```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

<a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> の第2引数は、デフォルトで返される値を指定します。

この引数を省略するとデフォルト値として`None`が返されますが、ここではデフォルト値として`"World"`を指定しています。

///

次に、このPythonプログラムを呼び出します。

//// tab | Linux, macOS, Windows Bash

### 당신만의 비동기 코드 작성하기

Starlette(그리고 FastAPI)는 <a href="https://anyio.readthedocs.io/en/stable/" class="external-link" target="_blank">AnyIO</a>를 기반으로 하고있고, 따라서 파이썬 표준 라이브러리인 <a href="https://docs.python.org/3/library/asyncio-task.html" class="external-link" target="_blank">asyncio</a> 및 <a href="https://trio.readthedocs.io/en/stable/" class="external-link" target="_blank">Trio</a>와 호환됩니다.

  }

  private abstract static class AtomicHelper {
    /** Performs an atomic compare-and-set of {@link AggregateFutureState#seenExceptionsField}. */
    abstract void compareAndSetSeenExceptions(
        AggregateFutureState<?> state, @Nullable Set<Throwable> expect, Set<Throwable> update);

    /** Performs an atomic decrement-and-get of {@link AggregateFutureState#remainingField}. */

If you have an older version, you would get errors when trying to use `Annotated`.

Make sure you [Upgrade the FastAPI version](../deployment/versions.md#upgrading-the-fastapi-versions){.internal-link target=_blank} to at least 0.95.1 before using `Annotated`.

///

## Declare metadata { #declare-metadata }

You can declare all the same parameters as for `Query`.

---

## Instalar FastAPI { #install-fastapi }

El primer paso es instalar FastAPI.

Asegúrate de crear un [entorno virtual](../virtual-environments.md){.internal-link target=_blank}, actívalo, y luego **instala FastAPI**:

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

/// note | Nota

import java.util.Iterator;
import java.util.LinkedList;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Synchronized#deque} and {@link Queues#synchronizedDeque}.
 *
 * @author Kurt Alfred Kluever
 */
@NullUnmarked
public class SynchronizedDequeTest extends TestCase {

  protected Deque<String> create() {

			logger.Startup(color.Blue("   RootPass: ") + color.Bold("%s ", cred.SecretKey))
		}
	}

	printEventNotifiers()
	printLambdaTargets()
}

// Prints startup message for Object API access, prints link to our SDK documentation.
func printObjectAPIMsg() {
	logger.Startup(color.Blue("\nDocs: ") + "https://docs.min.io")
}

func printLambdaTargets() {

package jcifs;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;

import org.junit.jupiter.api.Test;

/**
 * Tests for the {@link ResolverType} enum.
 * This class ensures that the enum constants are defined as expected.
 */
class ResolverTypeTest {

    /**
     * Tests that all expected enum constants exist.
     */
    @Test
    void testEnumConstants() {

import org.apache.maven.api.annotations.Nonnull;

/**
 * A version or meta-version of an artifact or a dependency.
 * A meta-version is a version suffixed with the {@code SNAPSHOT} keyword.
 * Versions are usually parsed using the {@link org.apache.maven.api.services.VersionParser} service.
 *
 * @since 4.0.0
 * @see org.apache.maven.api.services.VersionParser#parseVersion(String)
 * @see org.apache.maven.api.Session#parseVersion(String)

# 请求表单与文件

FastAPI 支持同时使用 `File` 和 `Form` 定义文件和表单字段。

/// info | 说明

接收上传文件或表单数据，要预先安装 <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>。

例如，`pip install python-multipart`。

///

## 导入 `File` 与 `Form`

{* ../../docs_src/request_forms_and_files/tutorial001.py hl[1] *}

## 定义 `File` 与 `Form` 参数

创建文件和表单参数的方式与 `Body` 和 `Query` 一样：