5、Optional和Union

from fastapi import APIRouter
from typing import Union, Optional

app02 = APIRouter()


@app02.get("/jobs/{kd}")
async def get_jobs(kd, xl: Union[str, None] = None, gj: Optional[str] = None):  # Optional[str], 相当于Union[str, None]
    return {
        "kd": kd,
        "xl": xl,
        "gj": gj
    }