///

## Embed a single body parameter { #embed-a-single-body-parameter }

Let's say you only have a single `item` body parameter from a Pydantic model `Item`.

By default, **FastAPI** will then expect its body directly.

But if you want it to expect a JSON with a key `item` and inside of it the model contents, as it does when you declare extra body parameters, you can use the special `Body` parameter `embed`:

```Python

import java.io.IOException
import okhttp3.Headers
import okhttp3.internal.delimiterOffset
import okhttp3.internal.trimSubstring
import org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

/**
 * Models the contents of a `Sec-WebSocket-Extensions` response header. OkHttp honors one extension
 * `permessage-deflate` and four parameters, `client_max_window_bits`, `client_no_context_takeover`,

 * under the License.
 */
package org.apache.maven.model.building;

import java.io.File;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;

import org.apache.maven.model.Model;
import org.apache.maven.model.Profile;
import org.apache.maven.model.resolution.ModelResolver;
import org.apache.maven.model.resolution.WorkspaceModelResolver;

/**

import org.apache.maven.api.DependencyScope;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.impl.resolver.RelocatedArtifact;
import org.apache.maven.model.Dependency;
import org.apache.maven.model.DependencyManagement;
import org.apache.maven.model.Exclusion;
import org.eclipse.aether.DefaultRepositorySystemSession;
import org.eclipse.aether.RepositorySystem;
import org.eclipse.aether.RepositorySystemSession;

* Recuperar os dados armazenados.
* Colocar esses dados em um modelo do Pydantic.
* Gerar um `dict` sem valores padrão a partir do modelo de entrada (usando `exclude_unset`).
    * Dessa forma, você pode atualizar apenas os valores definidos pelo usuário, em vez de substituir os valores já armazenados com valores padrão em seu modelo.

    }

    public MaxCodePoint(String userFriendly) {
      value = decode(userFriendly);
    }
  }

  /**
   * The default values of maxCodePoint below provide pretty good performance models of different
   * kinds of common human text.
   *
   * @see MaxCodePoint#decode
   */
  @Param({"0x80", "0x90", "0x100", "0x800", "0x10000", "0x10ffff"})
  MaxCodePoint maxCodePoint;

  @Param({"16384"})

/**
 * Provides access to the contents of a source independently of the
 * backing store (e.g. file system, database, memory).
 * <p>
 * This is mainly used to parse files into objects such as Maven projects,
 * models, settings, or toolchains. The source implementation handles
 * all the details of accessing the underlying content while providing
 * a uniform API to consumers.
 * <p>
 * Sources can represent:
 * <ul>

Обратите внимание, что это означает: «`one_person` — это **экземпляр** класса `Person`».

Это не означает: «`one_person` — это **класс** с именем `Person`».

## Pydantic-модели { #pydantic-models }

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> — это библиотека Python для валидации данных.

Вы объявляете «форму» данных как классы с атрибутами.

    Undefined,
    get_compat_model_name_map,
    get_definitions,
    get_schema_from_model_field,
    lenient_issubclass,
)
from fastapi.datastructures import DefaultPlaceholder
from fastapi.dependencies.models import Dependant
from fastapi.dependencies.utils import (
    _get_flat_fields_from_params,
    get_flat_dependant,
    get_flat_params,
    get_validation_alias,
)
from fastapi.encoders import jsonable_encoder

## Zusätzliche JSON-Schemadaten in Pydantic-Modellen { #extra-json-schema-data-in-pydantic-models }

Sie können `examples` („Beispiele“) für ein Pydantic-Modell deklarieren, welche dem generierten JSON-Schema hinzugefügt werden.

{* ../../docs_src/schema_extra_example/tutorial001_py310.py hl[13:24] *}

Diese zusätzlichen Informationen werden unverändert zum für dieses Modell ausgegebenen **JSON-Schema** hinzugefügt und in der API-Dokumentation verwendet.