=== "Python 3.10+"

    ```Python hl_lines="1  3  12-16"
    {!> ../../../docs_src/extra_data_types/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="1  3  12-16"
    {!> ../../../docs_src/extra_data_types/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="1  3  13-17"
    {!> ../../../docs_src/extra_data_types/tutorial001_an.py!}
    ```

        if (src == null) {
            return null;
        }
        if (src.getClass() == Date.class) {
            return (Date) src;
        }
        if (src instanceof Date) {
            return new Date(((Date) src).getTime());
        }
        if (src instanceof Calendar) {
            return new Date(((Calendar) src).getTimeInMillis());
        }
        final String str = src.toString();

=== "Python 3.10+"

    ```Python hl_lines="17  22  24-27"
    {!> ../../../docs_src/response_model/tutorial001_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="17  22  24-27"
    {!> ../../../docs_src/response_model/tutorial001_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="17  22  24-27"
    {!> ../../../docs_src/response_model/tutorial001.py!}
    ```

!!! note

You will see a simple page like:

<img src="/img/tutorial/websockets/image01.png">

You can type messages in the input box, and send them:

<img src="/img/tutorial/websockets/image02.png">

And your **FastAPI** application with WebSockets will respond back:

<img src="/img/tutorial/websockets/image03.png">

You can send (and receive) many messages:

<img src="/img/tutorial/websockets/image04.png">

您将看到一个简单的页面，如下所示：

<img src="/img/tutorial/websockets/image01.png">

您可以在输入框中输入消息并发送：

<img src="/img/tutorial/websockets/image02.png">

您的 **FastAPI** 应用程序将回复：

<img src="/img/tutorial/websockets/image03.png">

您可以发送（和接收）多条消息：

<img src="/img/tutorial/websockets/image04.png">

所有这些消息都将使用同一个 WebSocket 连

接。

## 使用 `Depends` 和其他依赖项

现在假设我们又一次正在创建这个函数，这次添加了类型提示。

在同样的地方，通过 `Ctrl+Space` 触发自动补全，你会发现：

<img src="https://fastapi.tiangolo.com/img/python-types/image02.png">

这样，你可以滚动查看选项，直到你找到看起来眼熟的那个：

<img src="https://fastapi.tiangolo.com/img/python-types/image03.png">

## 更多动机

下面是一个已经有类型提示的函数：

```Python hl_lines="1"
{!../../../docs_src/python_types/tutorial003.py!}
```

因为编辑器已经知道了这些变量的类型，所以不仅能对代码进行补全，还能检查其中的错误：

maven-it-plugin 0.1 maven-plugin Maven Integration Test Plugin A test plugin to assist testing of Maven core. 2009 maven-core-it file:///${basedir}/repo true true org.apache.maven maven-plugin-api 2.0 . pom.xml src/** src/main/resources src/main/java/org/apache/maven/plugins/coreit/AMojo.java src/main/java/org/apache/maven/plugins/coreit/AMojo.java package org.apache.maven.plugin.coreit; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the...

Beginnen wir mit einer einfachen FastAPI-Anwendung:

=== "Python 3.9+"

    ```Python hl_lines="7-9  12-13  16-17  21"
    {!> ../../../docs_src/generate_clients/tutorial001_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="9-11  14-15  18  19  23"
    {!> ../../../docs_src/generate_clients/tutorial001.py!}
    ```

maven-resources-plugin 0.1 maven-plugin Maven Integration Test Plugin A test plugin to assist testing of Maven core. 2009 maven-core-it file:///${basedir}/repo true true org.apache.maven maven-plugin-api 2.0 . pom.xml src/** src/main/resources src/main/java/org/apache/maven/plugins/coreit/ItMojo.java src/main/java/org/apache/maven/plugins/coreit/ItMojo.java package org.apache.maven.plugin.coreit; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the...

maven-compiler-plugin 0.1 maven-plugin Maven Integration Test Plugin A test plugin to assist testing of Maven core. 2009 maven-core-it file:///${basedir}/repo true true org.apache.maven maven-plugin-api 2.0 . pom.xml src/** src/main/resources src/main/java/org/apache/maven/plugins/coreit/ItMojo.java src/main/java/org/apache/maven/plugins/coreit/ItMojo.java package org.apache.maven.plugin.coreit; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the...