```Python hl_lines="7"
    {!> ../../../docs_src/path_params_numeric_validations/tutorial002.py!}
    ```

But keep in mind that if you use `Annotated`, you won't have this problem, it won't matter as you're not using the function parameter default values for `Query()` or `Path()`.

=== "Python 3.9+"

    ```Python hl_lines="10"

But you can disable it by setting `syntaxHighlight` to `False`:

```Python hl_lines="3"
{!../../../docs_src/configure_swagger_ui/tutorial001.py!}
```

...and then Swagger UI won't show the syntax highlighting anymore:

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

## Change the Theme

This also means that if you are inside a utility function that you are calling inside of your *path operation function*, and you raise the `HTTPException` from inside of that utility function, it won't run the rest of the code in the *path operation function*, it will terminate that request right away and send the HTTP error from the `HTTPException` to the client.

The same way, you could raise an `HTTPException` or similar in the exit code, after the `yield`.

!!! tip

    This is a somewhat advanced technique, and in most of the cases you won't really need it, as you can raise exceptions (including `HTTPException`) from inside of the rest of your application code, for example, in the *path operation function*.

    But it's there for you if you need it. 🤓

```

In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python
    commons: CommonQueryParams ...
    ```

...doesn't have any special meaning for **FastAPI**. FastAPI won't use it for data conversion, validation, etc. (as it is using the `Depends(CommonQueryParams)` for that).

You could actually write just:

=== "Python 3.8+"

    ```Python

So, the user will also have a `password` when creating it.

But for security, the `password` won't be in other Pydantic *models*, for example, it won't be sent from the API when reading a user.

=== "Python 3.10+"

    ```Python hl_lines="1  4-6  9-10  21-22  25-26"
    {!> ../../../docs_src/sql_databases/sql_app_py310/schemas.py!}

```

⏮️ `async def`, 🐍 💭 👈, 🔘 👈 🔢, ⚫️ ✔️ 🤔 `await` 🧬, & 👈 ⚫️ 💪 "⏸" ⏸ 🛠️ 👈 🔢 & 🚶 🕳 🙆 👶 ⏭ 👟 🔙.

🕐❔ 👆 💚 🤙 `async def` 🔢, 👆 ✔️ "⌛" ⚫️. , 👉 🏆 🚫 👷:

```Python
# This won't work, because get_burgers was defined with: async def
burgers = get_burgers(2)
```

---

, 🚥 👆 ⚙️ 🗃 👈 💬 👆 👈 👆 💪 🤙 ⚫️ ⏮️ `await`, 👆 💪 ✍ *➡ 🛠️ 🔢* 👈 ⚙️ ⚫️ ⏮️ `async def`, 💖:

!!! tip
    `JSONResponse` itself is a sub-class of `Response`.

And when you return a `Response`, **FastAPI** will pass it directly.

It won't do any data conversion with Pydantic models, it won't convert the contents to any type, etc.

This gives you a lot of flexibility. You can return any data type, override any data declaration or validation, etc.

```Python hl_lines="2  7  19"
{!../../../docs_src/custom_response/tutorial003.py!}
```

!!! warning
    A `Response` returned directly by your *path operation function* won't be documented in OpenAPI (for example, the `Content-Type` won't be documented) and won't be visible in the automatic interactive docs.

!!! info
    Of course, the actual `Content-Type` header, status code, etc, will come from the `Response` object you returned.