//// tab | Python 3.9+

```Python hl_lines="1"
async def needy_dependency(fresh_value: Annotated[str, Depends(get_value, use_cache=False)]):
    return {"fresh_value": fresh_value}
```

////

//// tab | Python 3.9+ non-Annotated

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="1"

from typing import Annotated, Union

from fastapi import FastAPI, HTTPException, Security
from fastapi.security import (
    OAuth2PasswordBearer,
    SecurityScopes,
)
from fastapi.testclient import TestClient

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")


def process_auth(
    credentials: Annotated[Union[str, None], Security(oauth2_scheme)],
    security_scopes: SecurityScopes,
):

import json
from typing import Annotated

from fastapi import APIRouter, Depends, FastAPI, WebSocket
from fastapi.testclient import TestClient


def dependency_list() -> list[str]:
    return []


DepList = Annotated[list[str], Depends(dependency_list)]


def create_dependency(name: str):
    def fun(deps: DepList):
        deps.append(name)

    return Depends(fun)

////

//// tab | Python 3.10+ 没Annotated

/// tip

尽可能选择使用 `Annotated` 的版本。

///

{* ../../docs_src/background_tasks/tutorial002_py310.py hl[11, 13, 20, 23] *}

////

//// tab | Python 3.8+ 没Annotated

/// tip

尽可能选择使用 `Annotated` 的版本。

///

{* ../../docs_src/background_tasks/tutorial002.py hl[13, 15, 22, 25] *}

////

from datetime import datetime
from typing import Annotated

from fastapi import FastAPI, Security
from fastapi.security import HTTPBearer
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

bearer_scheme = HTTPBearer()


class Subscription(BaseModel):
    username: str
    monthly_fee: float
    start_date: datetime


@app.webhooks.post("new-subscription")
def new_subscription(

from typing import Annotated

from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select


class HeroBase(SQLModel):
    name: str = Field(index=True)
    age: int | None = Field(default=None, index=True)


class Hero(HeroBase, table=True):
    id: int | None = Field(default=None, primary_key=True)
    secret_name: str


class HeroPublic(HeroBase):
    id: int

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[list[str] | None, Query()] = None):
    query_items = {"q": q}

from typing import Annotated

from fastapi import Depends, FastAPI
from fastapi.security import OAuth2PasswordBearer

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")


@app.get("/items/")
async def read_items(token: Annotated[str, Depends(oauth2_scheme)]):

from typing import Annotated

from fastapi import Depends, FastAPI

app = FastAPI()


def get_username():
    try:
        yield "Rick"
    finally:
        print("Cleanup up before response is sent")


@app.get("/users/me")
def get_user_me(username: Annotated[str, Depends(get_username, scope="function")]):

```

////

//// tab | Python 3.10+ non-Annotated

/// tip | 提示

Prefer to use the `Annotated` version if possible.

///

```Python
{!> ../../docs_src/app_testing/app_b_py310/main.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip | 提示

Prefer to use the `Annotated` version if possible.

///

```Python