### Is concurrency better than parallelism?

Nope! That's not the moral of the story.

Concurrency is different than parallelism. And it is better on **specific** scenarios that involve a lot of waiting. Because of that, it generally is a lot better than parallelism for web application development. But not for everything.

```json
{"message": "Hello World"}
```

...this response will return:

```json
{
  "message": "Hello World"
}
```

Of course, you will probably find much better ways to take advantage of this than formatting JSON. 😉

## Default response class

When creating a **FastAPI** class instance or an `APIRouter` you can specify which response class to use by default.

...and adapt it with your database data and credentials (equivalently for MySQL, MariaDB or any other).

!!! tip

    This is the main line that you would have to modify if you wanted to use a different database.

### Create the SQLAlchemy `engine`

The first step is to create a SQLAlchemy "engine".

We will later use this `engine` in other places.

```Python hl_lines="8-10"

### Test edildi

* 100% <abbr title="Kodun ne kadarının test edildiği">test coverage</abbr>.
* 100% <abbr title="Python type annotations, with this your editor and external tools can give you better support">typeları belirtilmiş</abbr> codebase.
* FastAPI ile yapılan bir çok proje insanlar tarafından kullanılıyor.

## Starlette özellikleri

* `float`
* `bool`
* `bytes`

```Python hl_lines="1"
{!../../../docs_src/python_types/tutorial005.py!}
```

### Tipos genéricos com parâmetros de tipo

Existem algumas estruturas de dados que podem conter outros valores, como `dict`, `list`, `set` e `tuple`. E os valores internos também podem ter seu próprio tipo.

Para declarar esses tipos e os tipos internos, você pode usar o módulo Python padrão `typing`.

And we know that editors can't provide a lot of support (like completion) for `dict`s, because they can't know their keys and value types.

We can do better...

## What makes a dependency

Up to now you have seen dependencies declared as functions.

But that's not the only way to declare dependencies (although it would probably be the more common).

!!! warning
    There's a high chance that you **don't** need this base image or any other similar one, and would be better off by building the image from scratch as [described above in: Build a Docker Image for FastAPI](#build-a-docker-image-for-fastapi).

!!! note
    FastAPI will know that the value of `q` is not required because of the default value `= None`.

    The `Union` in `Union[str, None]` is not used by FastAPI, but will allow your editor to give you better support and detect errors.

## Without Pydantic

  ```
  다른 일반적인 대화에서만 채팅을 사용하십시오.
  ```

  기존 [지터 채팅](https://gitter.im/tiangolo/fastapi) 이 있지만 채널과 고급기능이 없어서 대화를 하기가 조금 어렵기 때문에 지금은 디스코드가 권장되는 시스템입니다.

  ### 질문을 위해 채팅을 사용하지 마십시오

  채팅은 더 많은 "자유로운 대화"를 허용하기 때문에, 너무 일반적인 질문이나 대답하기 어려운 질문을 쉽게 질문을 할 수 있으므로, 답변을 받지 못할 수 있습니다.

You could use these tools and ideas if you are setting up **your own deployment system** while taking care of the other deployment concepts yourself.