sending the `client_id` and `client_secret` (if any) using HTTP Basic
                auth.
                """
            ),
        ] = None,
    ):
        self.grant_type = grant_type
        self.username = username
        self.password = password
        self.scopes = scope.split()
        self.client_id = client_id
        self.client_secret = client_secret

                    "required": ["username", "password"],
                    "type": "object",
                    "properties": {
                        "grant_type": IsDict(
                            {
                                "title": "Grant Type",
                                "anyOf": [
                                    {"pattern": "password", "type": "string"},

                {
                    "loc": ["body", "grant_type"],
                    "msg": "field required",
                    "type": "value_error.missing",
                }
            ]
        }
    )


def test_strict_login_incorrect_grant_type():
    response = client.post(
        "/login",
        data={"username": "johndoe", "password": "secret", "grant_type": "incorrect"},
    )

                    "required": ["username", "password"],
                    "type": "object",
                    "properties": {
                        "grant_type": IsDict(
                            {
                                "title": "Grant Type",
                                "anyOf": [
                                    {"pattern": "password", "type": "string"},

{!../../../docs_src/security/tutorial003.py!}
```

`OAuth2PasswordRequestForm` 是用以下几项内容声明表单请求体的类依赖项：

* `username`
* `password`
* 可选的 `scope` 字段，由多个空格分隔的字符串组成的长字符串
* 可选的 `grant_type`

!!! tip "提示"

    实际上，OAuth2 规范*要求* `grant_type` 字段使用固定值 `password`，但 `OAuth2PasswordRequestForm` 没有作强制约束。

    如需强制使用固定值 `password`，则不要用 `OAuth2PasswordRequestForm`，而是用 `OAuth2PasswordRequestFormStrict`。

* 可选的 `client_id`（本例未使用）

    ```

`OAuth2PasswordRequestForm` 🎓 🔗 👈 📣 📨 💪 ⏮️:

*  `username`.
*  `password`.
* 📦 `scope` 🏑 🦏 🎻, ✍ 🎻 🎏 🚀.
* 📦 `grant_type`.

!!! tip
    Oauth2️⃣ 🔌 🤙 *🚚* 🏑 `grant_type` ⏮️ 🔧 💲 `password`, ✋️ `OAuth2PasswordRequestForm` 🚫 🛠️ ⚫️.

    🚥 👆 💪 🛠️ ⚫️, ⚙️ `OAuth2PasswordRequestFormStrict` ↩️ `OAuth2PasswordRequestForm`.

* 📦 `client_id` (👥 🚫 💪 ⚫️ 👆 🖼).

                    "required": ["username", "password"],
                    "type": "object",
                    "properties": {
                        "grant_type": IsDict(
                            {
                                "title": "Grant Type",
                                "anyOf": [
                                    {"pattern": "password", "type": "string"},

                    "required": ["username", "password"],
                    "type": "object",
                    "properties": {
                        "grant_type": IsDict(
                            {
                                "title": "Grant Type",
                                "anyOf": [
                                    {"pattern": "password", "type": "string"},

                {
                    "loc": ["body", "grant_type"],
                    "msg": "field required",
                    "type": "value_error.missing",
                }
            ]
        }
    )


def test_strict_login_incorrect_grant_type():
    response = client.post(
        "/login",
        data={"username": "johndoe", "password": "secret", "grant_type": "incorrect"},
    )

                {
                    "loc": ["body", "grant_type"],
                    "msg": "field required",
                    "type": "value_error.missing",
                }
            ]
        }
    )


def test_strict_login_incorrect_grant_type():
    response = client.post(
        "/login",
        data={"username": "johndoe", "password": "secret", "grant_type": "incorrect"},
    )