Dann, mit einer URL wie:

```
http://localhost:8000/items/?q=foo&q=bar
```

bekommen Sie alle `q`-*Query-Parameter*-Werte (`foo` und `bar`) in einer Python-Liste – `list` – in ihrer *Pfadoperation-Funktion*, im Funktionsparameter `q`, überreicht.

Die Response für diese URL wäre also:

```JSON
{
  "q": [
    "foo",
    "bar"
  ]
}
```

/// tip | "Tipp"

   *
   * <p>For example, if {@code rangeMap} had the entries {@code [1, 5] => "foo", (6, 8) => "bar",
   * (10, ∞) => "baz"} then {@code rangeMap.subRangeMap(Range.open(3, 12))} would return a range map
   * with the entries {@code (3, 5] => "foo", (6, 8) => "bar", (10, 12) => "baz"}.
   *
   * <p>The returned range map supports all optional operations that this range map supports, except

        return dr;
    }


    /*
     * Split DFS path like \fs1.example.com\root5\link2\foo\bar.txt into at
     * most 3 components (not including the first index which is always empty):
     * result[0] = ""
     * result[1] = "fs1.example.com"
     * result[2] = "root5"
     * result[3] = "link2\foo\bar.txt"
     */
    private static int dfsPathSplit ( String path, String[] result ) {

🚥 👩‍💻 📨 `http://example.com/items/foo` ( `item_id` `"foo"`), 👈 👩‍💻 🔜 📨 🇺🇸🔍 👔 📟 2️⃣0️⃣0️⃣, & 🎻 📨:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

✋️ 🚥 👩‍💻 📨 `http://example.com/items/bar` (🚫-🚫 `item_id` `"bar"`), 👈 👩‍💻 🔜 📨 🇺🇸🔍 👔 📟 4️⃣0️⃣4️⃣ ("🚫 🔎" ❌), & 🎻 📨:

```JSON
{
  "detail": "Item not found"
}
```

/// tip

```JSON
{
  "item": "The Foo Wrestlers"
}
```

Aber wenn der Client `http://example.com/items/bar` anfragt (ein nicht-existierendes `item_id` `"bar"`), erhält er einen HTTP-Statuscode 404 (der „Not Found“-Fehler), und eine JSON-Response wie folgt:

```JSON
{
  "detail": "Item not found"
}
```

/// tip | "Tipp"

  public void testControlsArraySize() {
    ImmutableSet.Builder<String> builder = new ImmutableSet.Builder<String>();
    for (int i = 0; i < 10; i++) {
      builder.add("foo");
    }
    builder.add("bar");
    RegularImmutableSet<String> set = (RegularImmutableSet<String>) builder.build();
    assertTrue(set.elements.length <= 2 * set.size());
  }

  @GwtIncompatible("internals")
  public void testReusedBuilder() {

```

本例中，**FastAPI** 不使用 `__init__`，我们要直接在代码中使用。

## 创建实例

使用以下代码创建类实例：

```Python hl_lines="16"
{!../../docs_src/dependencies/tutorial011.py!}
```

这样就可以**参数化**依赖项，它包含 `checker.fixed_content` 的属性 - `"bar"`。

## 把实例作为依赖项

然后，不要再在 `Depends(checker)` 中使用 `Depends(FixedContentQueryChecker)`， 而是要使用 `checker`，因为依赖项是类实例 - `checker`，不是类。

处理依赖项时，**FastAPI** 以如下方式调用 `checker`：

```Python
checker(q="somequery")
```

     * <tr>
     * <td>{@literal foo}</td>
     * <td>{@literal foo}</td>
     * </tr>
     * <tr>
     * <td>{@literal foo_bar}</td>
     * <td>{@literal foo.bar}</td>
     * </tr>
     * <tr>
     * <td>{@literal foo_bar_baz}</td>
     * <td>{@literal foo.bar.baz}</td>
     * </tr>
     * </table>
     *
     * @param beanDelimiter
     *            JavaBeansのデリミタ
     * @return このインスタンス自身
     */

## Create an instance

We could create an instance of this class with:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

And that way we are able to "parameterize" our dependency, that now has `"bar"` inside of it, as the attribute `checker.fixed_content`.

## Use the instance as a dependency

    mockWebServer: MockWebServer,
  ) {
    setUp(protocol, mockWebServer)
    val pushPromise =
      PushPromise(
        "GET",
        "/foo/bar",
        headersOf("foo", "bar"),
        MockResponse(body = "bar"),
      )
    server.enqueue(
      MockResponse.Builder()
        .body("ABCDE")
        .addPush(pushPromise)
        .build(),
    )