```

////

With this, we get tooling support, from editors and mypy as this code is correct in terms of types, but we also get the data filtering from FastAPI.

How does this work? Let's check that out. 🤓

### Type Annotations and Tooling

First let's see how editors, mypy and other tools would see this.

I tested several ideas in the most popular Python editors: PyCharm, VS Code, Jedi based editors.

By the last <a href="https://www.jetbrains.com/research/python-developers-survey-2018/#development-tools" class="external-link" target="_blank">Python Developer Survey</a>, that covers about 80% of the users.

<img src="/img/tutorial/body/image05.png">

/// tip

If you use <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a> as your editor, you can use the <a href="https://github.com/koxudaxi/pydantic-pycharm-plugin/" class="external-link" target="_blank">Pydantic PyCharm Plugin</a>.

It improves editor support for Pydantic models, with:

* auto-completion

///

Auf diese Weise kann Ihr Editor Sie auch bei der Bearbeitung von Einträgen aus der Liste unterstützen:

<img src="/img/python-types/image05.png">

Ohne Typen ist das fast unmöglich zu erreichen.

Beachten Sie, dass die Variable `item` eines der Elemente in der Liste `items` ist.

Und trotzdem weiß der Editor, dass es sich um ein `str` handelt, und bietet entsprechende Unterstützung.

<img src="/img/tutorial/body/image05.png">

/// tip | "Tipp"

Wenn Sie <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a> als Ihren Editor verwenden, probieren Sie das <a href="https://github.com/koxudaxi/pydantic-pycharm-plugin/" class="external-link" target="_blank">Pydantic PyCharm Plugin</a> aus.

/// tip | "Tipp"

Wenn Sie in Ihrem Editor strikte Typchecks haben, mypy, usw., können Sie den Funktions-Rückgabetyp als <abbr title='„Irgend etwas“'>`Any`</abbr> deklarieren.

    set("k1", "a", "a")

    // Create an editor for k1. Detach it by clearing the cache.
    val editor = cache.edit("k1")!!
    editor.setString(0, "bb")
    editor.setString(1, "bb")
    cache.evictAll()

    // Create a new value in its place.
    set("k1", "ccc", "ccc")
    assertThat(cache.size()).isEqualTo(6)

So kann ihr Editor Sie unterstützen:

* in <a href="https://code.visualstudio.com/" class="external-link" target="_blank">Visual Studio Code</a>:

![Editor Unterstützung](https://fastapi.tiangolo.com/img/vscode-completion.png)

* in <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>:

///

By doing that, your editor can provide support even while processing items from the list:

<img src="/img/python-types/image05.png">

Without types, that's almost impossible to achieve.

Notice that the variable `item` is one of the elements in the list `items`.

And still, the editor knows it is a `str`, and provides support for that.

#### Tuple and Set

You will rarely need to come back to the docs.

Here's how your editor might help you:

* in <a href="https://code.visualstudio.com/" class="external-link" target="_blank">Visual Studio Code</a>:

![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png)

* in <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>:

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)