You can combine normal FastAPI *path operations* with GraphQL on the same application.

/// tip

**GraphQL** solves some very specific use cases.

It has **advantages** and **disadvantages** when compared to common **web APIs**.

Make sure you evaluate if the **benefits** for your use case compensate the **drawbacks**. 🤓

///

## GraphQL Libraries { #graphql-libraries }

```Python
q: Annotated[str, Query()] = "rick"
```

...or in older code bases you will find:

```Python
q: str = Query(default="rick")
```

### Advantages of `Annotated` { #advantages-of-annotated }

**Using `Annotated` is recommended** instead of the default value in function parameters, it is **better** for multiple reasons. 🤓

## Requirements { #requirements }

After testing several alternatives, I decided that I was going to use [**Pydantic**](https://docs.pydantic.dev/) for its advantages.

Then I contributed to it, to make it fully compliant with JSON Schema, to support different ways to define constraint declarations, and to improve editor support (type checks, autocompletion) based on the tests in several editors.

Define a file parameter with a type of `UploadFile`:

{* ../../docs_src/request_files/tutorial001_an_py310.py hl[14] *}

Using `UploadFile` has several advantages over `bytes`:

* You don't have to use `File()` in the default value of the parameter.
* It uses a "spooled" file:

This is just a **quick tutorial / refresher** about Python type hints. It covers only the minimum necessary to use them with **FastAPI**... which is actually very little.

**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

따라서 (가능하면) 다음과 같이 사용합니다:

```Python
q: Annotated[str, Query()] = "rick"
```

...또는 오래된 코드베이스에서는 다음과 같은 코드를 찾게 될 것입니다:

```Python
q: str = Query(default="rick")
```

### `Annotated`의 장점 { #advantages-of-annotated }

함수 매개변수의 기본값 방식 대신 **`Annotated`를 사용하는 것을 권장**합니다. 여러 이유로 **더 좋기** 때문입니다. 🤓

**함수 매개변수**의 **기본값**이 **실제 기본값**이 되므로, 전반적으로 Python에 더 직관적입니다. 😌

Using Linux containers has several advantages including **security**, **replicability**, **simplicity**, and others.

/// tip

In a hurry and already know this stuff? Jump to the [`Dockerfile` below 👇](#build-a-docker-image-for-fastapi).

///

<details>

因此，你应该这样用（推荐）：

```Python
q: Annotated[str, Query()] = "rick"
```

...或者在旧代码库中你会见到：

```Python
q: str = Query(default="rick")
```

### `Annotated` 的优势 { #advantages-of-annotated }

**推荐使用 `Annotated`**，而不是把 `Query` 放在函数参数的默认值里，这样做在多方面都**更好**。🤓

函数参数的**默认值**就是**真正的默认值**，这与 Python 的直觉更一致。😌

そのため、（できれば）次のようにします:

```Python
q: Annotated[str, Query()] = "rick"
```

...または、古いコードベースでは次のようなものが見つかるでしょう:

```Python
q: str = Query(default="rick")
```

### `Annotated` の利点 { #advantages-of-annotated }

関数パラメータのデフォルト値スタイルではなく、**`Annotated` を使うことが推奨** されます。複数の理由で **より良い** からです。 🤓

**関数パラメータ** の **デフォルト値** は **実際のデフォルト値** であり、Python 全般としてより直感的です。 😌

```Python
q: Annotated[str, Query()] = "rick"
```

... ou dans des bases de code plus anciennes, vous trouverez :

```Python
q: str = Query(default="rick")
```

### Avantages de `Annotated` { #advantages-of-annotated }

**L’utilisation de `Annotated` est recommandée** plutôt que la valeur par défaut dans les paramètres de fonction, c’est **mieux** pour plusieurs raisons. 🤓