В Python «**вызываемый**» — это всё, что Python может «вызвать», как функцию.

Так, если у вас есть объект `something` (который может и _не_ быть функцией) и вы можете «вызвать» его (выполнить) так:

```Python
something()
```

или

```Python
something(some_argument, some_keyword_argument="foo")
```

в таком случае он является «вызываемым».

            "age": "70",
            "tags": ["plumbus", "citadel"],
            "with": "something",
        },
    )
    assert response.status_code == 200, response.text
    assert response.json() == {
        "username": "Rick",
        "lastname": "Sanchez",
        "age": 70,
        "tags": ["plumbus", "citadel"],
        "with": "something",
    }


def test_defaults():

If you check, the function is decorated with an `@asynccontextmanager`.

That converts the function into something called an "**async context manager**".

{* ../../docs_src/events/tutorial003_py39.py hl[1,13] *}

A **context manager** in Python is something that you can use in a `with` statement, for example, `open()` can be used as a context manager:

```Python
with open("file.txt") as file:

Un "**callable**" en Python es cualquier cosa que Python pueda "llamar" como una función.

Entonces, si tienes un objeto `something` (que podría _no_ ser una función) y puedes "llamarlo" (ejecutarlo) como:

```Python
something()
```

o

```Python
something(some_argument, some_keyword_argument="foo")
```

entonces es un "callable".

## Clases como dependencias { #classes-as-dependencies_1 }

/// info | `@decorator` Info

That `@something` syntax in Python is called a "decorator".

You put it on top of a function. Like a pretty decorative hat (I guess that's where the term came from).

A "decorator" takes the function below and does something with it.

到目前为止，您看到的依赖项都被声明为函数。

但这并不是声明依赖项的唯一方法(尽管它可能是更常见的方法)。

关键因素是依赖项应该是 "可调用对象"。

Python 中的 "**可调用对象**" 是指任何 Python 可以像函数一样 "调用" 的对象。

所以，如果你有一个对象 `something` (可能*不是*一个函数)，你可以 "调用" 它(执行它)，就像：

```Python
something()
```

或者

```Python
something(some_argument, some_keyword_argument="foo")
```

这就是 "可调用对象"。

## 类作为依赖项

您可能会注意到，要创建一个 Python 类的实例，您可以使用相同的语法。

举个例子:

```Python

# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.
* Then it passes the **request** to be processed by the rest of the application (by some *path operation*).
* It then takes the **response** generated by the application (by some *path operation*).
* It can do something to that **response** or run any needed code.
* Then it returns the **response**.

아마도 더 일반적이기는 하겠지만 의존성을 선언하는 유일한 방법은 아닙니다.

핵심 요소는 의존성이 "호출 가능"해야 한다는 것입니다

파이썬에서의 "**호출 가능**"은 파이썬이 함수처럼 "호출"할 수 있는 모든 것입니다.

따라서, 만약 당신이 `something`(함수가 아닐 수도 있음) 객체를 가지고 있고,

```Python
something()
```

또는

```Python
something(some_argument, some_keyword_argument="foo")
```

상기와 같은 방식으로 "호출(실행)" 할 수 있다면 "호출 가능"이 됩니다.

## 의존성으로서의 클래스

A "**callable**" in Python is anything that Python can "call" like a function.

So, if you have an object `something` (that might _not_ be a function) and you can "call" it (execute it) like:

```Python
something()
```

or

```Python
something(some_argument, some_keyword_argument="foo")
```

then it is a "callable".

## Classes as dependencies { #classes-as-dependencies_1 }