINDOW:]   # \u5217\u8868\u5207\u7247\uff0c\u4fdd\u7559\u6700\u540eN\u6761\n    return values\n\n# \u628a\u88c1\u526a\u51fd\u6570\u4e32\u5728 prompt \u4e4b\u524d\n# \u6570\u636e\u6d41\uff1a\u8bfb\u5386\u53f2(\u81ea\u52a8) \u2192 \u88c1\u526a(\u6211\u4eec\u5199\u7684\u51fd\u6570) \u2192 \u62fc\u63a5\u63d0\u793a\u8bcd \u2192 \u8c03\u7528\u6a21\u578b\nbase_chain = RunnableLambda(trim_history) | prompt | llm\n\nchain_with_history = RunnableWithMessageHistory(\n    base_chain,\n    get_session_history=get_history,\n    input_messages_key=\"question\",\n    history_messages_key=\"history\",\n)\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4e3a\u4ec0\u4e48&nbsp;<code>inputs<\/code>&nbsp;\u91cc\u4f1a\u6709&nbsp;<code>history<\/code>&nbsp;\u5b57\u6bb5\uff1f<\/strong>&nbsp;\u56e0\u4e3a&nbsp;<code>RunnableWithMessageHistory<\/code>&nbsp;\u5728\u94fe\u6267\u884c\u524d\u4f1a<strong>\u81ea\u52a8<\/strong>\u628a\u5386\u53f2\u6d88\u606f\u8bfb\u51fa\u6765\u585e\u8fdb&nbsp;<code>inputs<\/code>&nbsp;\u5b57\u5178\uff0ckey \u5c31\u662f\u914d\u7f6e\u7684&nbsp;<code>history_messages_key=\"history\"<\/code>\u3002\u6240\u4ee5\u7b49&nbsp;<code>trim_history<\/code>&nbsp;\u6267\u884c\u65f6\uff0c<code>inputs<\/code>&nbsp;\u91cc\u5df2\u7ecf\u6709&nbsp;<code>{\"question\": \"...\", \"history\": [\u5386\u53f2\u6d88\u606f\u5217\u8868]}<\/code>&nbsp;\u4e86\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5b8c\u6574\u6570\u636e\u6d41\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nchain_with_history.invoke({\"question\": \"...\"}, config={\"session_id\": \"abc\"})\n   \u2193\nRunnableWithMessageHistory \u8bfb\u53d6\u5b58\u50a8\u4e2d abc \u4f1a\u8bdd\u7684\u5168\u90e8\u5386\u53f2\n   \u2193 \u5728 inputs \u4e2d\u6dfb\u52a0 \"history\": [\u5168\u90e8\u5386\u53f2]\nRunnableLambda(trim_history) \u628a history \u5207\u7247\u4e3a\u6700\u8fd120\u6761\n   \u2193 inputs \u53d8\u4e3a {\"question\": \"...\", \"history\": [\u6700\u8fd120\u6761]}\nprompt \u628a20\u6761\u5386\u53f2 + \u5f53\u524d\u95ee\u9898 \u62fc\u6210\u5b8c\u6574\u6d88\u606f\u5217\u8868\n   \u2193\nllm \u8c03\u7528\u6a21\u578b\u751f\u6210\u56de\u7b54\n   \u2193\nRunnableWithMessageHistory \u628a\"\u5f53\u524d\u7528\u6237\u6d88\u606f\"\u548c\"\u6a21\u578b\u56de\u7b54\"\u8ffd\u52a0\u5199\u56de\u5b58\u50a8\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5173\u952e\u70b9\uff1a<\/strong>&nbsp;\u5b58\u50a8\u91cc\u59cb\u7ec8\u4fdd\u7559<strong>\u5b8c\u6574\u5386\u53f2<\/strong>\uff0c\u6bcf\u6b21\u8c03\u7528\u6a21\u578b\u65f6\u624d<strong>\u4e34\u65f6<\/strong>\u88c1\u526a\u523020\u6761\u3002\u8fd9\u6837\u5b58\u50a8\u7684\u6570\u636e\u59cb\u7ec8\u5b8c\u6574\uff0c\u800c\u6a21\u578b\u4e0d\u4f1a\u88ab\u8d85\u957f\u4e0a\u4e0b\u6587\u6df9\u6ca1\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">&#8212;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">RAG\uff08\u68c0\u7d22\u589e\u5f3a\u751f\u6210\uff09<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\u6211\u4eec\u7528\u4e00\u4efd\u300a\u5458\u5de5\u8bf7\u5047\u7ba1\u7406\u5236\u5ea6\u300b\u6587\u6863\uff0c\u4ece\u96f6\u5b9e\u73b0\u4e00\u4e2a\u6700\u57fa\u7840\u7684 RAG\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u9700\u8981\u989d\u5916\u5b89\u88c5\u7684\u4f9d\u8d56\uff1a<\/p>\n<\/blockquote>\n\n\n\n<pre class=\"wp-block-preformatted\">```\npip install langchain-text-splitters langchain-chroma chromadb\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4efd&nbsp;<code>\u5458\u5de5\u8bf7\u5047\u7ba1\u7406\u5236\u5ea6.md<\/code>\uff0c\u5185\u5bb9\u8282\u9009\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n## \u7b2c\u4e09\u7ae0 \u5e74\u5047\n\u7b2c\u4e94\u6761 \u5e74\u5047\u5929\u6570\u6839\u636e\u7d2f\u8ba1\u5de5\u4f5c\u5e74\u9650\u786e\u5b9a\uff1a\u7d2f\u8ba1\u5de5\u4f5c\u6ee11\u5e74\u4e0d\u6ee110\u5e74\u7684\uff0c\u5e74\u50475\u5929\uff1b\n\u6ee110\u5e74\u4e0d\u6ee120\u5e74\u7684\uff0c\u5e74\u504710\u5929\uff1b\u6ee120\u5e74\u4ee5\u4e0a\u7684\uff0c\u5e74\u504715\u5929\u3002\n\n## \u7b2c\u4e94\u7ae0 \u4e8b\u5047\n\u7b2c\u5341\u4e09\u6761 \u4e8b\u5047\u6bcf\u6708\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc73\u5929\uff0c\u5168\u5e74\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc715\u5929\u3002\u8d85\u8fc7\u9650\u989d\u7684\uff0c\u516c\u53f8\u6709\u6743\u4e0d\u4e88\u6279\u51c6\u3002\n\n## \u7b2c\u516b\u7ae0 \u8bf7\u5047\u5ba1\u6279\u6d41\u7a0b\n\u7b2c\u4e8c\u5341\u6761 \u5ba1\u6279\u6743\u9650\u5982\u4e0b\uff1a\u8bf7\u50471\u5929\u4ee5\u5185\uff08\u542b1\u5929\uff09\u7531\u76f4\u5c5e\u4e3b\u7ba1\u5ba1\u6279\uff1b\u8bf7\u50472\u5929\u81f33\u5929\u7531\u90e8\u95e8\u8d1f\u8d23\u4eba\u5ba1\u6279\uff1b\n\u8bf7\u50473\u5929\u4ee5\u4e0a\u7531\u90e8\u95e8\u8d1f\u8d23\u4eba\u548c\u4eba\u529b\u8d44\u6e90\u90e8\u5171\u540c\u5ba1\u6279\uff1b\u8bf7\u50477\u5929\u4ee5\u4e0a\u9700\u62a5\u603b\u7ecf\u7406\u5ba1\u6279\u3002\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u7684\u76ee\u6807\uff1a\u8ba9\u6a21\u578b\u80fd\u51c6\u786e\u56de\u7b54&#8221;\u4e8b\u5047\u4e00\u5e74\u6700\u591a\u8bf7\u51e0\u5929&#8221;&#8221;\u8bf75\u5929\u5047\u8c01\u6765\u5ba1\u6279&#8221;\u8fd9\u7c7b\u95ee\u9898\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u52a0\u8f7d\u6587\u6863<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">RAG \u7684\u7b2c\u4e00\u6b65\u662f\u628a\u6587\u6863\u8bfb\u8fdb\u7a0b\u5e8f\u3002LangChain \u63d0\u4f9b\u4e86\u5404\u79cd&nbsp;<code>Loader<\/code>\uff08\u52a0\u8f7d\u5668\uff09\u6765\u8bfb\u53d6\u4e0d\u540c\u683c\u5f0f\u7684\u6587\u4ef6\uff08txt\u3001md\u3001pdf\u3001word\u2026\u2026\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u6211\u4eec\u7684\u6587\u6863\u662f Markdown \u6587\u672c\u6587\u4ef6\uff0c\u7528&nbsp;<code>TextLoader<\/code>&nbsp;\u5373\u53ef\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_community.document_loaders import TextLoader\n\n# \u521b\u5efa\u52a0\u8f7d\u5668\uff0c\u6307\u5b9a\u6587\u4ef6\u8def\u5f84\u548c\u7f16\u7801\nloader = TextLoader(\"\u5458\u5de5\u8bf7\u5047\u7ba1\u7406\u5236\u5ea6.md\", encoding=\"utf-8\")\n\n# load() \u8fd4\u56de\u4e00\u4e2a Document \u5217\u8868\ndocuments = loader.load()\n\n# \u6574\u4e2a\u6587\u4ef6\u4f1a\u88ab\u8bfb\u6210 1 \u4e2a Document\n# Document \u6709\u4e24\u4e2a\u6838\u5fc3\u5c5e\u6027\uff1a\n#   - page_content: \u6587\u6863\u7684\u6587\u672c\u5185\u5bb9\n#   - metadata:     \u5143\u6570\u636e\uff08\u5982\u6765\u6e90\u6587\u4ef6\u8def\u5f84\u7b49\uff09\nprint(documents[0].page_content[:50])   # \u6253\u5370\u524d50\u4e2a\u5b57\nprint(documents[0].metadata)            # {'source': '\u5458\u5de5\u8bf7\u5047\u7ba1\u7406\u5236\u5ea6.md'}\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5173\u952e\u6982\u5ff5&nbsp;<code>Document<\/code>\uff1a<\/strong>&nbsp;LangChain \u7528&nbsp;<code>Document<\/code>&nbsp;\u5bf9\u8c61\u7edf\u4e00\u8868\u793a\u4e00\u6bb5\u6587\u6863\uff0c\u5b83\u5305\u542b&nbsp;<code>page_content<\/code>\uff08\u6b63\u6587\uff09\u548c&nbsp;<code>metadata<\/code>\uff08\u5143\u6570\u636e\uff09\u3002\u540e\u9762\u5207\u5206\u3001\u5411\u91cf\u5316\u3001\u68c0\u7d22\uff0c\u64cd\u4f5c\u7684\u90fd\u662f&nbsp;<code>Document<\/code>\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u5207\u5206\u6587\u6863<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">LangChain \u7528&nbsp;<code>RecursiveCharacterTextSplitter<\/code>\uff08\u9012\u5f52\u5b57\u7b26\u5207\u5206\u5668\uff09\u6765\u5207\u5206\u3002\u5b83\u4f1a\u6309\u7167\u9884\u8bbe\u7684\u5206\u9694\u7b26\uff08\u5148\u6309\u6bb5\u843d\u3001\u518d\u6309\u53e5\u5b50\u3001\u518d\u6309\u5b57\u2026\u2026\uff09\u9012\u5f52\u5730\u628a\u957f\u6587\u672c\u5207\u6210\u5927\u5c0f\u5408\u9002\u7684\u5757\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_text_splitters import RecursiveCharacterTextSplitter\n\n# \u521b\u5efa\u5207\u5206\u5668\nsplitter = RecursiveCharacterTextSplitter(\n    chunk_size=200,        # \u6bcf\u4e2a\u5757\u7684\u76ee\u6807\u5927\u5c0f\uff08\u5b57\u7b26\u6570\uff09\n    chunk_overlap=30,      # \u76f8\u90bb\u5757\u4e4b\u95f4\u7684\u91cd\u53e0\u5b57\u7b26\u6570\n    separators=[\"\\n\\n\", \"\\n\", \"\u3002\", \"\uff1b\", \"\uff0c\", \"\"],  # \u6309\u4f18\u5148\u7ea7\u5c1d\u8bd5\u7684\u5206\u9694\u7b26\n)\n\n# split_documents \u63a5\u6536 Document \u5217\u8868\uff0c\u8fd4\u56de\u5207\u5206\u540e\u7684 Document \u5217\u8868\nchunks = splitter.split_documents(documents)\n\nprint(f\"\u5207\u5206\u6210\u4e86 {len(chunks)} \u4e2a\u5757\")\nfor chunk in chunks[:2]:\n    print(\"---\")\n    print(chunk.page_content)\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4e09\u4e2a\u5173\u952e\u53c2\u6570\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>chunk_size<\/code>\uff1a\u6bcf\u4e2a\u5757\u7684\u76ee\u6807\u5b57\u7b26\u6570\u3002\u592a\u5927\u68c0\u7d22\u4e0d\u7cbe\u51c6\uff0c\u592a\u5c0f\u53c8\u4f1a\u4e22\u5931\u4e0a\u4e0b\u6587\u3002\u8bf7\u5047\u5236\u5ea6\u8fd9\u79cd\u6761\u6b3e\u578b\u6587\u6863\uff0c\u6bcf\u6761\u51e0\u5341\u5230\u4e00\u4e24\u767e\u5b57\uff0c\u8bbe 200 \u6bd4\u8f83\u5408\u9002\u3002<\/li>\n\n\n\n<li><code>chunk_overlap<\/code>\uff1a\u76f8\u90bb\u4e24\u4e2a\u5757<strong>\u91cd\u53e0<\/strong>\u7684\u5b57\u7b26\u6570\u3002\u4e3a\u4ec0\u4e48\u8981\u91cd\u53e0\uff1f\u9632\u6b62\u4e00\u53e5\u8bdd\u6b63\u597d\u88ab\u5207\u65ad\uff0c\u5bfc\u81f4\u4e24\u4e2a\u5757\u90fd\u4e0d\u5b8c\u6574\u3002\u8ba9\u76f8\u90bb\u5757\u5171\u4eab\u4e00\u90e8\u5206\u5185\u5bb9\uff0c\u80fd\u4fdd\u8bc1\u8bed\u4e49\u8fde\u7eed\u3002<\/li>\n\n\n\n<li><code>separators<\/code>\uff1a\u5206\u9694\u7b26\u5217\u8868\uff0c<strong>\u6309\u4f18\u5148\u7ea7\u6392\u5217<\/strong>\u3002\u5207\u5206\u5668\u5148\u7528\u7b2c\u4e00\u4e2a\uff08<code>\\n\\n<\/code>\u00a0\u6bb5\u843d\uff09\u5207\uff0c\u5982\u679c\u5207\u51fa\u6765\u7684\u5757\u8fd8\u662f\u592a\u5927\uff0c\u518d\u7528\u4e0b\u4e00\u4e2a\uff08<code>\\n<\/code>\u00a0\u6362\u884c\uff09\u7ee7\u7eed\u5207\uff0c\u4f9d\u6b64\u7c7b\u63a8\u3002\u8fd9\u6837\u80fd\u5c3d\u91cf\u5728&#8221;\u81ea\u7136\u8fb9\u754c&#8221;\uff08\u6bb5\u843d\u3001\u53e5\u53f7\uff09\u5904\u5207\u65ad\uff0c\u800c\u4e0d\u662f\u4ece\u5b57\u4e2d\u95f4\u786c\u5207\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5207\u5206\u540e\uff0c\u6bcf\u4e2a chunk \u4ecd\u7136\u662f\u4e00\u4e2a&nbsp;<code>Document<\/code>\uff0c\u5e76\u4e14<strong>\u81ea\u52a8\u7ee7\u627f\u4e86\u539f\u6587\u6863\u7684 metadata<\/strong>\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u5411\u91cf\u5316\u5e76\u5b58\u5165\u5411\u91cf\u6570\u636e\u5e93<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u7528&nbsp;<strong>Chroma<\/strong>&nbsp;\u4f5c\u4e3a\u5411\u91cf\u6570\u636e\u5e93\u6765\u5b58\u50a8\u5411\u91cf\u3002\u6211\u4eec\u8fd9\u91cc\u8fde\u63a5\u7684\u662f<strong>\u90e8\u7f72\u5728\u8fdc\u7a0b\u670d\u52a1\u5668\u4e0a\u7684 Chroma \u670d\u52a1<\/strong>\uff0c\u6240\u4ee5\u8981\u901a\u8fc7&nbsp;<code>host<\/code>&nbsp;\u548c&nbsp;<code>port<\/code>&nbsp;\u6307\u5b9a\u5b83\u7684\u5730\u5740<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_openai import OpenAIEmbeddings\nfrom langchain_chroma import Chroma\n\n# 1. \u521b\u5efa\u5d4c\u5165\u6a21\u578b\uff08\u8d1f\u8d23\u628a\u6587\u672c\u8f6c\u6210\u5411\u91cf\uff09\nembeddings = OpenAIEmbeddings(\n    model=\"text-embedding-v3\",     # \u5d4c\u5165\u6a21\u578b\u540d\n    api_key=\"\u4f60\u7684API Key\",\n    base_url=\"https:\/\/dashscope.aliyuncs.com\/compatible-mode\/v1\",\n)\n\n# 2. \u628a\u6240\u6709 chunk \u5411\u91cf\u5316\u5e76\u5b58\u5165 Chroma\n#    from_documents \u5185\u90e8\u4f1a\uff1a\u2460 \u5bf9\u6bcf\u4e2achunk\u8c03\u7528embeddings\u8f6c\u6210\u5411\u91cf\n#                          \u2461 \u628a(\u5411\u91cf, \u6587\u672c, metadata)\u4e00\u8d77\u5b58\u8fdbChroma\nvector_store = Chroma.from_documents(\n    documents=chunks,              # \u4e0a\u4e00\u6b65\u5207\u5206\u597d\u7684\u5757\n    embedding=embeddings,          # \u5d4c\u5165\u6a21\u578b\n    collection_name=\"leave_policy\",# \u96c6\u5408\u540d\uff08\u7c7b\u4f3c\u6570\u636e\u5e93\u7684\u8868\u540d\uff09\n    host=\"192.168.1.100\",          # \u8fdc\u7a0b Chroma \u670d\u52a1\u7684\u5730\u5740\n    port=8000,                     # \u8fdc\u7a0b Chroma \u670d\u52a1\u7684\u7aef\u53e3\n)\n\nprint(\"\u77e5\u8bc6\u5e93\u6784\u5efa\u5b8c\u6210\uff01\")\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6267\u884c\u5b8c\u540e\uff0c\u6574\u4efd\u8bf7\u5047\u5236\u5ea6\u5c31\u88ab\u5207\u6210\u82e5\u5e72\u5c0f\u5757\u3001\u8f6c\u6210\u5411\u91cf\u3001\u5b58\u8fdb<strong>\u8fdc\u7a0b\u7684<\/strong>&nbsp;Chroma \u670d\u52a1\u91cc\u4e86\u3002<strong>\u6784\u5efa\u9636\u6bb5\u5230\u6b64\u7ed3\u675f<\/strong>\u2014\u2014\u8fd9\u4e00\u6b65\u662f\u79bb\u7ebf\u7684\uff0c\u53ea\u9700\u505a\u4e00\u6b21\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u68c0\u7d22<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u6784\u5efa\u597d\u77e5\u8bc6\u5e93\u540e\uff0c\u5c31\u53ef\u4ee5\u6839\u636e\u7528\u6237\u95ee\u9898\u68c0\u7d22\u76f8\u5173\u5185\u5bb9\u4e86\u3002\u8fd9\u662f\u6700\u57fa\u7840\u7684\u68c0\u7d22\u2014\u2014<strong>\u76f8\u4f3c\u5ea6\u68c0\u7d22<\/strong>\uff1a\u628a\u7528\u6237\u95ee\u9898\u4e5f\u8f6c\u6210\u5411\u91cf\uff0c\u5728 Chroma \u91cc\u627e\u5411\u91cf\u6700\u63a5\u8fd1\u7684\u51e0\u4e2a\u5757\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u8fde\u63a5\u5230\u5df2\u6784\u5efa\u597d\u7684\u5411\u91cf\u5e93\uff08\u5982\u679c\u662f\u65b0\u8fdb\u7a0b\uff0c\u91cd\u65b0\u8fde\u4e00\u6b21\uff09\nvector_store = Chroma(\n    collection_name=\"leave_policy\",\n    embedding_function=embeddings,\n    host=\"192.168.1.100\",          # \u8fdc\u7a0b Chroma \u670d\u52a1\u7684\u5730\u5740\n    port=8000,                     # \u8fdc\u7a0b Chroma \u670d\u52a1\u7684\u7aef\u53e3\n)\n\n# \u7528 similarity_search \u505a\u76f8\u4f3c\u5ea6\u68c0\u7d22\n# k=2 \u8868\u793a\u8fd4\u56de\u6700\u76f8\u5173\u7684 2 \u4e2a\u5757\nquestion = \"\u4e8b\u5047\u4e00\u5e74\u6700\u591a\u80fd\u8bf7\u591a\u5c11\u5929\uff1f\"\nresults = vector_store.similarity_search(question, k=2)\n\nfor doc in results:\n    print(\"---\")\n    print(doc.page_content)\n# \u4f1a\u68c0\u7d22\u51fa\u5305\u542b\"\u7b2c\u5341\u4e09\u6761 \u4e8b\u5047\u6bcf\u6708\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc73\u5929\uff0c\u5168\u5e74\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc715\u5929\"\u7684\u90a3\u4e2a\u5757\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>similarity_search(question, k=2)<\/code>&nbsp;\u505a\u7684\u4e8b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u628a\u00a0<code>question<\/code>\u00a0\u7528\u5d4c\u5165\u6a21\u578b\u8f6c\u6210\u5411\u91cf<\/li>\n\n\n\n<li>\u5728 Chroma \u4e2d\u627e\u51fa\u5411\u91cf\u8ddd\u79bb\u6700\u8fd1\u7684\u00a0<code>k<\/code>\u00a0\u4e2a chunk<\/li>\n\n\n\n<li>\u8fd4\u56de\u8fd9\u4e9b chunk\uff08<code>Document<\/code>\u00a0\u5217\u8868\uff09<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u66f4\u5e38\u7528\u7684\u5199\u6cd5\uff1a\u628a\u5411\u91cf\u5e93\u53d8\u6210&#8221;\u68c0\u7d22\u5668\uff08Retriever\uff09&#8221;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u540e\u9762\u80fd\u628a\u68c0\u7d22\u63a5\u5165\u94fe\uff08Chain\uff09\uff0c\u901a\u5e38\u628a\u5411\u91cf\u5e93\u8f6c\u6210\u4e00\u4e2a&nbsp;<code>retriever<\/code>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# as_retriever \u628a\u5411\u91cf\u5e93\u5305\u88c5\u6210\u4e00\u4e2a Runnable\uff0c\u53ef\u4ee5\u53c2\u4e0e\u94fe\nretriever = vector_store.as_retriever(search_kwargs={\"k\": 2})\n\n# retriever \u4e5f\u6709 invoke \u65b9\u6cd5\uff0c\u4f20\u5165\u95ee\u9898\uff0c\u8fd4\u56de\u76f8\u5173 Document \u5217\u8868\ndocs = retriever.invoke(\"\u4e8b\u5047\u4e00\u5e74\u6700\u591a\u80fd\u8bf7\u591a\u5c11\u5929\uff1f\")\n```<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e0a\u4e0b\u6587\u6ce8\u5165<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u68c0\u7d22\u62ff\u5230\u76f8\u5173\u5185\u5bb9\u540e\uff0c\u4e0b\u4e00\u6b65\u662f\u628a\u8fd9\u4e9b\u5185\u5bb9&#8221;\u6ce8\u5165&#8221;\u5230\u63d0\u793a\u8bcd\u91cc\u53d1\u7ed9\u6a21\u578b\u2014\u2014\u8fd9\u4e00\u6b65\u53eb<strong>\u4e0a\u4e0b\u6587\u6ce8\u5165<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u5148\u5728\u63d0\u793a\u8bcd\u91cc\u7559\u4e00\u4e2a&nbsp;<code>{context}<\/code>&nbsp;\u5360\u4f4d\u7b26\uff0c\u4e13\u95e8\u7528\u6765\u653e\u68c0\u7d22\u5230\u7684\u5185\u5bb9\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_core.prompts