该命令行程序 `fastapi` 就是 **FastAPI CLI**。

FastAPI CLI 接收你的 Python 程序路径，自动检测包含 FastAPI 的变量（通常命名为 `app`）及其导入方式，然后启动服务。

在生产环境中，你应该使用 `fastapi run` 命令。🚀

在内部，**FastAPI CLI** 使用了 <a href="https://www.uvicorn.dev" class="external-link" target="_blank">Uvicorn</a>，这是一个高性能、适用于生产环境的 ASGI 服务器。😎

## `fastapi dev`

当你运行 `fastapi dev` 时，它将以开发模式运行。

默认情况下，它会启用**自动重载**，因此当你更改代码时，它会自动重新加载服务器。该功能是资源密集型的，且相较不启用时更不稳定，因此你应该仅在开发环境下使用它。

 * 3.2.3 and earlier are encouraged to use {@link JavaToolchainImpl}.
 * <strong>Note:</strong> This is an internal component whose interface can change without prior notice.
 *
 * @deprecated clients that do not require compatibility with Maven 3.2.3 and earlier should link to
 *             {@link JavaToolchainImpl} instead.
 */
@Deprecated

`TestClient` 是基于 <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a> 的。幸运的是，我们可以直接使用它来测试API。

## 示例

举个简单的例子，让我们来看一个[更大的应用](../tutorial/bigger-applications.md){.internal-link target=_blank}和[测试](../tutorial/testing.md){.internal-link target=_blank}中描述的类似文件结构：

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

    /**
     * Resets this response to its initial state.
     */
    void reset();

    /**
     * Gets the exception associated with this response.
     *
     * @return an exception linked to an error
     */
    Exception getException();

    /**
     * Sets an exception for this response.
     *
     * @param e the exception to set
     */
    void exception(Exception e);

missing_translation_snippet = """
{!../../docs/missing-translation.md!}
"""

non_translated_sections = (
    f"reference{os.sep}",
    "release-notes.md",
    "fastapi-people.md",
    "external-links.md",
    "newsletter.md",
    "management-tasks.md",
    "management.md",
    "contributing.md",
)

docs_path = Path("docs")
en_docs_path = Path("docs/en")
en_config_path: Path = en_docs_path / mkdocs_name

    assertEquals("toArray() ordered contents: ", expected, asList(actual));
  }

  /**
   * Returns the {@link Method} instance for {@link #testToArray_isPlainObjectArray()} so that tests
   * of {@link Arrays#asList(Object[])} can suppress it with {@code
   * FeatureSpecificTestSuiteBuilder.suppressing()} until <a

   * {@link TypeVariableImpl}, the proxy calls the same method on its instance of {@code
   * TypeVariableImpl}. Otherwise it throws {@link UnsupportedOperationException}; this should only
   * apply to {@code getAnnotatedBounds()}. This does mean that users on Java who obtain an instance
   * of {@code TypeVariable} from {@link TypeResolver#resolveType} will not be able to call {@code

/**
 * The Exception class throw by the {@link Lookup} service.
 *
 * @since 4.0.0
 */
@Experimental
public class LookupException extends MavenException {

    public LookupException(String message) {
        super(message);
    }

    /**
     * @param message the message to give
     * @param e the {@link Exception}
     */
    public LookupException(String message, Exception e) {

/**
 * The subject-generator interface accepted by Collection testers, for testing a Collection at one
 * particular {@link CollectionSize}.
 *
 * <p>This interface should not be implemented outside this package; {@link
 * PerCollectionSizeTestSuiteBuilder} constructs instances of it from a more general {@link
 * TestCollectionGenerator}.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked

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