FastAPI与Redis+Celery实现异步和定时任务详解

FastAPI是一个现代、快速（高性能）的基于Python 3.6+的web框架，用于构建APIs。它使用标准Python类型提示，使你的代码具有强大的类型检查功能，并支持依赖注入、快速开发等特点。
Redis是一个开源的、内存中的数据结构存储系统，可以用作数据库、缓存和消息代理。它支持多种数据结构，如字符串、哈希表、列表、集合等。
Celery是一个分布式任务队列，使用AMQP（高级消息队列协议）作为中间件，允许你在不同的机器或进程上异步执行任务。
一、异步任务
异步任务是指在执行过程中不阻塞主程序的执行，可以同时执行其他任务。FastAPI本身并不直接支持异步操作，但可以通过集成Celery来实现。

1. 安装依赖
   首先，确保已安装FastAPI、Celery和Redis的相关依赖。你可以使用pip进行安装：

   pip install fastapi[all] celery redis

2. 配置Celery
   在项目根目录下创建一个名为celery.py的文件，用于配置Celery。在该文件中，你需要导入Celery并配置Redis作为消息代理：

   from celery import Celery
   app = Celery('tasks', broker='redis://localhost:6379/0')

3. 定义异步任务
   在celery.py文件中，定义一个异步任务。例如，以下是一个简单的异步任务，用于将两个数字相加：

   @app.task
   def add(x, y):
   return x + y

4. 在FastAPI中使用异步任务
   在FastAPI应用程序中，你可以通过调用异步任务来执行它。首先，导入add任务：

   from .celery import add

   然后，在FastAPI路由中调用该任务：
   ```python
   from fastapi import FastAPI, Request
   from fastapi.responses import JSONResponse, PlainTextResponse
   from fastapi.routing import APIRoute, APIRouter, Depends, get, post, put, delete, patch, route, include # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi.responses import RedirectResponse # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi.security import HTTPAuthorizationCredentials, HTTPDigest # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import SecurityScopes # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import HTTPBearer, HTTPScopes # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import HTTPAuthorizationCredentials, HTTPDigest # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import SecurityScopes # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import HTTPBearer, HTTPScopes # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import SecurityScopes # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import HTTPAuthorizationCredentials, HTTPDigest # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import HTTPAuthorizationCredentials, HTTPDigest # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import SecurityScopes # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import HTTPBearer, HTTPScopes # type: ignore[import] # ignore type hint for the routes below. they are strings not functions.
   from fastapi_security import SecurityScopes #