///

```Python hl_lines="1"
async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
    return {"fresh_value": fresh_value}
```

////

## Recap { #recap }

Apart from all the fancy words used here, the **Dependency Injection** system is quite simple.

Just functions that look the same as the *path operation functions*.

<img src="/img/tutorial/path-operation-configuration/image04.png">

Check how deprecated and non-deprecated *path operations* look like:

<img src="/img/tutorial/path-operation-configuration/image05.png">

## Recap { #recap }

Like `stored_item_model.model_copy(update=update_data)`:

{* ../../docs_src/body_updates/tutorial002_py310.py hl[33] *}

### Partial updates recap { #partial-updates-recap }

In summary, to apply partial updates you would:

* (Optionally) use `PATCH` instead of `PUT`.
* Retrieve the stored data.
* Put that data in a Pydantic model.

But if you need to access variables and objects from the same **FastAPI** app, or you need to perform small background tasks (like sending an email notification), you can simply just use `BackgroundTasks`.

## Recap { #recap }

So, `0.5` would be a valid value. But `0.0` or `0` would not.

And the same for <abbr title="less than"><code>lt</code></abbr>.

{* ../../docs_src/path_params_numeric_validations/tutorial006_an_py39.py hl[13] *}

## Recap { #recap }

///

## Resumen { #recap }

In this case, you can use `typing.Dict` (or just `dict` in Python 3.9 and above):

{* ../../docs_src/extra_models/tutorial005_py39.py hl[6] *}

## Recap { #recap }

Use multiple Pydantic models and inherit freely for each case.

///

## Resumen { #recap }

Puedes utilizar `Field` de Pydantic para declarar validaciones adicionales y metadatos para los atributos del modelo.

Esto no es una limitación de **FastAPI**, es parte del protocolo HTTP.

///

## Recapitulación { #recap }

Esto no es una limitación de **FastAPI**, es parte del protocolo HTTP.

///

## Resumen { #recap }