作用

需要在应用程序启动之前或者关闭时进行，例如数据库迁移，定时任务·····

实际代码

main.py

import uvicorn

from app import create_app

app = create_app()

if __name__ == '__main__':
    uvicorn.run(
        app='main:app',
        host='0.0.0.0',
        port=8000,
        reload=True
    )

#!/usr/bin/python
# -*- coding: utf-8 -*-
# @time    : 2023/2/3 11:28
# @author  : pugongying
# @description : 初始化项目

from fastapi import FastAPI

from app.xxx import task_init
from app.config import log_init
from app.middleware import middleware_init
from app.plan import plan
from app.routers import router_init


async def start_event():
    task_init()
    plan.run_plan()
    print('系统启动')


async def shutdown_event():
    print('系统关闭')


def create_app():
    app = FastAPI(title="xxx服务",
                  description="xxx服务接口文档",
                  version="1.0.0",
                  on_startup=[start_event],
                  on_shutdown=[shutdown_event]
                  )

    # 初始化日志
    log_init()

    # 初始化路由
    router_init(app)

    # 初始化中间件
    middleware_init(app)

    # 建表
    # db_init(app)

    return app