```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"],

        openapi_url=app.openapi_url,
        title=app.title + " - ReDoc",
        redoc_js_url="/static/redoc.standalone.js",
    )


@app.get("/users/{username}")
async def read_user(username: str):

                    "required": IsOneOf(
                        ["username", "email", "full_name", "disabled"],
                        # TODO: remove when deprecating Pydantic v1
                        ["username"],
                    ),
                    "type": "object",
                    "properties": {
                        "username": {"title": "Username", "type": "string"},
                        "email": IsDict(

                    "required": IsOneOf(
                        ["username", "email", "full_name", "disabled"],
                        # TODO: remove when deprecating Pydantic v1
                        ["username"],
                    ),
                    "type": "object",
                    "properties": {
                        "username": {"title": "Username", "type": "string"},
                        "email": IsDict(

@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):
    if item_id not in data:
        raise HTTPException(status_code=404, detail="Item not found")
    item = data[item_id]
    if item["owner"] != username:
        raise OwnerError(username)

                    },
                },
                "ModelB": {
                    "title": "ModelB",
                    "required": ["username"],
                    "type": "object",
                    "properties": {"username": {"title": "Username", "type": "string"}},
                },
                "ValidationError": {
                    "title": "ValidationError",

	opts.Port = 14223
	opts.Username = "testminio"
	opts.Password = "miniotest"
	s := natsserver.RunServer(&opts)
	defer s.Shutdown()

	clientConfig := &NATSArgs{
		Enable: true,
		Address: xnet.Host{
			Name:      "localhost",
			Port:      (xnet.Port(opts.Port)),
			IsPortSet: true,
		},
		Subject:  "test",
		Username: opts.Username,
		Password: opts.Password,
	}

from pydantic import BaseModel, EmailStr

app = FastAPI()


class UserIn(BaseModel):
    username: str
    password: str
    email: EmailStr
    full_name: Union[str, None] = None


class UserOut(BaseModel):
    username: str
    email: EmailStr
    full_name: Union[str, None] = None


class UserInDB(BaseModel):
    username: str
    hashed_password: str
    email: EmailStr
    full_name: Union[str, None] = None

So, let's review it from that simplified point of view:

* The user types the `username` and `password` in the frontend, and hits `Enter`.
* The frontend (running in the user's browser) sends that `username` and `password` to a specific URL in our API (declared with `tokenUrl="token"`).
* The API checks that `username` and `password`, and responds with a "token" (we haven't implemented any of this yet).

                    "type": "object",
                    "title": "HTTPValidationError",
                },
                "Subscription": {
                    "properties": {
                        "username": {"type": "string", "title": "Username"},
                        "monthly_fee": {"type": "number", "title": "Monthly Fee"},
                        "start_date": {
                            "type": "string",