/// tip

Pydantic có một hành vi đặc biệt khi bạn sử dụng `Optional` hoặc `Union[Something, None]` mà không có giá trị mặc dịnh, bạn có thể đọc nhiều hơn về nó trong tài liệu của Pydantic về <a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">Required Optional fields</a>.

///

## Type Hints với Metadata Annotations

  // either be pods that are running but not yet available or pods that still have not been created.
  // +optional
  optional int32 unavailableReplicas = 5;

  // Conditions represent the latest available observations of a deployment's current state.
  // +patchMergeKey=type
  // +patchStrategy=merge
  repeated DeploymentCondition conditions = 6;

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.

	// Content-Md5 is required should be set
	// http://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html
	if _, ok := r.Header[xhttp.ContentMD5]; !ok {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrMissingContentMD5), r.URL)
		return
	}

	// Content-Length is required and should be non-zero
	// http://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html
	if r.ContentLength <= 0 {

aws_access_key_id = minio
aws_secret_access_key = minio123
EOF

# Create certificates for TLS enabled MinIO
echo -n "Setup certs for MinIO instances ..."
wget -O certgen https://github.com/minio/certgen/releases/latest/download/certgen-linux-amd64 && chmod +x certgen
./certgen --host localhost
mkdir -p /tmp/certs
mv public.crt /tmp/certs || sudo mv public.crt /tmp/certs
mv private.key /tmp/certs || sudo mv private.key /tmp/certs
echo "done"

TEST_MINIO_ENC_KEY="MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDA"

# Create certificates for TLS enabled MinIO
echo -n "Setup certs for MinIO instances ..."
wget -O certgen https://github.com/minio/certgen/releases/latest/download/certgen-linux-amd64 && chmod +x certgen
./certgen --host localhost
mkdir -p /tmp/certs
mv public.crt /tmp/certs || sudo mv public.crt /tmp/certs
mv private.key /tmp/certs || sudo mv private.key /tmp/certs
echo "done"

Bijkomende optionele afhankelijkheden voor Pydantic:

* <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" target="_blank"><code>pydantic-settings</code></a> - voor het beheren van settings.
* <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> - voor extra data types die gebruikt kunnen worden met Pydantic.

```

### `RequestValidationError` vs `ValidationError`

/// warning | "警告"

如果您觉得现在还用不到以下技术细节，可以先跳过下面的内容。

///

`RequestValidationError` 是 Pydantic 的 <a href="https://docs.pydantic.dev/latest/concepts/models/#error-handling" class="external-link" target="_blank">`ValidationError`</a> 的子类。

**FastAPI** 调用的就是 `RequestValidationError` 类，因此，如果在 `response_model` 中使用 Pydantic 模型，且数据有错误时，在日志中就会看到这个错误。

/// tip | Dica

O SQLModel terá utilitários de migração envolvendo o Alembic, mas por enquanto, você pode usar o <a href="https://alembic.sqlalchemy.org/en/latest/" class="external-link" target="_blank">Alembic</a> diretamente.

///

### Criar um Hero

/// info

Wenn Sie bereits das ganze Tutorial durchgearbeitet haben und mehr über Typen erfahren wollen, dann ist eine gute Ressource <a href="https://mypy.readthedocs.io/en/latest/cheat_sheet_py3.html" class="external-link" target="_blank">der „Cheat Sheet“ von `mypy`</a>.