错误处理

错误处理

向客户端返回HTTP错误响应，可以导入HTTPException，HTTPException包含了与API有关数据的常规python异常。

1. 只能通过raise捕获
2. 触发异常，后续的代码不会再执行
3. HTTPException的detail 参数可传递任意能转换为JSON的值

from fastapi import FastAPI, HTTPException
import uvicorn
app = FastAPI()
items = {"zaygee": "zaygee是个大帅哥"}
@app.get("/items")
async def read_item(item_id: str):
    if item_id not in items:
        raise HTTPException(status_code=404, detail={"msg": "not found"})
    return {"item": items[item_id]}
if __name__ == "__main__":
    uvicorn.run(
        app="error_handler:app",
        host="127.0.0.1",
        port=8080,
        reload=True,
        debug=True,
        log_level="debug",
        access_log=True,
        use_colors=True
    )

自定义异常处理器

通过@app.exception_handler() 添加自定义异常控制器

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
import uvicorn
import pdb
app = FastAPI()
class UnicornException(Exception):
    def __init__(self, name: str):
        self.name = name
# pdb.set_trace()
@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    """
    unicorn_exception_handler在服务启动时初始化，fastapi会全局捕获该异常
    """
    return JSONResponse(
        status_code=518,
        content={"message": f"{exc.name} 是自定义异常的名称"}
    )
@app.get("/unicorn/{name}")
async def read_unicorn(name: str):
    if name == "zaygee":
        # pdb.set_trace()
        raise UnicornException(name=name)    # 异常会被unicorn_exception_handler处理
    return {"unicorn_name": name}
if __name__ == "__main__":
    uvicorn.run(
        app="error_handler:app",
        host="127.0.0.1",
        port=8080,
        reload=True,
        debug=True,
        log_level="debug",
        access_log=True,
        use_colors=True
    )