///

### Lifespan fonksiyonu { #lifespan-function }

Dikkat edilmesi gereken ilk şey, `yield` içeren async bir fonksiyon tanımlıyor olmamız. Bu, `yield` kullanan Dependencies’e oldukça benzer.

{* ../../docs_src/events/tutorial003_py310.py hl[14:19] *}

Fonksiyonun `yield`’den önceki kısmı, uygulama başlamadan **önce** çalışır.

`yield`’den sonraki kısım ise, uygulama işini bitirdikten **sonra** çalışır.

            if self.open:
                yield item
            else:
                raise ValueError("Session closed")


@contextmanager
def acquire_session() -> Generator[Session, None, None]:
    session = Session()
    try:
        yield session
    finally:
        session.open = False


def dep_session() -> Any:
    with acquire_session() as s:
        yield s


def broken_dep_session() -> Any:

from typing import Annotated, Literal

from fastapi import FastAPI, Query
from pydantic import BaseModel, Field

app = FastAPI()


class FilterParams(BaseModel):
    model_config = {"extra": "forbid"}

    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: list[str] = []


@app.get("/items/")

                    "body",
                    "item",
                ],
                "msg": "Field required",
                "type": "missing",
            },
            {
                "input": None,
                "loc": [
                    "body",
                    "user",
                ],
                "msg": "Field required",
                "type": "missing",
            },
            {

     */
    public String sort;

    /**
     * The language setting for error page display.
     */
    public String lang;

    /**
     * Additional search fields for error page display.
     */
    public Map<String, String[]> fields = new HashMap<>();

    /**
     * Default constructor for ThumbnailForm.
     */
    public ThumbnailForm() {
        // Default constructor
    }

    private Object getFieldValue(Object obj, String fieldName) {
        try {
            Field field = getField(obj.getClass(), fieldName);
            field.setAccessible(true);
            return field.get(obj);
        } catch (Exception e) {
            throw new RuntimeException("Failed to get field value: " + fieldName, e);
        }
    }

async def stream_items() -> AsyncIterable[Item]:
    for item in items:
        yield item


@app.get("/items/stream-no-async")
def stream_items_no_async() -> Iterable[Item]:
    for item in items:
        yield item


@app.get("/items/stream-no-annotation")
async def stream_items_no_annotation():
    for item in items:
        yield item


@app.get("/items/stream-no-async-no-annotation")

### Функція тривалості життя { #lifespan-function }

Перше, на що слід звернути увагу: ми визначаємо асинхронну функцію з `yield`. Це дуже схоже на залежності з `yield`.

{* ../../docs_src/events/tutorial003_py310.py hl[14:19] *}

Перша частина функції до `yield` буде виконана перед запуском застосунку.

А частина після `yield` буде виконана після завершення роботи застосунку.

### Асинхронний менеджер контексту { #async-context-manager }

// formatMetaV1 should be inherited by backend format structs. Please look at format-fs.go
// and format-xl.go for details.

// Ideally we will never have a situation where we will have to change the
// fields of this struct and deal with related migration.
type formatMetaV1 struct {
	// Version of the format config.
	Version string `json:"version"`
	// Format indicates the backend format type, supports two values 'xl' and 'fs'.

from typing import Literal

from fastapi import FastAPI, Query
from pydantic import BaseModel, Field

app = FastAPI()


class FilterParams(BaseModel):
    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: list[str] = []


@app.get("/items/")
async def read_items(filter_query: FilterParams = Query()):