python fastapi接口鉴权方法

FastAPI支持基于Bearer Token的鉴权方法，可以使用FastAPI自带的Depends函数结合PyJWT库实现。

以下是一个示例代码：

from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
import jwt

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")

def verify_token(token: str):
    try:
        payload = jwt.decode(token, "secret_key", algorithms=["HS256"])
        username = payload.get("sub")
        if username is None:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Invalid authentication credentials",
                headers={"WWW-Authenticate": "Bearer"},
            )
    except jwt.exceptions.DecodeError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid authentication credentials",
            headers={"WWW-Authenticate": "Bearer"},
        )

def get_current_user(token: str = Depends(oauth2_scheme)):
    verify_token(token)
    return token

@app.get("/protected")
async def protected_route(token: str = Depends(oauth2_scheme)):
    return {"token": token}

在这个示例中，verify_token函数用于验证JWT Token的有效性，get_current_user函数用于获取当前用户信息，protected_route函数需要鉴权才能访问。在访问protected_route时，会自动调用get_current_user函数进行鉴权。如果鉴权失败，会返回401 Unauthorized错误。