...desde:

```Python
        ... "item_name": item.name ...
```

...a:

```Python
        ... "item_price": item.price ...
```

...y observa cómo tu editor autocompleta los atributos y conoce sus tipos:

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

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 { #type-annotations-and-tooling }

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

<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

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.

    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)

///

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.

/// tip

Some editors check for unused function parameters, and show them as errors.

Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.

///

### Editor support { #editor-support }

All the framework was designed to be easy and intuitive to use, all the decisions were tested on multiple editors even before starting development, to ensure the best development experience.

  internal fun completeEdit(
    editor: Editor,
    success: Boolean,
  ) {
    val entry = editor.entry
    check(entry.currentEditor == editor)

    // If this edit is creating the entry for the first time, every index must have a value.
    if (success && !entry.readable) {
      for (i in 0 until valueCount) {
        if (!editor.written!![i]) {
          editor.abort()

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

But then we get a `dict` in the parameter `commons` of the *path operation function*.

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 { #what-makes-a-dependency }