### Функция lifespan { #lifespan-function }

Первое, на что стоит обратить внимание, — мы определяем асинхронную функцию с `yield`. Это очень похоже на Зависимости с `yield`.

{* ../../docs_src/events/tutorial003_py39.py hl[14:19] *}

Первая часть функции, до `yield`, будет выполнена до запуска приложения.

А часть после `yield` будет выполнена после завершения работы приложения.

### Асинхронный менеджер контекста { #async-context-manager }

Lo primero que hay que notar es que estamos definiendo una función asíncrona con `yield`. Esto es muy similar a las Dependencias con `yield`.

{* ../../docs_src/events/tutorial003_py39.py hl[14:19] *}

La primera parte de la función, antes del `yield`, será ejecutada **antes** de que la aplicación comience.

Y la parte después del `yield` será ejecutada **después** de que la aplicación haya terminado.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/cookie_param_models/tutorial002_an_py310.py hl[10] *}

If a client tries to send some **extra cookies**, they will receive an **error** response.

          </association>
        </field>
      </fields>
    </class>
    <class>
      <name>Profile</name>
      <version>1.0.0</version>
      <description><![CDATA[
        Modifications to the build process which is keyed on some
        sort of environmental parameter.
      ]]></description>
      <fields>
        <field>
          <name>id</name>
          <required>true</required>

			mapValue[column] = nil
		}
	}
}

func (db *DB) scanIntoStruct(rows Rows, reflectValue reflect.Value, values []interface{}, fields []*schema.Field, joinFields [][]*schema.Field) {
	for idx, field := range fields {
		if field != nil {
			values[idx] = field.NewValuePool.Get()
		} else if len(fields) == 1 {
			if reflectValue.CanAddr() {
				values[idx] = reflectValue.Addr().Interface()
			} else {

	checkUserSchema(t, user)
}

func checkUserSchema(t *testing.T, user *schema.Schema) {
	// check schema
	checkSchema(t, user, &schema.Schema{Name: "User", Table: "users"}, []string{"ID"})

	// check fields
	fields := []schema.Field{

/**
 * Annotation used to mark fields that represent configuration properties.
 * This annotation provides metadata about how the configuration property
 * should be handled, including its source, type, default value, and whether it's read-only.
 *
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.FIELD)
public @interface Config {

    /**

| `terms_of_service` | `str` | A URL to the Terms of Service for the API. If provided, this has to be a URL. |

		return nil
	}
	val := int(n.NoncurrentDays)
	switch {
	case val == 0 && n.NewerNoncurrentVersions == 0:
		// both fields can't be zero
		return errXMLNotWellFormed

	case val < 0, n.NewerNoncurrentVersions < 0:
		// negative values are not supported
		return errXMLNotWellFormed
	}
	return nil
}

// NoncurrentVersionTransition - an action for lifecycle configuration rule.
type NoncurrentVersionTransition struct {

새로운 버전을 시작해야 하거나, 그냥 실행을 멈추고 싶을 수도 있습니다. 🤷

///

### Lifespan 함수

먼저 주목할 점은, `yield`를 사용하여 비동기 함수(async function)를 정의하고 있다는 것입니다. 이는 `yield`를 사용한 의존성과 매우 유사합니다.

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

함수의 첫 번째 부분, 즉 `yield` 이전의 코드는 애플리케이션이 시작되기 **전에** 실행됩니다.

그리고 `yield` 이후의 부분은 애플리케이션이 완료된 후 **나중에** 실행됩니다.

### 비동기 컨텍스트 매니저

함수를 확인해보면, `@asynccontextmanager`로 장식되어 있습니다.