@needs_py39
def test_post_body_form(client: TestClient):
    response = client.post("/login/", data={"username": "Foo", "password": "secret"})
    assert response.status_code == 200
    assert response.json() == {"username": "Foo"}


@needs_py39
def test_post_body_form_no_password(client: TestClient):
    response = client.post("/login/", data={"username": "Foo"})
    assert response.status_code == 422
    assert response.json() == IsDict(

Um dies zu lösen, konvertieren wir zunächst den `username` und das `password` in UTF-8-codierte `bytes`.

Dann können wir `secrets.compare_digest()` verwenden, um sicherzustellen, dass `credentials.username` `"stanleyjobson"` und `credentials.password` `"swordfish"` ist.

=== "Python 3.9+"

    ```Python hl_lines="1  12-24"

	currTime := UTCNow()

	var (
		username = cred.AccessKey
		claims   = cred.Claims
		groups   = cred.Groups
	)

	if cred.IsTemp() || cred.IsServiceAccount() {
		// For derived credentials, check the parent user's permissions.
		username = cred.ParentUser
	}

	principalType := "Anonymous"
	if username != "" {
		principalType = "User"
		if len(claims) > 0 {

def test_post_body_form(client: TestClient):
    response = client.post("/login/", data={"username": "Foo", "password": "secret"})
    assert response.status_code == 200
    assert response.json() == {"username": "Foo"}


def test_post_body_form_no_password(client: TestClient):
    response = client.post("/login/", data={"username": "Foo"})
    assert response.status_code == 422
    assert response.json() == IsDict(
        {

def test_post_body_form(client: TestClient):
    response = client.post("/login/", data={"username": "Foo", "password": "secret"})
    assert response.status_code == 200
    assert response.json() == {"username": "Foo"}


def test_post_body_form_no_password(client: TestClient):
    response = client.post("/login/", data={"username": "Foo"})
    assert response.status_code == 422
    assert response.json() == IsDict(
        {

Então, vamos rever de um ponto de vista simplificado:

* O usuário digita o `username` e a `senha` no frontend e aperta `Enter`.
* O frontend (rodando no browser do usuário) manda o `username` e a `senha` para uma URL específica na sua API (declarada com `tokenUrl="token"`).
* A API checa aquele `username` e `senha`, e responde com um "token" (nós não implementamos nada disso ainda).

        }
    },
    auto_error=False,
)


class User(BaseModel):
    username: str


def get_current_user(oauth_header: Optional[str] = Security(reusable_oauth2)):
    if oauth_header is None:
        return None
    user = User(username=oauth_header)
    return user


@app.post("/login")
def login(form_data: OAuth2PasswordRequestFormStrict = Depends()):

```Python
UserInDB(**user_dict)
```

就会生成如下结果：

```Python
UserInDB(
    username="john",
    password="secret",
    email="******@****.***",
    full_name=None,
)
```

或更精准，直接把可能会用到的内容与 `user_dict` 一起使用：

```Python
UserInDB(
    username = user_dict["username"],
    password = user_dict["password"],
    email = user_dict["email"],
    full_name = user_dict["full_name"],

UserInDB(**user_dict)
```

dann ist das ungefähr äquivalent zu:

```Python
UserInDB(
    username="john",
    password="secret",
    email="******@****.***",
    full_name=None,
)
```

Oder, präziser, `user_dict` wird direkt verwendet, welche Werte es auch immer haben mag:

```Python
UserInDB(
    username = user_dict["username"],
    password = user_dict["password"],
    email = user_dict["email"],

                """
            ),
        ] = None,
        username: Annotated[
            str,
            Form(),
            Doc(
                """
                `username` string. The OAuth2 spec requires the exact field name
                `username`.
                """
            ),
        ],
        password: Annotated[
            str,