在这些情况下，你可以使用**自定义校验函数**，该函数会在正常校验之后应用（例如，在先校验值是 `str` 之后）。

你可以在 `Annotated` 中使用 [Pydantic 的 `AfterValidator`](https://docs.pydantic.dev/latest/concepts/validators/#field-after-validator) 来实现。

/// tip | 提示

Pydantic 还有 [`BeforeValidator`](https://docs.pydantic.dev/latest/concepts/validators/#field-before-validator) 等。🤓

///

![delete](https://raw.githubusercontent.com/minio/minio/master/docs/bucket/versioning/versioning_DELETE_versionEnabled.png)

Now the delete marker becomes the current version of the object. GET requests by default always retrieve the latest stored version. So performing a simple GET object request when the current version is a delete marker would return `404` `The specified key does not exist` as shown below:

      <version>1.0.0+</version>
      <description>Versioning information for "groupId/artifactId" or "groupId/artifactId/version" SNAPSHOT</description>
      <fields>
        <field>
          <name>latest</name>
          <version>1.0.0+</version>
          <type>String</type>

* 数据转换
* 数据校验
* 自动生成文档

## 特殊的类型和校验 { #special-types-and-validation }

除了普通的单一值类型（如 `str`、`int`、`float` 等）外，你还可以使用从 `str` 继承的更复杂的单一值类型。

要了解所有的可用选项，请查看 [Pydantic 的类型概览](https://docs.pydantic.dev/latest/concepts/types/)。你将在下一章节中看到一些示例。

例如，在 `Image` 模型中我们有一个 `url` 字段，我们可以把它声明为 Pydantic 的 `HttpUrl`，而不是 `str`：

{* ../../docs_src/body_nested_models/tutorial005_py310.py hl[2,8] *}

    FastAPI 框架，高效能，易於學習，快速開發，適用於生產環境
</p>
<p align="center">
<a href="https://github.com/fastapi/fastapi/actions?query=workflow%3ATest+event%3Apush+branch%3Amaster">
    <img src="https://github.com/fastapi/fastapi/actions/workflows/test.yml/badge.svg?event=push&branch=master" alt="Test">
</a>
<a href="https://coverage-badge.samuelcolvin.workers.dev/redirect/fastapi/fastapi">

/// info

If you already went through all the tutorial and came back to see more about types, a good resource is [the "cheat sheet" from `mypy`](https://mypy.readthedocs.io/en/latest/cheat_sheet_py3.html).

sleep 120

# List the objects from replicated site
echo "Objects from replicated site"
./mc ls minio2/test-bucket --insecure
count1=$(./mc ls minio2/test-bucket/obj --insecure | wc -l)
if [ "${count1}" -ne 1 ]; then
	echo "BUG: object minio1/test-bucket/obj not replicated"
	exit_1
fi

./mc put /tmp/data/custpartsize minio1/test-bucket --insecure --part-size 50MiB
sleep 120

# List the objects from source site
echo "Objects from source instance"
./mc ls minio1/test-bucket --insecure
count1=$(./mc ls minio1/test-bucket/encrypted --insecure | wc -l)
if [ "${count1}" -ne 1 ]; then
	echo "BUG: object minio1/test-bucket/encrypted not found"
	exit_1
fi

type DecryptRequest struct {
	// Name is the name of the master key used decrypt
	// the ciphertext.
	Name string

	// Version is the version of the master used for
	// decryption. If empty, the latest key version
	// is used.
	Version int

	// Ciphertext is the encrypted data that gets
	// decrypted.
	Ciphertext []byte

	// AssociatedData is the crypto. associated data.

mapred.maxthreads.generate.mapoutput=2 # Num threads to write map outputs
mapred.maxthreads.partition.closer=0 # Asynchronous map flushers
mapreduce.fileoutputcommitter.algorithm.version=2 # Use the latest committer version
mapreduce.job.reduce.slowstart.completedmaps=0.99 # 99% map, then reduce
mapreduce.reduce.shuffle.input.buffer.percent=0.9 # Min % buffer in RAM
mapreduce.reduce.shuffle.merge.percent=0.9 # Minimum % merges in RAM