import ChatPromptTemplate\nfrom langchain_core.output_parsers import StrOutputParser\n\n# \u63d0\u793a\u8bcd\uff1a\u68c0\u7d22\u5230\u7684\u5185\u5bb9\u653e\u8fdb {context}\uff0c\u7528\u6237\u95ee\u9898\u653e\u8fdb {question}\nprompt = ChatPromptTemplate.from_messages([\n    (\"system\", \"\"\"\u4f60\u662f\u516c\u53f8HR\u52a9\u624b\uff0c\u8bf7\u4e25\u683c\u6839\u636e\u4e0b\u9762\u63d0\u4f9b\u7684\u5236\u5ea6\u5185\u5bb9\u56de\u7b54\u5458\u5de5\u95ee\u9898\u3002\n\u5982\u679c\u5236\u5ea6\u5185\u5bb9\u91cc\u6ca1\u6709\u76f8\u5173\u89c4\u5b9a\uff0c\u5c31\u5982\u5b9e\u8bf4\"\u5236\u5ea6\u4e2d\u672a\u63d0\u53ca\"\uff0c\u4e0d\u8981\u7f16\u9020\u3002\n\n\u5236\u5ea6\u5185\u5bb9\uff1a\n{context}\"\"\"),\n    (\"human\", \"{question}\"),\n])\n\nllm = ChatOpenAI(model=\"qwen-plus\", api_key=\"...\", base_url=\"...\")\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u6709\u4e2a\u7ec6\u8282\u8981\u6ce8\u610f\uff1a<code>retriever.invoke(question)<\/code>&nbsp;\u8fd4\u56de\u7684\u662f\u4e00\u4e2a&nbsp;<strong><code>Document<\/code>&nbsp;\u5217\u8868<\/strong>\uff0c\u800c\u63d0\u793a\u8bcd\u91cc\u7684&nbsp;<code>{context}<\/code>&nbsp;\u9700\u8981\u7684\u662f\u4e00\u6bb5<strong>\u7eaf\u6587\u672c<\/strong>\u3002\u6240\u4ee5\u4e2d\u95f4\u8981\u81ea\u5df1\u5199\u4e00\u6b65&#8221;\u628a Document \u5217\u8868\u62fc\u6210\u6587\u672c&#8221;\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u624b\u52a8\u5199\u4e00\u4e2a\u51fd\u6570\uff0c\u628a Document \u5217\u8868\u62fc\u6210\u7eaf\u6587\u672c\ndef format_docs(docs) -&gt; str:\n    # \u53d6\u51fa\u6bcf\u4e2a Document \u7684\u6b63\u6587 page_content\uff0c\u7528\u7a7a\u884c\u62fc\u63a5\u8d77\u6765\n    return \"\\n\\n\".join(doc.page_content for doc in docs)\n\ndef answer(question: str) -&gt; str:\n    # \u2460 \u68c0\u7d22\uff1a\u62ff\u5230 Document \u5217\u8868\n    docs = retriever.invoke(question)\n    # \u2461 \u6ce8\u5165\uff1a\u628a Document \u5217\u8868\u62fc\u6210\u6587\u672c\uff0c\u586b\u8fdb {context}\n    context = format_docs(docs)\n    # \u2462 \u56de\u7b54\uff1a\u8c03\u7528\u94fe\n    chain = prompt | llm | StrOutputParser()\n    return chain.invoke({\"context\": context, \"question\": question})\n\n# \u6d4b\u8bd5\nprint(answer(\"\u4e8b\u5047\u4e00\u5e74\u6700\u591a\u80fd\u8bf7\u591a\u5c11\u5929\uff1f\"))\n# \u8f93\u51fa\u7c7b\u4f3c\uff1a\"\u6839\u636e\u5236\u5ea6\u7b2c\u5341\u4e09\u6761\uff0c\u4e8b\u5047\u6bcf\u6708\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc73\u5929\uff0c\u5168\u5e74\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc715\u5929\u3002\"\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u6837\u6574\u4e2a RAG \u95ed\u73af\u5c31\u8dd1\u901a\u4e86\uff1a\u68c0\u7d22 \u2192 \u62fc\u6210\u6587\u672c\u6ce8\u5165 \u2192 \u6a21\u578b\u56de\u7b54\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f46\u8fd9\u91cc\u6709\u4e24\u5904\u662f\u6211\u4eec&#8221;\u624b\u52a8&#8221;\u5728\u505a\u7684\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u624b\u52a8\u8c03\u7528\u00a0<code>retriever.invoke(question)<\/code>\u00a0\u68c0\u7d22<\/li>\n\n\n\n<li>\u624b\u52a8\u5199\u00a0<code>format_docs<\/code>\u00a0\u628a Document \u5217\u8868\u62fc\u6210\u6587\u672c<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u4e00\u8282\u6211\u4eec\u7528 LangChain \u63d0\u4f9b\u7684\u5de5\u5177\uff0c\u628a\u8fd9\u4e24\u6b65\u90fd\u81ea\u52a8\u5316\uff0c\u4e32\u6210\u4e00\u6761\u5b8c\u6574\u7684\u94fe\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u81ea\u52a8\u68c0\u7d22\u4e0e\u6ce8\u5165<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">create_stuff_documents_chain \u81ea\u52a8\u62fc\u63a5\u6587\u6863<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">LangChain \u63d0\u4f9b\u4e86\u4e00\u4e2a\u73b0\u6210\u7684\u5de5\u5177\u628a Document \u5217\u8868\u62fc\u6210\u6587\u672c\u518d\u586b\u8fdb\u63d0\u793a\u8bcd\u7684&nbsp;<code>{context}<\/code>\uff0c\u8fd9\u4e2a\u5de5\u5177\u5c31\u662f\u2014\u2014<code>create_stuff_documents_chain<\/code>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>create_stuff_documents_chain<\/code>&nbsp;\u4f1a\u521b\u5efa\u4e00\u4e2a\u94fe\uff0c\u5b83\u7684\u4f5c\u7528\u662f\uff1a<strong>\u63a5\u6536\u4e00\u4e2a&nbsp;<code>Document<\/code>&nbsp;\u5217\u8868\uff0c\u81ea\u52a8\u628a\u5b83\u4eec\u62fc\u6210\u6587\u672c\uff0c\u586b\u8fdb\u63d0\u793a\u8bcd\u7684\u5360\u4f4d\u7b26\uff0c\u518d\u8c03\u7528\u6a21\u578b\u3002<\/strong>\uff08&#8221;stuff&#8221; \u5c31\u662f&#8221;\u628a\u6240\u6709\u6587\u6863\u4e00\u80a1\u8111\u585e\u8fdb\u4e0a\u4e0b\u6587&#8221;\u7684\u610f\u601d\u3002\uff09<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain.chains.combine_documents import create_stuff_documents_chain\n\n# \u521b\u5efa\u6587\u6863\u94fe\ndocument_chain = create_stuff_documents_chain(\n    llm,                              # \u7528\u54ea\u4e2a\u6a21\u578b\u6765\u56de\u7b54\n    prompt,                           # \u63d0\u793a\u8bcd\u6a21\u677f\n    document_variable_name=\"context\", # \u89c1\u4e0b\u65b9\u8bf4\u660e\n)\n\n# \u8c03\u7528\uff1acontext \u76f4\u63a5\u4f20 Document \u5217\u8868\uff08\u4e0d\u7528\u81ea\u5df1\u62fc\u6587\u672c\u4e86\uff09\uff0c\u5b83\u4f1a\u81ea\u52a8\u62fc\u63a5\u5e76\u6ce8\u5165\ndocs = retriever.invoke(\"\u4e8b\u5047\u4e00\u5e74\u6700\u591a\u80fd\u8bf7\u591a\u5c11\u5929\uff1f\")   # \u624b\u52a8\u68c0\u7d22\uff0c\u62ff\u5230 Document \u5217\u8868\nresult = document_chain.invoke({\n    \"context\": docs          # \u76f4\u63a5\u4f20 Document \u5217\u8868\uff01\n})\nprint(result)\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u6bd4\u4e0a\u4e00\u8282\uff1a\u4e4b\u524d&nbsp;<code>{context}<\/code>&nbsp;\u8981\u586b<strong>\u6211\u4eec&nbsp;<code>format_docs<\/code>&nbsp;\u62fc\u597d\u7684\u5b57\u7b26\u4e32<\/strong>\uff0c\u73b0\u5728&nbsp;<code>context<\/code>&nbsp;\u76f4\u63a5\u4f20&nbsp;<strong>Document \u5217\u8868<\/strong>\uff0c\u62fc\u63a5\u4ea4\u7ed9&nbsp;<code>create_stuff_documents_chain<\/code>&nbsp;\u81ea\u52a8\u5b8c\u6210\uff0c<code>format_docs<\/code>&nbsp;\u4e0d\u7528\u6211\u4eec\u81ea\u5df1\u5199\u4e86\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u70b9\u89e3\u91ca&nbsp;<code>document_variable_name<\/code>&nbsp;\u8fd9\u4e2a\u53c2\u6570\u3002<\/strong>&nbsp;\u7ed3\u5408\u4e0a\u9762\u7684\u8c03\u7528\u4ee3\u7801&nbsp;<code>invoke({\"context\": docs, ...})<\/code>&nbsp;\u6765\u770b\uff0c\u5b83\u5176\u5b9e<strong>\u540c\u65f6\u627f\u62c5\u4e86\u4e24\u4e2a\u4f5c\u7528<\/strong>\uff08\u7528\u7684\u662f\u540c\u4e00\u4e2a\u540d\u5b57&nbsp;<code>context<\/code>\uff09\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u8bfb\u53d6<\/strong>\uff1a\u544a\u8bc9\u00a0<code>create_stuff_documents_chain<\/code>\u00a0\u4ece\u8f93\u5165\u5b57\u5178\u7684<strong>\u54ea\u4e2a key<\/strong>\u00a0\u91cc\u53d6\u51fa Document \u5217\u8868\u3002\u6211\u4eec\u8bbe\u7684\u662f\u00a0<code>\"context\"<\/code>\uff0c\u6240\u4ee5\u5b83\u5c31\u53bb\u00a0<code>invoke<\/code>\u00a0\u4f20\u5165\u7684\u5b57\u5178\u91cc\u627e\u00a0<code>context<\/code>\u00a0\u8fd9\u4e2a key\uff0c\u628a\u5b83\u7684\u503c\uff08<code>docs<\/code>\uff0c\u4e00\u4e2a Document \u5217\u8868\uff09\u62ff\u51fa\u6765\u3002<\/li>\n\n\n\n<li><strong>\u5199\u5165<\/strong>\uff1a\u628a\u62ff\u5230\u7684 Document \u5217\u8868\u62fc\u6210\u6587\u672c\u540e\uff0c\u586b\u5230\u63d0\u793a\u8bcd\u91cc<strong>\u540c\u540d\u7684\u5360\u4f4d\u7b26<\/strong>\u00a0<code>{context}<\/code>\u3002<\/li>\n<\/ol>\n\n\n\n<h4 class=\"wp-block-heading\">RunnablePassthrough.assign \u81ea\u52a8\u68c0\u7d22<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u867d\u7136&nbsp;<code>document_chain<\/code>&nbsp;\u5e2e\u6211\u4eec\u81ea\u52a8\u62fc\u63a5\u4e86\u6587\u6863\uff0c\u4f46&nbsp;<code>docs = retriever.invoke(...)