////

/// info | Informação

Para saber mais sobre o <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic, verifique a sua documentação</a>.

///

O **FastAPI** é todo baseado em Pydantic.

Você verá muito mais disso na prática no [Tutorial - Guia do usuário](tutorial/index.md){.internal-link target=_blank}.

/// tip | Dica

Python'un önceki sürümlerinde, threadlerı veya <a href="https://www.gevent.org/" class="external-link" target="_blank">Gevent</a> kullanıyor olabilirdin. Ancak kodu anlamak, hata ayıklamak ve düşünmek çok daha karmaşık olurdu.

NodeJS / Browser JavaScript'in önceki sürümlerinde, "callback" kullanırdınız. Bu da <a href="http://callbackhell.com/" class="external-link" target="_blank">callbacks cehennemine</a> yol açar.

## Coroutine'ler

```

////

/// info

To use `EmailStr`, first install <a href="https://github.com/JoshData/python-email-validator" class="external-link" target="_blank">`email-validator`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install email-validator
```

or with:

```console

```Python hl_lines="27-31"
{!../../docs_src/app_testing/tutorial002.py!}
```

/// note

For more details, check Starlette's documentation for <a href="https://www.starlette.io/testclient/#testing-websocket-sessions" class="external-link" target="_blank">testing WebSockets</a>.

在這裡，你將會看到**不同主題**的範例或「如何使用」的指南。

大多數這些想法都是**獨立**的，在大多數情況下，你只需要研究那些直接適用於**你的專案**的東西。

如果有些東西看起來很有趣且對你的專案很有用的話再去讀它，否則你可能可以跳過它們。

/// tip

如果你想要以結構化的方式**學習 FastAPI**（推薦），請前往[教學 - 使用者指南](../tutorial/index.md){.internal-link target=_blank}逐章閱讀。

```Python hl_lines="7"
{!../../docs_src/query_params_str_validations/tutorial006b.py!}
```

/// info

🚥 👆 🚫 👀 👈 `...` ⏭: ⚫️ 🎁 👁 💲, ⚫️ <a href="https://docs.python.org/3/library/constants.html#Ellipsis" class="external-link" target="_blank">🍕 🐍 &amp; 🤙 "❕"</a>.

⚫️ ⚙️ Pydantic &amp; FastAPI 🎯 📣 👈 💲 ✔.

///

👉 🔜 ➡️ **FastAPI** 💭 👈 👉 🔢 ✔.

### ✔ ⏮️ `None`

Se você utiliza uma versão anterior, ocorrerão erros ao tentar utilizar `Annotated`.

Certifique-se de [Atualizar a versão do FastAPI](../../deployment/versions.md#atualizando-as-versoes-do-fastapi){.internal-link target=_blank} para pelo menos 0.95.1 antes de usar `Annotated`.

///

### Importando `Depends`

//// tab | Python 3.10+

```Python hl_lines="3"

import java.util.NoSuchElementException;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code remove()} operations on a queue. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * A {@code TearDownStack} contains a stack of {@link TearDown} instances.
 *
 * <p>This class is thread-safe.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

import org.apache.maven.model.building.ModelProblem.Severity;
import org.apache.maven.model.building.ModelProblem.Version;

/**
 * Class to wrap request parameters to ModelProblemCollector.addProblem
 *
 * @deprecated use {@link org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")
public final class ModelProblemCollectorRequest {

    private final ModelProblem.Severity severity;