},
	ErrSTSNotInitialized: {
		Code:           "STSNotInitialized",
		Description:    "STS API not initialized, please try again.",
		HTTPStatusCode: http.StatusServiceUnavailable,
	},
	ErrSTSIAMNotInitialized: {
		Code:           "STSIAMNotInitialized",
		Description:    "STS IAM not initialized, please try again.",
		HTTPStatusCode: http.StatusServiceUnavailable,
	},
	ErrSTSUpstreamError: {

// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package str provides string manipulation utilities.
package str

import (
	"fmt"
	"strings"
	"unicode"
	"unicode/utf8"
)

// StringList flattens its arguments into a single []string.
// Each argument in args must have type string or []string.

```Python hl_lines="9"
{!../../../docs_src/query_params_str_validations/tutorial001.py!}
```

쿼리 매개변수 `q`는 `Optional[str]` 자료형입니다. 즉, `str` 자료형이지만 `None` 역시 될 수 있음을 뜻하고, 실제로 기본값은 `None`이기 때문에 FastAPI는 이 매개변수가 필수가 아니라는 것을 압니다.

!!! note "참고"
    FastAPI는 `q`의 기본값이 `= None`이기 때문에 필수가 아님을 압니다.

    `Optional[str]`에 있는 `Optional`은 FastAPI가 사용하는게 아니지만, 편집기에게 더 나은 지원과 오류 탐지를 제공하게 해줍니다.

## 추가 검증

		}
		return false, nil
	}
	return len(name) == 0, nil
}

// scanChunk gets the next segment of pattern, which is a non-star string
// possibly preceded by a star.
func scanChunk(pattern string) (star bool, chunk, rest string) {
	for len(pattern) > 0 && pattern[0] == '*' {
		pattern = pattern[1:]
		star = true
	}
	inrange := false
	var i int
Scan:
	for i = 0; i < len(pattern); i++ {
		switch pattern[i] {
		case '\\':

```

由于我们必须用 `Query(default=None)` 替换默认值 `None`，`Query` 的第一个参数同样也是用于定义默认值。

所以：

```Python
q: Union[str, None] = Query(default=None)
```

...使得参数可选，等同于：

```Python
q: str = None
```

但是 `Query` 显式地将其声明为查询参数。

然后，我们可以将更多的参数传递给 `Query`。在本例中，适用于字符串的 `max_length` 参数：

```Python
q: Union[str, None] = Query(default=None, max_length=50)
```

将会校验数据，在数据无效时展示清晰的错误信息，并在 OpenAPI 模式的*路径操作*中记录该参​​数。

    runTest("analysis/analysis-api/testData/components/typeInfoProvider/superTypes/regularClassWithBounds.kt");
  }

  @Test
  @TestMetadata("star.kt")
  public void testStar() {
    runTest("analysis/analysis-api/testData/components/typeInfoProvider/superTypes/star.kt");
  }

  @Test
  @TestMetadata("string.kt")
  public void testString() {

    runTest("analysis/analysis-api/testData/components/typeInfoProvider/superTypes/regularClassWithBounds.kt");
  }

  @Test
  @TestMetadata("star.kt")
  public void testStar() {
    runTest("analysis/analysis-api/testData/components/typeInfoProvider/superTypes/star.kt");
  }

  @Test
  @TestMetadata("string.kt")
  public void testString() {

    runTest("analysis/analysis-api/testData/components/typeInfoProvider/superTypes/regularClassWithBounds.kt");
  }

  @Test
  @TestMetadata("star.kt")
  public void testStar() {
    runTest("analysis/analysis-api/testData/components/typeInfoProvider/superTypes/star.kt");
  }

  @Test
  @TestMetadata("string.kt")
  public void testString() {

	c.processor.callbacks = append(c.processor.callbacks, c)
	return c.processor.compile()
}

// getRIndex get right index from string slice
func getRIndex(strs []string, str string) int {
	for i := len(strs) - 1; i >= 0; i-- {
		if strs[i] == str {
			return i
		}
	}
	return -1
}

func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
	var (
		names, sorted []string

	Sort(data)
	if !IsSorted(data) {
		t.Errorf("sorted %v", float64s)
		t.Errorf("   got %v", data)
	}
}

func TestSortStringSlice(t *testing.T) {
	data := Clone(strs[:])
	Sort(data)
	if !IsSorted(data) {
		t.Errorf("sorted %v", strs)
		t.Errorf("   got %v", data)
	}
}

func TestSortLarge_Random(t *testing.T) {
	n := 1000000
	if testing.Short() {
		n /= 100
	}
	data := make([]int, n)