Any variable that is put inside of `{}` in an f-string will be expanded / injected in the string.

### `dict` unpacking

In fact, those blocks of code are not written inside the Markdown, they are Python files in the `./docs_src/` directory.

And those Python files are included/injected in the documentation when generating the site.

### Docs for tests

Most of the tests actually run against the example source files in the documentation.

This helps to make sure that:

                                    },
                                    "invalid": {
                                        "summary": "Invalid data is rejected with an error",
                                        "value": {
                                            "name": "Baz",
                                            "price": "thirty five point four",

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

    ```Python hl_lines="19-22  26-27"
    {!> ../../../docs_src/security/tutorial002.py!}
    ```

## Inject the current user

So now we can use the same `Depends` with our `get_current_user` in the *path operation*:

=== "Python 3.10+"

    ```Python hl_lines="31"

Only the code prior to and including the `yield` statement is executed before creating a response:

```Python hl_lines="2-4"
{!../../../docs_src/dependencies/tutorial007.py!}
```

The yielded value is what is injected into *path operations* and other dependencies:

```Python hl_lines="4"
{!../../../docs_src/dependencies/tutorial007.py!}
```

The code following the `yield` statement is executed after the response has been delivered:

Das System (in diesem Fall **FastAPI**) kümmert sich dann darum, Ihren Code mit den erforderlichen Abhängigkeiten zu versorgen („die Abhängigkeiten einfügen“ – „inject the dependencies“).

Das ist sehr nützlich, wenn Sie:

* Eine gemeinsame Logik haben (die gleiche Code-Logik immer und immer wieder).
* Datenbankverbindungen teilen.

    ```Python hl_lines="1  4-6" title="app/dependencies.py"
    {!> ../../../docs_src/bigger_applications/app/dependencies.py!}
    ```

!!! tip
    We are using an invented header to simplify this example.

    But in real cases you will get better results using the integrated [Security utilities](security/index.md){.internal-link target=_blank}.

## Another module with `APIRouter`

* Add support for `response_model_exclude_defaults` and `response_model_exclude_none`:
    * Deprecate the parameter `include_none` in `jsonable_encoder` and add the inverted `exclude_none`, to keep in sync with Pydantic.
    * PR [#1166](https://github.com/tiangolo/fastapi/pull/1166) by [@voegtlel](https://github.com/voegtlel).

                        "name": "Bar",
                        "price": "35.4",
                    },
                },
                "invalid": {
                    "summary": "Invalid data is rejected with an error",
                    "value": {
                        "name": "Baz",
                        "price": "thirty five point four",
                    },
                },
            },
        ),

                        "name": "Bar",
                        "price": "35.4",
                    },
                },
                "invalid": {
                    "summary": "Invalid data is rejected with an error",
                    "value": {
                        "name": "Baz",
                        "price": "thirty five point four",
                    },
                },
            },
        ),