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| 1 | +# 01-从0到1搭建一个基于FastAPI的智能聊天机器人应用 |
| 2 | + |
| 3 | +```txt |
| 4 | +fastapi==0.108.0 |
| 5 | +langchain_core==0.1.28 |
| 6 | +langchain_openai == 0.0.5 |
| 7 | +langchain_community==0.0.25 |
| 8 | +langchain==0.1.10 |
| 9 | +redis==7.2.0 |
| 10 | +qdrant_client == 1.7.1 |
| 11 | +uvicorn==0.23.2 |
| 12 | +``` |
| 13 | + |
| 14 | + |
| 15 | + |
| 16 | +```bash |
| 17 | +pip install -r requirements.txt |
| 18 | +``` |
| 19 | + |
| 20 | + |
| 21 | + |
| 22 | + |
| 23 | + |
| 24 | +想检查某依赖是否安装完毕: |
| 25 | + |
| 26 | +``` |
| 27 | +pip show fastapi |
| 28 | +``` |
| 29 | + |
| 30 | + |
| 31 | + |
| 32 | +那就先引入 fastapi。 |
| 33 | + |
| 34 | +```python |
| 35 | +# 这是一个使用 FastAPI 框架编写的简单应用程序的示例。 |
| 36 | +# 导入FastAPI模块 |
| 37 | +from fastapi import FastAPI |
| 38 | + |
| 39 | +# 创建一个FastAPI应用实例 |
| 40 | +app = FastAPI() |
| 41 | + |
| 42 | + |
| 43 | +# 定义一个路由,当访问'/'时会被触发 |
| 44 | +@app.get("/") |
| 45 | +# 定义一个函数,返回一个字典,key为"Hello",value为"World" |
| 46 | +def read_root(): |
| 47 | + return {"Hello": "World"} |
| 48 | + |
| 49 | + |
| 50 | +# 如果主程序为 __main__,则启动服务器 |
| 51 | +if __name__ == "__main__": |
| 52 | + import uvicorn |
| 53 | + |
| 54 | + uvicorn.run(app, host="localhost", port=8090) |
| 55 | +``` |
| 56 | + |
| 57 | +如何运行呢? |
| 58 | + |
| 59 | + |
| 60 | + |
| 61 | +直接点击它: |
| 62 | + |
| 63 | + |
| 64 | + |
| 65 | +[直达API文档](http://localhost:8090/docs): |
| 66 | + |
| 67 | + |
| 68 | + |
| 69 | +新增一个 chat 接口: |
| 70 | + |
| 71 | +```python |
| 72 | +# 这是一个使用 FastAPI 框架编写的简单应用程序的示例。 |
| 73 | +# 导入FastAPI模块 |
| 74 | +from fastapi import FastAPI, BackgroundTasks |
| 75 | + |
| 76 | +# 创建一个FastAPI应用实例 |
| 77 | +app = FastAPI() |
| 78 | + |
| 79 | + |
| 80 | +# 定义一个路由,当访问'/'时会被触发 |
| 81 | +@app.get("/") |
| 82 | +# 定义一个函数,返回一个字典,key为"Hello",value为"World" |
| 83 | +def read_root(): |
| 84 | + return {"Hello": "World"} |
| 85 | + |
| 86 | + |
| 87 | +@app.post("/chat") |
| 88 | +def chat(): |
| 89 | + return {"response": "I am a chat bot!"} |
| 90 | + |
| 91 | + |
| 92 | +# 如果主程序为 __main__,则启动服务器 |
| 93 | +if __name__ == "__main__": |
| 94 | + import uvicorn |
| 95 | + |
| 96 | + uvicorn.run(app, host="localhost", port=8090) |
| 97 | +``` |
| 98 | + |
| 99 | +API文档立即更新: |
| 100 | + |
| 101 | + |
| 102 | + |
| 103 | +同理,我们编写ws函数: |
| 104 | + |
| 105 | +```python |
| 106 | +@app.websocket("/ws") |
| 107 | +async def websocket_endpoint(websocket: WebSocket): |
| 108 | + await websocket.accept() |
| 109 | + try: |
| 110 | + while True: |
| 111 | + data = await websocket.receive_text() |
