# General - How To - Recipes

Here are several pointers to other places in the docs, for general or frequent questions.

## Filter Data - Security

To ensure that you don't return more data than you should, read the docs for [Tutorial - Response Model - Return Type](../tutorial/response-model.md){.internal-link target=_blank}.

## Documentation Tags - OpenAPI

使用 `shutdown` 事件声明 `app` 关闭时运行的函数：

```Python hl_lines="6"
{!../../docs_src/events/tutorial002.py!}
```

此处，`shutdown` 事件处理器函数在 `log.txt` 中写入一行文本 `Application shutdown`。

/// info | "说明"

`open()` 函数中，`mode="a"` 指的是**追加**。因此这行文本会添加在文件已有内容之后，不会覆盖之前的内容。

///

/// tip | "提示"

注意，本例使用 Python `open()` 标准函数与文件交互。

这个函数执行 I/O（输入/输出）操作，需要等待内容写进磁盘。

但 `open()` 函数不支持使用 `async` 与 `await`。

 * {@code Iterable}. Except as noted, each method has a corresponding {@link Iterator}-based method
 * in the {@link Iterators} class.
 *
 * <p><b>Java 8+ users:</b> several common uses for this class are now more comprehensively
 * addressed by the new {@link java.util.stream.Stream} library. Read the method documentation below
 * for comparisons. This class is not being deprecated, but we gently encourage you to migrate to
 * streams.
 *

// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"context"
	"errors"

      if (rule[0][0] == EXCEPTION_MARKER) {
        // Exception rules hold the effective TLD plus one.
        domainLabels.size - rule.size
      } else {
        // Otherwise the rule is for a public suffix, so we must take one more label.
        domainLabels.size - (rule.size + 1)
      }

    return splitDomain(domain).asSequence().drop(firstLabelOffset).joinToString(".")
  }

  private fun splitDomain(domain: String): List<String> {

   * specified array and the size of the specified collection.
   *
   * <p>If the collection fits in the specified array with room to spare (i.e., the array has more
   * elements than the collection), the element in the array immediately following the end of the
   * collection is set to {@code null}. This is useful in determining the length of the collection

  palette:
  - media: "(prefers-color-scheme)"
    toggle:
      icon: material/lightbulb-auto
      name: Switch to light mode
  - media: '(prefers-color-scheme: light)'
    scheme: default
    primary: teal
    accent: amber
    toggle:
      icon: material/lightbulb
      name: Switch to dark mode
  - media: '(prefers-color-scheme: dark)'
    scheme: slate
    primary: teal
    accent: amber
    toggle:

    }
    return -1;
  }

  /**
   * Returns the start position of the first occurrence of the specified {@code target} within
   * {@code array}, or {@code -1} if there is no such occurrence.
   *
   * <p>More formally, returns the lowest index {@code i} such that {@code Arrays.copyOfRange(array,
   * i, i + target.length)} contains exactly the same elements as {@code target}.
   *

    }
    return -1;
  }

  /**
   * Returns the start position of the first occurrence of the specified {@code target} within
   * {@code array}, or {@code -1} if there is no such occurrence.
   *
   * <p>More formally, returns the lowest index {@code i} such that {@code Arrays.copyOfRange(array,
   * i, i + target.length)} contains exactly the same elements as {@code target}.
   *

import java.util.Map;
import java.util.Random;
import java.util.Set;
import junit.framework.TestCase;

/**
 * Tests that the different algorithms benchmarked in {@link QuantilesBenchmark} are actually all
 * returning more-or-less the same answers.
 */
public class QuantilesAlgorithmTest extends TestCase {

  private static final Random RNG = new Random(82674067L);
  private static final int DATASET_SIZE = 1000;