///

## Types and Validation { #types-and-validation }

These environment variables can only handle **text strings**, as they are external to Python and have to be compatible with other programs and the rest of the system (and even with different operating systems, as Linux, Windows, macOS).

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

{* ../../docs_src/events/tutorial002_py39.py hl[6] *}

Here, the `shutdown` event handler function will write a text line `"Application shutdown"` to a file `log.txt`.

/// info

In the `open()` function, the `mode="a"` means "append", so, the line will be added after whatever is on that file, without overwriting the previous contents.

In your WebSocket route you can `await` for messages and send messages.

{* ../../docs_src/websockets/tutorial001_py39.py hl[48:52] *}

You can receive and send binary, text, and JSON data.

## Try it { #try-it }

If your file is named `main.py`, run your application with:

<div class="termy">

```console
$ fastapi dev main.py

## 運行程式碼

所有程式碼區塊都可以直接複製和使用（它們實際上是經過測試的 Python 檔案）。

要運行任何範例，請將程式碼複製到 `main.py` 檔案，並使用以下命令啟動 `fastapi dev`：

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

import com.google.common.escape.Escaper;
import com.google.common.escape.Escapers;

/**
 * {@code Escaper} instances suitable for strings to be included in XML attribute values and
 * elements' text contents. When possible, avoid manual escaping by using templating systems and
 * high-level APIs that provide autoescaping. For example, consider <a
 * href="http://www.xom.nu/">XOM</a>.
 *

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.nullValue;
import static org.junit.Assert.assertThat;

import java.sql.Time;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

import org.codelibs.core.misc.LocaleUtil;
import org.junit.After;
import org.junit.Before;

      .assertNoMoreLogs()
  }

  private fun request(): Request.Builder = Request.Builder().url(url)

  companion object {
    private val PLAIN = "text/plain".toMediaType()
  }

<%@page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<h2>検索方法</h2>
<dl>
	<dt>フィールド指定検索</dt>
	<dd>
		フィールド名の後にコロン : で指定した任意のフィールドで検索することができます。
		たとえば、ドキュメントの title フィールドで Fess を含むドキュメントを検索する場合は次のように入力します。
		<pre>title:Fess</pre>
		標準で利用可能なフィールドは url, host, site, title, content,
		content_length, last_modified および mimetype になります。
		設定で指定するフィールドは変更することができます。
	</dd>
	<dt>ソート</dt>
	<dd>
		sort 演算子は指定したフィールド名でドキュメントをソートします。

### Content Formats

#### Office Documents
- Microsoft Office (Word, Excel, PowerPoint)
- OpenOffice/LibreOffice documents
- RTF, WordPerfect

#### PDFs and Images
- PDF documents (text and metadata extraction)
- Images (JPEG, PNG, GIF, TIFF, BMP)
- Image metadata (EXIF, IPTC, XMP)

#### Archives and Compressed Files
- ZIP, TAR, GZ archives
- LHA compression format
- Nested archive extraction

                        boost:
                          type: string
                          example: "10.0"
                        mimetype:
                          type: string
                          example: "text/html"
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'