| 112 | + await websocket.send_text(f"Message text was: {data}") |
| 113 | + except WebSocketDisconnect: |
| 114 | + print("Connection closed") |
| 115 | + await websocket.close() |
| 116 | +``` |
| 117 | + |
| 118 | +使用 postman 构造 websocket 请求: |
| 119 | + |
| 120 | + |
| 121 | + |
| 122 | +先点击 connect,再输入要发送的消息:你好。点击 send 即请求,响应了你好! |
| 123 | + |
| 124 | + |
| 125 | + |
| 126 | +## 完整代码 |
| 127 | + |
| 128 | +```python |
| 129 | +# 这是一个使用 FastAPI 框架编写的简单应用程序的示例。 |
| 130 | +# 导入FastAPI模块 |
| 131 | +import os |
| 132 | + |
| 133 | +from dotenv import load_dotenv, find_dotenv |
| 134 | +from fastapi import FastAPI, WebSocket, WebSocketDisconnect, BackgroundTasks |
| 135 | +from langchain_openai import ChatOpenAI |
| 136 | +from langchain.agents import create_openai_tools_agent, AgentExecutor, tool |
| 137 | +from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder |
| 138 | +from langchain.schema import StrOutputParser |
| 139 | +from langchain.memory import ConversationTokenBufferMemory |
| 140 | +from langchain_community.chat_message_histories import RedisChatMessageHistory |
| 141 | +from langchain_community.document_loaders import WebBaseLoader |
| 142 | +from langchain.text_splitter import RecursiveCharacterTextSplitter |
| 143 | +import os |
| 144 | +import asyncio |
| 145 | +import uuid |
| 146 | +from langchain_community.vectorstores import Qdrant |
| 147 | +from qdrant_client import QdrantClient |
| 148 | +from Mytools import * |
| 149 | + |
| 150 | +# 设置 API 密钥 |
| 151 | +DASHSCOPE_API_KEY = "xxx" |
| 152 | +load_dotenv(find_dotenv()) |
| 153 | +os.environ["DASHSCOPE_API_KEY"] = DASHSCOPE_API_KEY |
| 154 | +os.environ["SERPAPI_API_KEY"] = "xxx" |
| 155 | + |
| 156 | +# 创建一个FastAPI应用实例 |
| 157 | +app = FastAPI() |
| 158 | + |
| 159 | + |
| 160 | +# 定义一个工具函数 |
| 161 | +@tool |
| 162 | +def test(): |
| 163 | + """ Test tool""""" |
| 164 | + return "test" |
| 165 | + |
| 166 | + |
| 167 | +# 定义一个Master类 |
| 168 | +class Master: |
| 169 | + def __init__(self): |
| 170 | + # 初始化ChatOpenAI模型 |
| 171 | + self.chatmodel = ChatOpenAI( |
| 172 | + api_key=os.getenv("DASHSCOPE_API_KEY"), |
| 173 | + base_url="https://dashscope.aliyuncs.com/compatible-mode/v1", |
| 174 | + model="qwen-plus", |
| 175 | + temperature=0, |
| 176 | + streaming=True, |
| 177 | + ) |
| 178 | + # 设置记忆存储键名 |
| 179 | + self.MEMORY_KEY = "chat_history" |
| 180 | + # 初始化系统提示模板 |
| 181 | + self.SYSTEMPL = "" |
| 182 | + self.prompt = ChatPromptTemplate.from_messages( |
| 183 | + [ |
| 184 | + ( |
| 185 | + "system", |
| 186 | + "你是一个助手" |
| 187 | + ), |
| 188 | + ( |
| 189 | + "user", |
