app = FastAPI()


def fake_hash_password(password: str):
    return "fakehashed" + password


oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


def get_user(db, username: str):

    with pytest.raises(RuntimeError, match=multipart_incorrect_install_error):
        app = FastAPI()

        @app.post("/")
        async def root(username: str = Form(), password: str = Form()):
            return username  # pragma: nocover


def test_incorrect_multipart_installed_form_file(monkeypatch):
    monkeypatch.setattr("python_multipart.__version__", "0.0.12")

     */
    public Tokenizer(final String str) {
        this(str, defaultCtype);
    }

    /**
     * {@link Tokenizer}を作成します。
     *
     * @param str
     *            文字列。{@literal null}であってはいけません
     * @param ctype
     *            文字のタイプの配列。{@literal null}や空配列であってはいけません
     */
    public Tokenizer(final String str, final byte[] ctype) {
        assertArgumentNotNull("str", str);

}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str

{!../../docs_src/python_types/tutorial009.py!}
```

Использование `Optional[str]` вместо просто `str` позволит редактору помочь вам в обнаружении ошибок, в которых вы могли бы предположить, что значение всегда является `str`, хотя на самом деле это может быть и `None`.

#### Generic-типы

Эти типы принимают параметры в квадратных скобках:

* `List`
* `Tuple`
* `Set`
* `Dict`
* `Optional`
* ...и др.

class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str

        final Date date = toDate(str, locale);
        if (date != null) {
            return new java.sql.Date(date.getTime());
        }
        final java.sql.Date sqlDate = toSqlDateJdbcEscape(str);
        if (sqlDate != null) {
            return sqlDate;
        }
        throw new ParseRuntimeException(str);
    }

    /**
     * 文字列を{@link Date}に変換します。
     *
     * @param str
     *            文字列

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: List[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Image(BaseModel):
    url: str
    name: str


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None
    tags: set[str] = set()
    image: Union[Image, None] = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):

app = FastAPI()


def query_extractor(q: str | None = None):
    return q


def query_or_cookie_extractor(
    q: str = Depends(query_extractor), last_query: str | None = Cookie(default=None)
):
    if not q:
        return last_query
    return q


@app.get("/items/")
async def read_query(query_or_default: str = Depends(query_or_cookie_extractor)):