The `root_path` is used to handle these specific cases.

And it's also used internally when mounting sub-applications.

Having a proxy with a stripped path prefix, in this case, means that you could declare a path at `/app` in your code, but then, you add a layer on top (the proxy) that would put your **FastAPI** application under a path like `/api/v1`.

In this case, the original path `/app` would actually be served at `/api/v1/app`.

## Dependency Injection { #dependency-injection }

Using `BackgroundTasks` also works with the dependency injection system, you can declare a parameter of type `BackgroundTasks` at multiple levels: in a *path operation function*, in a dependency (dependable), in a sub-dependency, etc.

Se você estiver utilizando bibliotecas de terceiros que dizem para você chamar as funções com `await`, como:

```Python
results = await some_library()
```

Então, declare suas *funções de operação de rota* com `async def` como:

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results
```

/// note | Nota

Si te estás preguntando, "AlexNet", "ResNet" y "LeNet" son solo nombres de <abbr title="Técnicamente, arquitecturas de modelos de Deep Learning">modelos</abbr> de Machine Learning.

///

### Declarar un *path parameter* { #declare-a-path-parameter }

Luego crea un *path parameter* con una anotación de tipo usando la clase enum que creaste (`ModelName`):

{* ../../docs_src/path_params/tutorial005_py39.py hl[16] *}

## Поля-списки с параметром типа { #list-fields-with-type-parameter }

В Python есть специальный способ объявлять списки с внутренними типами, или «параметрами типа»:

### Объявите `list` с параметром типа { #declare-a-list-with-a-type-parameter }

Для объявления типов, у которых есть параметры типа (внутренние типы), таких как `list`, `dict`, `tuple`, передайте внутренний(ие) тип(ы) как «параметры типа», используя квадратные скобки: `[` и `]`

  echo 'If you have not, you will see a lot of undefined variable errors.'
else
  FROM_ENV=$(mktemp)
  # "export -p" prints a list of environment values in a safe-to-source format,
  # e.g. `declare -x TFCI_BAZEL_COMMON_ARGS="list of args"` for bash.
  export -p | grep TFCI > "$FROM_ENV"

  # Source the default ci values
  source ./ci/official/envs/ci_default

  # TODO(angerson) write this documentation

Each "scope" is just a string (without spaces).

They are normally used to declare specific security permissions, for example:

* `users:read` or `users:write` are common examples.
* `instagram_basic` is used by Facebook / Instagram.
* `https://www.googleapis.com/auth/drive` is used by Google.

/// info

In OAuth2 a "scope" is just a string that declares a specific permission required.

   * probably work around it by changing how we annotate the J2CL EnumMap, but that's probably more
   * trouble than just using Object.class.)
   *
   * Then we declare the getters for these fields as @GwtIncompatible so that no one can try to use
   * them under J2CL—or, as an unfortunate side effect, under GWT. We do still give the fields

## O que é "Injeção de Dependência" { #what-is-dependency-injection }

**"Injeção de Dependência"** no mundo da programação significa, que existe uma maneira de declarar no seu código (nesse caso, suas *funções de operação de rota*) para declarar as coisas que ele precisa para funcionar e que serão utilizadas: "dependências".

   * FeatureSpecificTestSuiteBuilder.suppressing()}.
   */
  /*
   * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
   * implementations are permitted to throw IAE if a hole is requested, and we could update
   * test*Hole to permit IAE. (But might this ignore genuine bugs?) But see the TODO above