如果你查看 FastAPI 的线上文档网站，会看到每种语言都有所有的文档页面，但是某些页面并未被翻译并且会有一处关于缺少翻译的提示。（但是当你像上面这样在本地运行文档时，你只会看到已经翻译的页面。）

现在假设你要为 [Features](features.md){.internal-link target=_blank} 章节添加翻译。

* 复制下面的文件：

```
docs/en/docs/features.md
```

* 粘贴到你想要翻译语言目录的相同位置，比如：

```
docs/es/docs/features.md
```

!!! tip
    注意路径和文件名的唯一变化是语言代码，从 `en` 更改为 `es`。

回到浏览器你就可以看到刚刚更新的章节了。🎉

And `threading.local` is not compatible with the new async features of modern Python.

!!! note "Technical Details"
    `threading.local` is used to have a "magic" variable that has a different value for each thread.

You can subscribe to the (infrequent) [**FastAPI and friends** newsletter](newsletter.md){.internal-link target=_blank} to stay updated about:

* News about FastAPI and friends 🚀
* Guides 📝
* Features ✨
* Breaking changes 🚨
* Tips and tricks ✅

## Follow FastAPI on Twitter

しかし、このようにローカルで実行すると、翻訳済みのページのみが表示されます。

ここで、セクション[Features](features.md){.internal-link target=_blank}の翻訳を追加するとします。

* 下記のファイルをコピーします:

```
docs/en/docs/features.md
```

* 翻訳したい言語のまったく同じところに貼り付けます。例えば:

```
docs/es/docs/features.md
```

!!! tip "豆知識"
    パスとファイル名の変更は、`en`から`es`への言語コードだけであることに注意してください。

* ここで、英語のMkDocs構成ファイルを開きます:

The key features are:

* **Fast**: Very high performance, on par with **NodeJS** and **Go** (thanks to Starlette and Pydantic). [One of the fastest Python frameworks available](#performance).
* **Fast to code**: Increase the speed to develop features by about 200% to 300%. *
* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. *

  - name: Question or Problem
    about: Ask a question or ask about a problem in GitHub Discussions.
    url: https://github.com/tiangolo/fastapi/discussions/categories/questions
  - name: Feature Request
    about: To suggest an idea or ask about a feature, please start with a question saying what you would like to achieve. There might be a way to do it already.
    url: https://github.com/tiangolo/fastapi/discussions/categories/questions

    # to support it as a first class "feature"
    assert is_bytes_sequence_annotation(Union[List[str], List[bytes]])


def test_is_uploadfile_sequence_annotation():
    # For coverage
    # TODO: in theory this would allow declaring types that could be lists of UploadFile
    # and other types, but I'm not even sure it's a good idea to support it as a first
    # class "feature"

The key features are:

* **Fast**: Very high performance, on par with **NodeJS** and **Go** (thanks to Starlette and Pydantic). [One of the fastest Python frameworks available](#performance).
* **Fast to code**: Increase the speed to develop features by about 200% to 300%. *
* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. *

        I'm asking this because answering questions and solving problems in GitHub is what consumes most of the time.

        I end up not being able to add new features, fix bugs, review pull requests, etc. as fast as I wish because I have to spend too much time handling questions.

# Tutorial - User Guide

This tutorial shows you how to use **FastAPI** with most of its features, step by step.

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference.

So you can come back and see exactly what you need.

## Run the code