Тогда **FastAPI** будет вызывать это переопределение вместо исходной зависимости.

{* ../../docs_src/dependency_testing/tutorial001_an_py310.py hl[26:27,30] *}

/// tip | Совет

Вы можете задать переопределение для зависимости, используемой в любом месте вашего приложения **FastAPI**.

解码并校验接收到的令牌，然后，返回当前用户。

如果令牌无效，则直接返回 HTTP 错误。

{* ../../docs_src/security/tutorial004_an_py310.py hl[4,7,13:15,29:31,79:87] *}

## 更新 `/token` *路径操作*

用令牌过期时间创建 `timedelta` 对象。

创建并返回真正的 JWT 访问令牌。

{* ../../docs_src/security/tutorial004_an_py310.py hl[118:133] *}

### JWT `sub` 的技术细节

JWT 规范还包括 `sub` 键，值是令牌的主题。

该键是可选的，但要把用户标识放在这个键里，所以本例使用了该键。

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002_py39"),
        pytest.param("tutorial002_py310", marks=[needs_py310]),
        pytest.param("tutorial002_an_py39"),
        pytest.param("tutorial002_an_py310", marks=[needs_py310]),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.header_param_models.{request.param}")

    client = TestClient(mod.app)

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py39"),
        pytest.param("tutorial001_py310", marks=needs_py310),
        pytest.param("tutorial001_an_py39"),
        pytest.param("tutorial001_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.query_param_models.{request.param}")

    client = TestClient(mod.app)

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002_py39"),
        pytest.param("tutorial002_py310", marks=[needs_py310]),
        pytest.param("tutorial002_an_py39"),
        pytest.param("tutorial002_an_py310", marks=[needs_py310]),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.query_param_models.{request.param}")

    client = TestClient(mod.app)

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002_py39"),
        pytest.param("tutorial002_py310", marks=needs_py310),
        pytest.param("tutorial002_an_py39"),
        pytest.param("tutorial002_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.security.{request.param}")
    client = TestClient(mod.app)
    return client

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py39"),
        pytest.param("tutorial001_py310", marks=needs_py310),
        pytest.param("tutorial001_an_py39"),
        pytest.param("tutorial001_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.header_param_models.{request.param}")

    client = TestClient(mod.app)

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[3] *}

### Die Abhängigkeit im <abbr title="Das Abhängige, der Verwender der Abhängigkeit">„Dependant“</abbr> deklarieren { #declare-the-dependency-in-the-dependant }

So wie auch `Body`, `Query`, usw., verwenden Sie `Depends` mit den Parametern Ihrer *Pfadoperation-Funktion*:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[13,18] *}

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial003_py39"),
        pytest.param("tutorial003_py310", marks=needs_py310),
        pytest.param("tutorial003_an_py39"),
        pytest.param("tutorial003_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.security.{request.param}")

    client = TestClient(mod.app)
    return client

{* ../../docs_src/security/tutorial004_an_py310.py hl[90:107] *}

## Atualize a *operação de rota* `/token` { #update-the-token-path-operation }

Crie um `timedelta` com o tempo de expiração do token.

Crie um token de acesso JWT real e o retorne.

{* ../../docs_src/security/tutorial004_an_py310.py hl[118:133] *}