| 190 | + "{input}" |
| 191 | + ), |
| 192 | + MessagesPlaceholder(variable_name="agent_scratchpad"), |
| 193 | + ], |
| 194 | + ) |
| 195 | + # 初始化记忆存储 |
| 196 | + self.memory = "" |
| 197 | + # 初始化工具列表 |
| 198 | + tools = [test] |
| 199 | + # 创建OpenAI工具代理 |
| 200 | + agent = create_openai_tools_agent( |
| 201 | + self.chatmodel, |
| 202 | + tools=tools, |
| 203 | + prompt=self.prompt, |
| 204 | + ) |
| 205 | + # 创建代理执行器 |
| 206 | + self.agent_executor = AgentExecutor( |
| 207 | + agent=agent, |
| 208 | + tools=tools, |
| 209 | + verbose=True, |
| 210 | + ) |
| 211 | + |
| 212 | + # 定义运行方法 |
| 213 | + def run(self, query): |
| 214 | + # 调用代理执行器并获取结果 |
| 215 | + result = self.agent_executor.invoke({"input": query}) |
| 216 | + # 返回执行器的响应 |
| 217 | + return result |
| 218 | + |
| 219 | + |
| 220 | +# 定义根路由 |
| 221 | +@app.get("/") |
| 222 | +# 定义根路由处理函数,返回一个包含"Hello"和"World"的字典 |
| 223 | +def read_root(): |
| 224 | + return {"Hello": "World"} |
| 225 | + |
| 226 | + |
| 227 | +# 定义聊天路由 |
| 228 | +@app.post("/chat") |
| 229 | +# 定义聊天路由处理函数,接收一个字符串查询并调用Master类的run方法进行处理 |
| 230 | +def chat(query: str): |
| 231 | + master = Master() # 初始化Master对象 |
| 232 | + return master.run(query) |
| 233 | + |
| 234 | + |
| 235 | +# 定义添加PDF路由 |
| 236 | +@app.post("/add_pdfs") |
| 237 | +# 定义添加PDF路由处理函数,返回一个包含"response"键和"PDFs added!"值的字典 |
| 238 | +def add_pdfs(): |
| 239 | + return {"response": "PDFs added!"} |
| 240 | + |
| 241 | + |
| 242 | +# 定义添加文本路由 |
| 243 | +@app.post("add_texts") |
| 244 | +# 定义添加文本路由处理函数,返回一个包含"response"键和"Texts added!"值的字典 |
| 245 | +def add_texts(): |
| 246 | + return {"response": "Texts added!"} |
| 247 | + |
| 248 | + |
| 249 | +# 定义WebSocket路由 |
| 250 | +@app.websocket("/ws") |
| 251 | +# 定义WebSocket路由处理函数,接收一个WebSocket连接并启动一个无限循环 |
| 252 | +async def websocket_endpoint(websocket: WebSocket): |
| 253 | + await websocket.accept() |
| 254 | + try: |
| 255 | + while True: |
| 256 | + data = await websocket.receive_text() |
| 257 | + await websocket.send_text(f"Message text was: {data}") |
| 258 | + except WebSocketDisconnect: |
| 259 | + print("Connection closed") |
| 260 | + await websocket.close() |
| 261 | + |
| 262 | + |
| 263 | +# 如果主程序为 __main__,则启动服务器 |
| 264 | +if __name__ == "__main__": |
| 265 | + import uvicorn |
| 266 | + |
| 267 | + uvicorn.run(app, host="localhost", port=8090) |
| 268 | +``` |
| 269 | + |
| 270 | +fastapi 请求: |
| 271 | + |
| 272 | + |
| 273 | + |
| 274 | +postman 请求: |
| 275 | + |
| 276 | + |
| 277 | + |
| 278 | +PyCharm 命令行记录: |
| 279 | + |
| 280 | + |
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