访问 URL：

```
http://127.0.0.1:8000/items/
```

与访问以下地址相同：

```
http://127.0.0.1:8000/items/?skip=0&limit=10
```

但如果访问：

```
http://127.0.0.1:8000/items/?skip=20
```

查询参数的值就是：

* `skip=20`：在 URL 中设定的值
* `limit=10`：使用默认值

## 可选参数

同理，把默认值设为 `None` 即可声明**可选的**查询参数：

=== "Python 3.10+"

    ```Python hl_lines="7"

  public void testAutoIncrementStep_nanos() {
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(10, TimeUnit.NANOSECONDS);
    assertEquals(0, ticker.read());
    assertEquals(10, ticker.read());
    assertEquals(20, ticker.read());
  }

  public void testAutoIncrementStep_millis() {
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(1, TimeUnit.MILLISECONDS);
    assertEquals(0, ticker.read());

    LinkedHashMultimap<String, Integer> multimap = LinkedHashMultimap.create(20, 15);
    multimap.put("foo", 1);
    multimap.put("bar", 2);
    multimap.put("foo", 3);
    assertEquals(ImmutableSet.of(1, 3), multimap.get("foo"));
  }

  public void testCreateFromIllegalSizes() {
    try {
      LinkedHashMultimap.create(-20, 15);
      fail();
    } catch (IllegalArgumentException expected) {
    }

                TestCoverage(4, TestType.platform, Os.WINDOWS, JvmCategory.MAX_VERSION),
                TestCoverage(20, TestType.configCache, Os.LINUX, JvmCategory.MIN_VERSION, DEFAULT_LINUX_FUNCTIONAL_TEST_BUCKET_SIZE)
            ),
            docsTests = listOf(

import org.codelibs.fess.util.ComponentUtil;

public class ElevateWordPager implements Serializable {

    private static final long serialVersionUID = 1L;

    public static final int DEFAULT_PAGE_SIZE = 20;

    public static final int DEFAULT_CURRENT_PAGE_NUMBER = 1;

    private int allRecordCount;

    private int allPageCount;

    private boolean existPrePage;

    private boolean existNextPage;

import org.codelibs.fess.util.ComponentUtil;

public class LabelTypePager implements Serializable {

    private static final long serialVersionUID = 1L;

    public static final int DEFAULT_PAGE_SIZE = 20;

    public static final int DEFAULT_CURRENT_PAGE_NUMBER = 1;

    private int allRecordCount;

    private int allPageCount;

    private boolean existPrePage;

    private boolean existNextPage;

    run:
      - action: add-label@v1
        # etr is defined in the last section of this example
        args:
          label: "{{ calc.etr }} min review"
          color: {{ 'E94637' if (calc.etr >= 20) else ('FBBD10' if (calc.etr >= 5) else '36A853') }}

# To simplify the automations section, some calculations are placed under unique YAML keys defined here.

        return new VersionsMetadataGenerator(session, request);
    }

    @SuppressWarnings("checkstyle:magicnumber")
    @Override
    public float getPriority() {
        return 20; // GA level metadata should be deployed 2nd MD
    }

    {!> ../../../docs_src/body_nested_models/tutorial004_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="20"
    {!> ../../../docs_src/body_nested_models/tutorial004_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="20"
    {!> ../../../docs_src/body_nested_models/tutorial004.py!}
    ```

This would mean that **FastAPI** would expect a body similar to:

    "price": 42.0,
    "tax": 3.2
}
```

Mas você pode também declarar múltiplos parâmetros de corpo, por exemplo, `item` e `user`:

=== "Python 3.10+"

    ```Python hl_lines="20"
    {!> ../../../docs_src/body_multiple_params/tutorial002_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="22"
    {!> ../../../docs_src/body_multiple_params/tutorial002.py!}
    ```