* Path operasyonu parametreleri içerisinde belirtilen gereksinimler için bile **Otomatik doğrulama** yapılabiliyor.
* Kompleks kimlik doğrulama sistemleri için destek, **database bağlantıları**, vs.
* **Taviz yok** hiçbir şeyden taviz vermeden, database frontend vs. Bütün hepsinin kolayca entegre edilebiliyor.

### Sınırsız "plug-inler"

Başka bir deyişle, plug-inlere ihtiyacımız yok, import edip direkt olarak kullanmaya başlayabiliriz.

    ]
}
```

you will get a text version, with:

```
1 validation error
path -> item_id
  value is not a valid integer (type=type_error.integer)
```

#### `RequestValidationError` vs `ValidationError`

!!! warning
    These are technical details that you might skip if it's not important for you now.

=== "Python 3.6+"

    ```Python hl_lines="19"
    {!> ../../../docs_src/dependencies/tutorial002.py!}
    ```

**FastAPI** 调用 `CommonQueryParams` 类。这将创建该类的一个 "实例"，该实例将作为参数 `commons` 被传递给你的函数。

## 类型注解 vs `Depends`

注意，我们在上面的代码中编写了两次`CommonQueryParams`：

```Python
commons: CommonQueryParams = Depends(CommonQueryParams)
```

最后的 `CommonQueryParams`:

```Python
... = Depends(CommonQueryParams)

    ```

**FastAPI** calls the `CommonQueryParams` class. This creates an "instance" of that class and the instance will be passed as the parameter `commons` to your function.

## Type annotation vs `Depends`

Notice how we write `CommonQueryParams` twice in the above code:

=== "Python 3.8+"

    ```Python
    commons: Annotated[CommonQueryParams, Depends(CommonQueryParams)]
    ```

## Tasarım

Sonrasında, (**FastAPI** kullanan bir geliştirici olarak) sahip olmak istediğim "API"ı tasarlamak için biraz zaman harcadım.

Çeşitli fikirleri en popüler Python editörlerinde test ettim: PyCharm, VS Code, Jedi tabanlı editörler.

    But as the content/parameter of that `List` is a Pydantic *model* with `orm_mode`, the data will be retrieved and returned to the client as normally, without problems.

### About `def` vs `async def`

Here we are using SQLAlchemy code inside of the *path operation function* and in the dependency, and, in turn, it will go and communicate with an external database.

That could potentially require some "waiting".

        }
    ]
}
```

eine Textversion:

```
1 validation error
path -> item_id
  value is not a valid integer (type=type_error.integer)
```

#### `RequestValidationError` vs. `ValidationError`

!!! warning "Achtung"
    Das folgende sind technische Details, die Sie überspringen können, wenn sie für Sie nicht wichtig sind.

Dann habe ich einige Zeit damit verbracht, die Entwickler-„API“ zu entwerfen, die ich als Benutzer haben wollte (als Entwickler, welcher FastAPI verwendet).

Ich habe mehrere Ideen in den beliebtesten Python-Editoren getestet: PyCharm, VS Code, Jedi-basierte Editoren.

  - author: William Hayes
    author_link: https://medium.com/@williamhayes
    link: https://medium.com/@williamhayes/fastapi-starlette-debug-vs-prod-5f7561db3a59
    title: FastAPI/Starlette debug vs prod
  - author: Mukul Mantosh
    author_link: https://twitter.com/MantoshMukul
    link: https://www.jetbrains.com/pycharm/guide/tutorials/fastapi-aws-kubernetes/

而且，最好的方式是使用现有的标准。

因此，甚至在开发 **FastAPI** 前，我就花了几个月的时间研究 OpenAPI、JSON Schema、OAuth2 等规范。深入理解它们之间的关系、重叠及区别之处。

## 设计

然后，我又花了一些时间从用户角度（使用 FastAPI 的开发者）设计了开发者 **API**。

同时，我还在最流行的 Python 代码编辑器中测试了很多思路，包括 PyCharm、VS Code、基于 Jedi 的编辑器。

根据最新 <a href="https://www.jetbrains.com/research/python-developers-survey-2018/#development-tools" class="external-link" target="_blank">Python 开发者调研报告</a>显示，这几种编辑器覆盖了约 80% 的用户。