<\/code>&nbsp;\u8fd9\u6b65<strong>\u68c0\u7d22\u8fd8\u662f\u624b\u52a8\u7684<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u5e0c\u671b\u7684\u662f\uff1a\u8c03\u7528\u65f6<strong>\u53ea\u4f20\u7528\u6237\u95ee\u9898<\/strong>\uff0c\u68c0\u7d22\u8fd9\u4e00\u6b65\u4e5f\u81ea\u52a8\u5b8c\u6210\u3002\u8fd9\u5c31\u8981\u7528\u5230\u524d\u9762&#8221;\u94fe&#8221;\u5c0f\u8282\u8bb2\u8fc7\u7684&nbsp;<code>RunnablePassthrough.assign<\/code>\u2014\u2014\u5b83\u80fd\u5728\u539f\u8f93\u5165\u5b57\u5178\u7684\u57fa\u7840\u4e0a<strong>\u65b0\u589e\u4e00\u4e2a\u5b57\u6bb5<\/strong>\uff08key \u662f\u53c2\u6570\u540d\uff0cvalue \u662f\u53f3\u8fb9 Runnable \u7684\u8fd0\u884c\u7ed3\u679c\uff0c\u539f\u6709\u5b57\u6bb5\u539f\u6837\u4fdd\u7559\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u56de\u5230 RAG\uff0c\u6211\u4eec\u6b63\u597d\u53ef\u4ee5\u7528\u5b83\u7ed9\u8f93\u5165\u5b57\u5178<strong>\u81ea\u52a8\u8865\u4e0a&nbsp;<code>context<\/code>&nbsp;\u5b57\u6bb5<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\nfrom langchain_core.runnables import RunnablePassthrough\n\n# \u68c0\u7d22\u5668\u63a5\u6536\u7684\u662f\u5b57\u7b26\u4e32\u95ee\u9898\uff0c\u4f46\u6211\u4eec\u7684\u8f93\u5165\u662f {\"question\": \"...\"} \u5b57\u5178\n# \u6240\u4ee5\u5148\u4ece\u5b57\u5178\u91cc\u53d6\u51fa question \u518d\u4ea4\u7ed9 retriever\nretrieve_docs = (lambda x: x[\"question\"]) | retriever\n\n# assign(context=retrieve_docs) \u7684\u542b\u4e49\uff1a\n#   - \u65b0\u589e\u7684 key \u662f \"context\"\uff08\u7b49\u53f7\u5de6\u8fb9\u7684\u53c2\u6570\u540d\uff09\n#   - value \u662f retrieve_docs \u8fd0\u884c\u540e\u7684\u8fd4\u56de\u503c\uff08\u5373\u68c0\u7d22\u5230\u7684 Document \u5217\u8868\uff09\n#   - \u539f\u6709\u7684 question \u5b57\u6bb5\u539f\u6837\u4fdd\u7559\nrag_chain = RunnablePassthrough.assign(context=retrieve_docs) | document_chain\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u6761\u94fe\u7684\u6570\u636e\u6d41\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n\u8c03\u7528 rag_chain.invoke({\"question\": \"\u4e8b\u5047\u4e00\u5e74\u6700\u591a\u80fd\u8bf7\u591a\u5c11\u5929\uff1f\"})\n   \u2193\nRunnablePassthrough.assign(context=retrieve_docs)\n   \u2193 \u53d6\u51fa question \u2192 \u4ea4\u7ed9 retriever \u68c0\u7d22 \u2192 \u5f97\u5230 Document \u5217\u8868\n   \u2193 \u628a Document \u5217\u8868\u4f5c\u4e3a context \u52a0\u8fdb\u5b57\u5178\uff0cquestion \u539f\u6837\u4fdd\u7559\n   \u2193 \u5b57\u5178\u53d8\u4e3a {\"question\": \"...\", \"context\": [Document, Document]}\ndocument_chain\n   \u2193 \u81ea\u52a8\u628a context\uff08Document\u5217\u8868\uff09\u62fc\u6210\u6587\u672c\u586b\u8fdb {context} \u5360\u4f4d\u7b26\n   \u2193 \u8c03\u7528\u6a21\u578b\u56de\u7b54\n\u6700\u7ec8\u8f93\u51fa\uff1a\u6a21\u578b\u7684\u56de\u7b54\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ce8\u610f&nbsp;<code>assign<\/code>&nbsp;\u7684\u7cbe\u5999\u4e4b\u5904\uff1a\u5b83<strong>\u4fdd\u7559\u4e86\u539f\u6709\u7684&nbsp;<code>question<\/code>&nbsp;\u5b57\u6bb5<\/strong>\uff0c\u540c\u65f6<strong>\u65b0\u589e\u4e86&nbsp;<code>context<\/code>&nbsp;\u5b57\u6bb5<\/strong>\u3002\u8fd9\u6837\u6700\u7ec8\u4f20\u7ed9&nbsp;<code>document_chain<\/code>&nbsp;\u7684\u5b57\u5178\u91cc\uff0c<code>question<\/code>&nbsp;\u548c&nbsp;<code>context<\/code>&nbsp;\u90fd\u9f50\u4e86\u2014\u2014\u800c\u6211\u4eec\u8c03\u7528\u65f6\u53ea\u4f20\u4e86&nbsp;<code>question<\/code>\uff0c<code>context<\/code>&nbsp;\u662f\u81ea\u52a8\u68c0\u7d22\u8865\u4e0a\u7684\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6d4b\u8bd5\u6548\u679c\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">```\n# \u8c03\u7528\u65f6\u53ea\u4f20 question\uff0c\u68c0\u7d22\u548c\u6ce8\u5165\u5168\u81ea\u52a8\nprint(rag_chain.invoke({\"question\": \"\u4e8b\u5047\u4e00\u5e74\u6700\u591a\u80fd\u8bf7\u591a\u5c11\u5929\uff1f\"}))\n# \u8f93\u51fa\u7c7b\u4f3c\uff1a\"\u6839\u636e\u5236\u5ea6\u7b2c\u5341\u4e09\u6761\uff0c\u4e8b\u5047\u6bcf\u6708\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc73\u5929\uff0c\u5168\u5e74\u7d2f\u8ba1\u4e0d\u5f97\u8d85\u8fc715\u5929\u3002\"\n\nprint(rag_chain.invoke({\"question\": \"\u8bf75\u5929\u5047\u9700\u8981\u8c01\u5ba1\u6279\uff1f\"}))\n# \u8f93\u51fa\u7c7b\u4f3c\uff1a\"\u6839\u636e\u5236\u5ea6\u7b2c\u4e8c\u5341\u6761\uff0c\u8bf7\u50473\u5929\u4ee5\u4e0a\u7531\u90e8\u95e8\u8d1f\u8d23\u4eba\u548c\u4eba\u529b\u8d44\u6e90\u90e8\u5171\u540c\u5ba1\u6279\u3002\"\n\nprint(rag_chain.invoke({\"question\": \"\u516c\u53f8\u6709\u6ca1\u6709\u56e2\u5efa\u7ecf\u8d39\uff1f\"}))\n# \u8f93\u51fa\u7c7b\u4f3c\uff1a\"\u5236\u5ea6\u4e2d\u672a\u63d0\u53ca\u3002\"\uff08\u56e0\u4e3a\u8bf7\u5047\u5236\u5ea6\u91cc\u786e\u5b9e\u6ca1\u6709\u8fd9\u6761\uff0c\u6a21\u578b\u4e0d\u4f1a\u778e\u7f16\uff09\n```<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u81f3\u6b64\uff0c\u6574\u4e2a