<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>
<font color="#3465A4">INFO    </font> Resolved absolute path <font color="#75507B">/home/user/code/awesomeapp/</font><font color="#AD7FA8">main.py</font>

 *
 * @since 4.0.0
 */
@Experimental
@Immutable
@SuppressWarnings("checkstyle:InterfaceIsType")
public interface ProjectScope extends ExtensibleEnum {

    /**
     * Main scope.
     */
    ProjectScope MAIN = projectScope("main");

    /**
     * Test scope.
     */
    ProjectScope TEST = projectScope("test");

# Advanced User Guide { #advanced-user-guide }

## Additional Features { #additional-features }

The main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} should be enough to give you a tour through all the main features of **FastAPI**.

In the next sections you will see other options, configurations, and additional features.

/// tip

The next sections are **not necessarily "advanced"**.

```

</div>

/// note | Hinweis

Der Befehl `uvicorn main:app` bezieht sich auf:

* `main`: die Datei `main.py` (das Python-„Modul“).
* `app`: das Objekt, das innerhalb von `main.py` mit der Zeile `app = FastAPI()` erstellt wurde.

Es ist äquivalent zu:

```Python
from main import app
```

///

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

In the file `main.py` you have your **FastAPI** app:


{* ../../docs_src/app_testing/app_a_py39/main.py *}

### Testing file { #testing-file }

    <jsp:include page="/WEB-INF/view/common/admin/sidebar.jsp">
        <jsp:param name="menuCategoryType" value="crawl"/>
        <jsp:param name="menuType" value="duplicateHost"/>
    </jsp:include>
    <main class="content-wrapper">
        <div class="content-header">
            <div class="container-fluid">
                <div class="row mb-2">
                    <div class="col-sm-6">
                        <h1>

```console
// Hier setzen wir die Umgebungsvariable noch nicht
$ python main.py

// Da wir die Umgebungsvariable nicht gesetzt haben, erhalten wir den Defaultwert

Hello World from Python

// Aber wenn wir zuerst eine Umgebungsvariable erstellen
$ export MY_NAME="Wade Wilson"

// Und dann das Programm erneut aufrufen
$ python main.py

// Jetzt kann es die Umgebungsvariable lesen

Hello Wade Wilson from Python

```

</div>

/// note

命令 `uvicorn main:app` 的含义如下：

* `main`：指的是 `main.py` 文件（即 Python “模块”）。
* `app`：指的是 `main.py` 文件中通过 `app = FastAPI()` 创建的对象。

它等价于以下导入语句：

```Python
from main import app
```

///

每种 ASGI 服务器程序通常都会有类似的命令，您可以在它们的官方文档中找到更多信息。

/// warning

Uvicorn 和其他服务器支持 `--reload` 选项，该选项在开发过程中非常有用。

maven-core-it file:///${basedir}/repo true true . pom.xml src/** src/main/resources src/main/java/org/apache/maven/its/mng3906/SomeClass.java src/main/java/org/apache/maven/its/mng3906/SomeClass.java package org.apache.maven.its.mng3906; public class SomeClass { } META-INF/maven/org.apache.maven.its.mng3906/e/pom.xml 4.0.0 org.apache.maven.its.mng3906 e 0.1 jar maven-core-it file:///${basedir}/repo true true . pom.xml src/** src/main/resources META-INF/maven/org.apache.maven.its.mng3906/e/pom.properties...

            attribute(DocsType.DOCS_TYPE_ATTRIBUTE, objects.named("gradle-source-folders"))
        }
        val main = sourceSets.main.get()
        main.java.srcDirs.forEach {
            outgoing.artifact(it)
        }
        main.groovy.srcDirs.forEach {
            outgoing.artifact(it)
        }
        main.resources.srcDirs.forEach {
            outgoing.artifact(it)
        }