So, the section with:

{% raw %}

```jinja
<a href="{{ url_for('read_item', id=id) }}">
```

{% endraw %}

...will generate a link to the same URL that would be handled by the *path operation function* `read_item(id=id)`.

For example, with an ID of `42`, this would render:

```html

Здесь переменная `app` будет экземпляром класса `FastAPI`.

Это будет основная точка взаимодействия для создания всего вашего API.

### Шаг 3: создайте *операцию пути (path operation)* { #step-3-create-a-path-operation }

#### Путь (path) { #path }

Здесь «путь» — это последняя часть URL, начиная с первого символа `/`.

Итак, в таком URL:

```
https://example.com/items/foo
```

		return "Unknown"
	}
}

// InsufficientReadQuorum storage cannot satisfy quorum for read operation.
type InsufficientReadQuorum struct {
	Bucket string
	Object string
	Err    error
	Type   RQErrType
}

func (e InsufficientReadQuorum) Error() string {
	return "Storage resources are insufficient for the read operation " + e.Bucket + "/" + e.Object
}

// Unwrap the error.

    return {"name": fake_items_db[item_id]["name"], "item_id": item_id}


@router.put(
    "/{item_id}",
    tags=["custom"],
    responses={403: {"description": "Operation forbidden"}},
)
async def update_item(item_id: str):
    if item_id != "plumbus":
        raise HTTPException(
            status_code=403, detail="You can only update the item: plumbus"
        )

		config.HelpKV{
			Key:         Sleep,
			Description: `maximum sleep duration between objects to slow down heal operation` + defaultHelpPostfix(Sleep),
			Optional:    true,
			Type:        "duration",
		},
		config.HelpKV{
			Key:         IOCount,
			Description: `maximum IO requests allowed between objects to slow down heal operation` + defaultHelpPostfix(IOCount),
			Optional:    true,
			Type:        "int",
		},
		config.HelpKV{

    @Override
    public void setRootLoggerLevel(Level level) {
        LOGGER.warn("setRootLoggerLevel: operation not supported");
    }

    @Override
    public void activate() {
        LOGGER.warn("activate(): operation not supported");
    }

# Body - Campos { #body-fields }

De la misma manera que puedes declarar validaciones adicionales y metadatos en los parámetros de las *path operation function* con `Query`, `Path` y `Body`, puedes declarar validaciones y metadatos dentro de los modelos de Pydantic usando `Field` de Pydantic.

## Importar `Field` { #import-field }

Primero, tienes que importarlo:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}

/// warning | Advertencia

Um einen Artikel zu aktualisieren, können Sie die <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PUT" class="external-link" target="_blank">HTTP `PUT`</a> Operation verwenden.

Then we can use the dependency with:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[23] *}

/// info

Notice that we are only declaring one dependency in the *path operation function*, the `query_or_cookie_extractor`.

But **FastAPI** will know that it has to solve `query_extractor` first, to pass the results of that to `query_or_cookie_extractor` while calling it.

///

```mermaid

///

### Funciones de *path operation* { #path-operation-functions }

Cuando declaras una *path operation function* con `def` normal en lugar de `async def`, se ejecuta en un threadpool externo que luego es esperado, en lugar de ser llamado directamente (ya que bloquearía el servidor).