RAG \u88ab\u4e32\u6210\u4e86\u4e00\u6761\u5b8c\u6574\u7684\u94fe\uff1a\u4f20\u5165\u95ee\u9898 \u2192 \u81ea\u52a8\u68c0\u7d22 \u2192 \u81ea\u52a8\u62fc\u63a5\u6ce8\u5165\u4e0a\u4e0b\u6587 \u2192 \u6a21\u578b\u56de\u7b54\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u56de\u987e\u6574\u4e2a\u6d41\u7a0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">\u9636\u6bb5<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u6b65\u9aa4<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u7528\u5230\u7684\u7ec4\u4ef6<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\">\u6784\u5efa\uff08\u79bb\u7ebf\uff09<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u52a0\u8f7d\u6587\u6863<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>TextLoader<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u6784\u5efa\uff08\u79bb\u7ebf\uff09<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u5207\u5206\u6587\u6863<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>RecursiveCharacterTextSplitter<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u6784\u5efa\uff08\u79bb\u7ebf\uff09<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u5411\u91cf\u5316\u5165\u5e93<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>OpenAIEmbeddings<\/code>&nbsp;+&nbsp;<code>Chroma<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u68c0\u7d22\uff08\u5728\u7ebf\uff09<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u76f8\u4f3c\u5ea6\u68c0\u7d22<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>vector_store.as_retriever()<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u68c0\u7d22\uff08\u5728\u7ebf\uff09<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6587\u6863\u62fc\u63a5+\u6ce8\u5165<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>create_stuff_documents_chain<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u68c0\u7d22\uff08\u5728\u7ebf\uff09<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u81ea\u52a8\u68c0\u7d22\u4e32\u8054<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>RunnablePassthrough.assign<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u5c31\u662f RAG \u6700\u6838\u5fc3\u7684\u9aa8\u67b6\u3002\u5b9e\u9645\u9879\u76ee\u4e2d\u8fd8\u4f1a\u6709\u5f88\u591a\u589e\u5f3a\uff08\u67e5\u8be2\u91cd\u5199\u3001\u91cd\u6392\u5e8f\u3001\u6df7\u5408\u68c0\u7d22\u7b49\uff09\uff0c\u4f46\u90fd\u662f\u5728\u8fd9\u4e2a\u57fa\u7840\u9aa8\u67b6\u4e0a\u505a\u7684\u6269\u5c55\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>LangChain \u7b80\u4ecb LangChain \u662f\u4e00\u4e2a\u7528\u4e8e\u5f00\u53d1\u5927\u8bed\u8a00\u6a21\u578b\u5e94\u7528\u7684\u6846\u67b6\u3002\u5b83\u63d0\u4f9b\u4e86\uff1a \u5b89\u88c5\u4f9d\u8d56\uff1a &#8220; [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[10],"class_list":["post-740","post","type-post","status-publish","format-standard","hentry","category-learn","tag-ai"],"_links":{"self":[{"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/posts\/740","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/comments?post=740"}],"version-history":[{"count":1,"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/posts\/740\/revisions"}],"predecessor-version":[{"id":741,"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/posts\/740\/revisions\/741"}],"wp:attachment":[{"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/media?parent=740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/categories?post=740"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/larkdrop.cafe\/index.php\/wp-json\/wp\/v2\/tags?post=740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}