///

/// tip | "提示"

注意，模型属性的类型、默认值及 `Field` 的代码结构与*路径操作函数*的参数相同，只不过是用 `Field` 替换了`Path`、`Query`、`Body`。

///

## 添加更多信息

`Field`、`Query`、`Body` 等对象里可以声明更多信息，并且 JSON Schema 中也会集成这些信息。

*声明示例*一章中将详细介绍添加更多信息的知识。

## 小结

Pydantic 的 `Field` 可以为模型属性声明更多校验和元数据。

	public static final field INSTANCE Lmockwebserver3/SocketPolicy$DisconnectAtStart;
}

public final class mockwebserver3/SocketPolicy$DisconnectDuringRequestBody : mockwebserver3/SocketPolicy {
	public static final field INSTANCE Lmockwebserver3/SocketPolicy$DisconnectDuringRequestBody;
}

public final class mockwebserver3/SocketPolicy$DisconnectDuringResponseBody : mockwebserver3/SocketPolicy {

func (z *BatchJobKV) DecodeMsg(dc *msgp.Reader) (err error) {
	var field []byte
	_ = field
	var zb0001 uint32
	zb0001, err = dc.ReadMapHeader()
	if err != nil {
		err = msgp.WrapError(err)
		return
	}
	for zb0001 > 0 {
		zb0001--
		field, err = dc.ReadMapKeyPtr()
		if err != nil {
			err = msgp.WrapError(err)
			return
		}
		switch msgp.UnsafeString(field) {
		case "Key":
			z.Key, err = dc.ReadString()

## Importe `Field`

Primeiro, você tem que importá-lo:

```Python hl_lines="4"
{!../../docs_src/body_fields/tutorial001.py!}
```

/// warning | "Aviso"

Note que `Field` é importado diretamente do `pydantic`, não do `fastapi` como todo o resto (`Query`, `Path`, `Body`, etc).

///

            builder.field(SESSION_ID, sessionId);
        }
        if (method != null) {
            builder.field(METHOD, method);
        }
        if (url != null) {
            builder.field(URL, url);
        }
        if (parentUrl != null) {
            builder.field(PARENT_URL, parentUrl);
        }
        if (depth != null) {
            builder.field(DEPTH, depth);
        }

          <required>true</required>
          <type>String</type>
        </field>
        <field>
          <name>version</name>
          <description>The version of the extension.</description>
          <version>1.0.0+</version>
          <required>true</required>
          <type>String</type>
        </field>
        <field>
          <name>classLoadingStrategy</name>

                    "type": "missing",
                    "loc": ["body", "item"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "user"],
                    "msg": "Field required",
                    "input": None,
                },
                {

                    "type": "missing",
                    "loc": ["body", "item"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "user"],
                    "msg": "Field required",
                    "input": None,
                },
                {

                    "type": "missing",
                    "loc": ["body", "item"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "user"],
                    "msg": "Field required",
                    "input": None,
                },
                {

            {
                "type": "missing",
                "loc": ["body", "username"],
                "msg": "Field required",
                "input": {},
            },
            {
                "type": "missing",
                "loc": ["body", "password"],
                "msg": "Field required",
                "input": {},
            },
        ]
    }


@needs_pydanticv2
@needs_py39