与使用 Pydantic 声明请求体相同，并且可在任何位置使用：

{* ../../docs_src/security/tutorial002_an_py310.py hl[5,12:6] *}

## 创建 `get_current_user` 依赖项 { #create-a-get-current-user-dependency }

创建 `get_current_user` 依赖项。

还记得依赖项支持子依赖项吗？

`get_current_user` 使用 `oauth2_scheme` 作为依赖项。

与之前直接在路径操作中的做法相同，新的 `get_current_user` 依赖项从子依赖项 `oauth2_scheme` 中接收 `str` 类型的 `token`：

{* ../../docs_src/security/tutorial002_an_py310.py hl[25] *}

    ):
        call_counts["get_current_user"] += 1
        return {
            "user": f"user_{call_counts['get_current_user']}",
            "scopes": security_scopes.scopes,
            "db_session": db_session,
        }

    def get_user_me(
        current_user: Annotated[dict, Security(get_current_user, scopes=["me"])],
    ):
        call_counts["get_user_me"] += 1
        return {

app = FastAPI()

api_key = APIKeyCookie(name="key")


class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user


@app.get("/users/me")
def read_current_user(current_user: User = Depends(get_current_user)):
    return current_user


def test_security_api_key():
    client = TestClient(app, cookies={"key": "secret"})

class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user


@app.get("/users/me")
def read_current_user(current_user: User = Depends(get_current_user)):
    return current_user


def test_security_api_key():
    client = TestClient(app, cookies={"key": "secret"})

app = FastAPI()

api_key = APIKeyQuery(name="key")


class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user


@app.get("/users/me")
def read_current_user(current_user: User = Depends(get_current_user)):
    return current_user


client = TestClient(app)


def test_security_api_key():

    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:

class User(BaseModel):
    username: str


def get_current_user(oauth_header: str | None = Security(api_key)):
    if oauth_header is None:
        return None
    user = User(username=oauth_header)
    return user


@app.get("/users/me")
def read_current_user(current_user: User | None = Depends(get_current_user)):
    if current_user is None:
        return {"msg": "Create an account first"}

## 相依性樹與 scopes { #dependency-tree-and-scopes }

我們再回顧一次這個相依性樹與 scopes。

由於 `get_current_active_user` 相依於 `get_current_user`，因此在 `get_current_active_user` 宣告的 `"me"` 這個 scope 會包含在傳給 `get_current_user` 的 `security_scopes.scopes` 的必須 scopes 清單中。

路徑操作本身也宣告了 `"items"` 這個 scope，因此它也會包含在傳給 `get_current_user` 的 `security_scopes.scopes` 中。

以下是相依性與 scopes 的階層關係：

- 路徑操作 `read_own_items` 具有：
  - 需要的 scopes `["items"]`，並有相依性：

    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:

{* ../../docs_src/security/tutorial002_an_py310.py hl[5,12:6] *}

## Create a `get_current_user` dependency { #create-a-get-current-user-dependency }

Let's create a dependency `get_current_user`.

Remember that dependencies can have sub-dependencies?

`get_current_user` will have a dependency with the same `oauth2_scheme` we created before.