# Messages to create or check
    new_translation_message = f"Good news everyone! 😉 There's a new translation PR to be reviewed: #{pr.number} by @{pr.user.login}. 🎉 This requires 2 approvals from native speakers to be merged. 🤓"
    done_translation_message = f"~There's a new translation PR to be reviewed: #{pr.number} by @{pr.user.login}~ Good job! This is done. 🍰☕"

    # Normally only one language, but still

!!! tip
    The `shutdown` would happen when you are **stopping** the application.

    Maybe you need to start a new version, or you just got tired of running it. 🤷

### Lifespan function

The first thing to notice, is that we are defining an async function with `yield`. This is very similar to Dependencies with `yield`.

```Python hl_lines="14-19"
{!../../../docs_src/events/tutorial003.py!}
```

read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

This way you write shared code once and **FastAPI** takes care of calling it for your *path operations*.

!!! check
    Notice that you don't have to create a special class and pass it somewhere to **FastAPI** to "register" it or anything similar.

    You just pass it to `Depends` and **FastAPI** knows how to do the rest.

<img src="/img/tutorial/extending-openapi/image03.png">

## Change the Theme

The same way you could set the syntax highlighting theme with the key `"syntaxHighlight.theme"` (notice that it has a dot in the middle):

```Python hl_lines="3"
{!../../../docs_src/configure_swagger_ui/tutorial002.py!}
```

That configuration would change the syntax highlighting color theme:

!!! tip
    Notice that the values you return are SQLAlchemy models, or lists of SQLAlchemy models.

    But as all the *path operations* have a `response_model` with Pydantic *models* / schemas using `orm_mode`, the data declared in your Pydantic models will be extracted from them and returned to the client, with all the normal filtering and validation.

!!! tip

    ```

=== "Python 3.8+"

    ```Python hl_lines="10"
    {!> ../../../docs_src/query_params_str_validations/tutorial002_an.py!}
    ```

Notice that the default value is still `None`, so the parameter is still optional.

```Python
something()
```

or

```Python
something(some_argument, some_keyword_argument="foo")
```

then it is a "callable".

## Classes as dependencies

You might notice that to create an instance of a Python class, you use that same syntax.

For example:

```Python
class Cat:
    def __init__(self, name: str):
        self.name = name


fluffy = Cat(name="Mr Fluffy")

    ```

!!! tip
    You can actually use this same technique with an HTTP `PUT` operation.

    But the example here uses `PATCH` because it was created for these use cases.

!!! note
    Notice that the input model is still validated.

    So, if you want to receive partial updates that can omit all the attributes, you need to have a model with all the attributes marked as optional (with default values or `None`).

    By doing it this way, we can put it in a `with` block, and that way, ensure that it is closed after finishing.

!!! tip
    Notice that here as we are using standard `open()` that doesn't support `async` and `await`, we declare the path operation with normal `def`.

### `FileResponse`

Asynchronously streams a file as the response.

```

</div>

这个命令会打开浏览器并自动验证身份。

## 使用 Deta 部署

接下来，使用 Deta CLI 部署应用：

<div class="termy">

```console
$ deta new

Successfully created a new micro

// Notice the "endpoint" 🔍

{
    "name": "fastapideta",
    "runtime": "python3.7",
    "endpoint": "https://qltnci.deta.dev",
    "visor": "enabled",
    "http_auth": "enabled"
}

Adding dependencies...