## 混合使用 `Path`、`Query` 和请求体参数

首先，毫无疑问地，你可以随意地混合使用 `Path`、`Query` 和请求体参数声明，**FastAPI** 会知道该如何处理。

你还可以通过将默认值设置为 `None` 来将请求体参数声明为可选参数：

{* ../../docs_src/body_multiple_params/tutorial001_an_py310.py hl[18:20] *}

/// note

请注意，在这种情况下，将从请求体获取的 `item` 是可选的。因为它的默认值为 `None`。

///

## 多个请求体参数

在上面的示例中，*路径操作*将期望一个具有 `Item` 的属性的 JSON 请求体，就像：

```JSON
{
    "name": "Foo",

    void testInitDefaultsSetsAllFields() throws CIFSException {
        BaseConfiguration testConfig = new BaseConfiguration(false);
        testConfig.initDefaults();

        // Check random and time zone
        assertNotNull(testConfig.getRandom());
        assertNotNull(testConfig.getLocalTimezone());

        // Check PID is set
        assertTrue(testConfig.getPid() >= 0);

print(f"Hello {name} from Python")
```

/// tip

第二个参数是 <a href="https://docs.python.org/zh-cn/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 的默认返回值。

如果没有提供，默认值为 `None`，这里我们提供 `"World"` 作为默认值。

///

然后你可以调用这个 Python 程序：

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

<div class="termy">

```console
// 这里我们还没有设置环境变量
$ python main.py

// 因为我们没有设置环境变量，所以我们得到的是默认值

			return Config{}, err
		}
	} else {
		cfg.RRS.Parity = defaultRRSParity
		if setDriveCount == 1 {
			cfg.RRS.Parity = 0
		}
	}

	// Validation is done after parsing both the storage classes. This is needed because we need one
	// storage class value to deduce the correct value of the other storage class.
	if err = validateParity(cfg.Standard.Parity, cfg.RRS.Parity, setDriveCount); err != nil {
		return Config{}, err

        response = client.get("/items/foo")
        assert response.status_code == 200
        assert response.json() == {"name": "Fighters"}

        # After the requests is done, the items are still there
        assert items == {"foo": {"name": "Fighters"}, "bar": {"name": "Tenders"}}

    # The end of the "with TestClient" block simulates terminating the app, so

That means that any value read in Python from an environment variable will be a `str`, and any conversion to a different type or any validation has to be done in code.

## Pydantic `Settings` { #pydantic-settings }

 * java.util.concurrent}, {@code java.util.regex}, {@code com.google.common.base}, {@code
 * com.google.common.collect} and {@code com.google.common.primitives}. In addition, if the type
 * exposes at least one public static final constant of the same type, one of the constants will be
 * used; or if the class exposes a public parameter-less constructor then it will be "new"d and
 * returned.
 *

 * @author mbechler
 *
 * <p>This interface is intended for internal use.</p>
 */
public interface BufferCache {

    /**
     * Gets a buffer from the cache or creates a new one if the cache is empty.
     *
     * @return a buffer from the cache, or a new one
     */
    byte[] getBuffer();

    /**
     * Return a buffer to the cache
     *
     * @param buf the buffer to return to the cache for reuse
     */

import subprocess
import time

import httpx
from playwright.sync_api import Playwright, sync_playwright


# Run playwright codegen to generate the code below, copy paste the sections in run()
def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    # Update the viewport manually
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    browser = playwright.chromium.launch(headless=False)

## URLs da Documentação { #docs-urls }

Você pode configurar as duas interfaces de documentação incluídas:

* **Swagger UI**: acessível em `/docs`.
    * Você pode definir sua URL com o parâmetro `docs_url`.
    * Você pode desativá-la definindo `docs_url=None`.
* **ReDoc**: acessível em `/redoc`.