`__name__ == "__main__"` 的主要目的是使用以下代码调用文件时执行一些代码：

<div class="termy">

```console
$ python myapp.py
```

</div>

而当其它文件导入它时并不会被调用，像这样：

```Python
from myapp import app
```

#### 更多细节

假设你的文件命名为 `myapp.py`。

如果你这样运行：

<div class="termy">

```console
$ python myapp.py
```

</div>

那么文件中由 Python 自动创建的内部变量 `__name__`，会将字符串 `"__main__"` 作为值。

package cmd

import (
	"bytes"
	"regexp"
	"testing"
)

// nolint: lll
var expectedOutput = `The following options can be passed to any command:
      --log_as_json: Whether to format output as JSON or in plain console-friendly format
      --log_caller: Comma-separated list of scopes for which to include caller information, scopes can be any of \[.*\]

# 第一步

最简单的 FastAPI 文件可能像下面这样：

```Python
{!../../../docs_src/first_steps/tutorial001.py!}
```

将其复制到 `main.py` 文件中。

运行实时服务器：

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
<span style="color: green;">INFO</span>:     Started reloader process [28720]

export MINIO_IDENTITY_OPENID_REDIRECT_URI="http://127.0.0.1:10000/oauth_callback"
minio server --address ":9001" --console-address ":10000" /tmp/minio1/{1...4} >/tmp/minio1_1.log 2>&1 &
site1_pid=$!
export MINIO_IDENTITY_OPENID_REDIRECT_URI="http://127.0.0.1:11000/oauth_callback"
minio server --address ":9002" --console-address ":11000" /tmp/minio2/{1...4} >/tmp/minio2_1.log 2>&1 &
site2_pid=$!

version: '3.7'

# Settings and configurations that are common for all containers
x-minio-common: &minio-common
  image: quay.io/minio/minio:${JOB_NAME}
  command: server --console-address ":9001" http://minio{1...4}/pdata{1...2} http://minio{5...8}/pdata{1...2}
  expose:
    - "9000"
    - "9001"
  environment:
    MINIO_CI_CD: "on"
    MINIO_ROOT_USER: "minio"
    MINIO_ROOT_PASSWORD: "minio123"

@rem End local scope for the variables with windows NT shell
if %ERRORLEVEL% equ 0 goto mainEnd

:fail
rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
rem the _cmd.exe /c_ return code!
set EXIT_CODE=%ERRORLEVEL%
if %EXIT_CODE% equ 0 set EXIT_CODE=1
if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
exit /b %EXIT_CODE%

:mainEnd
if "%OS%"=="Windows_NT" endlocal

//
// 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 types

// TargetType indicates type of the target e.g. console, http, kafka
type TargetType uint8

//go:generate stringer -type=TargetType -trimprefix=Target $GOFILE

// Constants for target types
const (
	_ TargetType = iota
	TargetConsole
	TargetHTTP
	TargetKafka

And then we use it when creating the `FastAPI` app.

Then you could disable OpenAPI (including the UI docs) by setting the environment variable `OPENAPI_URL` to the empty string, like:

<div class="termy">

```console
$ OPENAPI_URL= uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

## Install `WebSockets`

First you need to install `WebSockets`:

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets client

### In production

# WebSockets

您可以在 **FastAPI** 中使用 [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API)。

## 安装 `WebSockets`

首先，您需要安装 `WebSockets`：

```console
$ pip install websockets

---> 100%
```

## WebSockets 客户端

### 在生产环境中

在您的生产系统中，您可能使用现代框架（如React、Vue.js或Angular）创建了一个前端。

要使用 WebSockets 与后端进行通信，您可能会使用前端的工具。

或者，您可能有一个原生移动应用程序，直接使用原生代码与 WebSocket 后端通信。

或者，您可能有其他与 WebSocket 终端通信的方式。