* `fixedquery`: has the exact value `fixedquery`.
* `$`: ends there, doesn't have any more characters after `fixedquery`.

If you feel lost with all these **"regular expression"** ideas, don't worry. They are a hard topic for many people. You can still do a lot of stuff without needing regular expressions yet.

Now you know that whenever you need them you can use them in **FastAPI**.

This can be used as a quick shortcut if you have only one Pydantic model and want to remove some data from the output.

/// tip

But it is still recommended to use the ideas above, using multiple classes, instead of these parameters.

    // we try hard to make them robust in practice.  We could additionally try to add in a system
    // load timeout multiplier.  Or we could try to use a CPU time bound instead of wall clock time
    // bound.  But these ideas are harder to implement.  We do not try to detect or handle a
    // user-specified -XX:+DisableExplicitGC.
    //
    // TODO(user): Consider using
    // java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()

Special thanks to [@nzig](https://github.com/nzig) for the core implementation and to [@adriangb](https://github.com/adriangb) for the inspiration and idea with [Xpresso](https://github.com/adriangb/xpresso)! 🚀

### Features

    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

Ещё раз: сделав такое объявление, с помощью **FastAPI** вы получите:

* Поддержку редакторов IDE (автодополнение и т.д), даже для вложенных моделей
* Преобразование данных
* Валидацию данных
* Автоматическую документацию

## Особые типы и валидация

Se não souber, você aprenderá o que é uma "senha hash" nos [capítulos de segurança](security/simple-oauth2.md#password-hashing){.internal-link target=_blank}.

///

## Múltiplos modelos

Aqui está uma ideia geral de como os modelos poderiam parecer com seus campos de senha e os lugares onde são usados:

{* ../../docs_src/extra_models/tutorial001.py hl[9,11,16,22,24,29:30,33:35,40:41] *}

### Sobre `**user_in.dict()`

    // we try hard to make them robust in practice.  We could additionally try to add in a system
    // load timeout multiplier.  Or we could try to use a CPU time bound instead of wall clock time
    // bound.  But these ideas are harder to implement.  We do not try to detect or handle a
    // user-specified -XX:+DisableExplicitGC.
    //
    // TODO(user): Consider using
    // java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()

        };
    try {
      Hashing.hmacMd5(badKey);
      fail();
    } catch (IllegalArgumentException expected) {
    } catch (NullPointerException toleratedOnAndroid) {
      // TODO(cpovirk): In an ideal world, we'd check here that we're running on Android.
    }
  }

  public void testEmptyInputs() throws Exception {
    String knownOutput = "8cbf764cbe2e4623d99a41354adfd390";

        // This test validates that paths which should be UNC but aren't detected due to normalization
        // still pass validation (which is the current behavior, though not ideal)

        // These paths normalize to \server\share which is NOT detected as UNC due to normalization
        String normalizedPath = noUncValidator.validatePath("\\\\\\\\server\\\\\\\\share");

{* ../../docs_src/handling_errors/tutorial006.py hl[2:5,15,21] *}