public void testNullIsPassedThrough() {
    Converter<String, String> nullsArePassed = sillyConverter(false);
    assertEquals("forward", nullsArePassed.convert("foo"));
    assertEquals("forward", nullsArePassed.convert(null));
    assertEquals("backward", nullsArePassed.reverse().convert("foo"));
    assertEquals("backward", nullsArePassed.reverse().convert(null));
  }

  public void testNullIsNotPassedThrough() {

@app.get("/items/coerce", response_model=Item)
def get_coerce():
    return {"name": "coerce", "price": "1.0"}


@app.get("/items/validlist", response_model=List[Item])
def get_validlist():
    return [
        {"name": "foo"},
        {"name": "bar", "price": 1.0},
        {"name": "baz", "price": 2.0, "owner_ids": [1, 2, 3]},
    ]


client = TestClient(app)


def test_valid():
    response = client.get("/items/valid")

```Python hl_lines="6-7"
{!../../docs_src/path_params/tutorial001.py!}
```

这段代码把路径参数 `item_id` 的值传递给路径函数的参数 `item_id`。

运行示例并访问 <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>，可获得如下响应：

```JSON
{"item_id":"foo"}
```

## 声明路径参数的类型

使用 Python 标准类型注解，声明路径操作函数中路径参数的类型。

```Python hl_lines="7"
{!../../docs_src/path_params/tutorial002.py!}
```

 *
 * <pre>{@code
 * Splitter.on(',').split("foo,bar,qux")
 * }</pre>
 *
 * ... produces an {@code Iterable} containing {@code "foo"}, {@code "bar"} and {@code "qux"}, in
 * that order.
 *
 * <p>By default, {@code Splitter}'s behavior is simplistic and unassuming. The following
 * expression:
 *
 * <pre>{@code
 * Splitter.on(',').split(" foo,,,  bar ,")
 * }</pre>
 *

client = TestClient(app)


def test_default_query_values():
    url = "/items/"
    response = client.get(url)
    assert response.status_code == 200, response.text
    assert response.json() == {"q": ["foo", "bar"]}


def test_multi_query_values():
    url = "/items/?q=baz&q=foobar"
    response = client.get(url)
    assert response.status_code == 200, response.text
    assert response.json() == {"q": ["baz", "foobar"]}

from docs_src.query_params_str_validations.tutorial013_an import app

client = TestClient(app)


def test_multi_query_values():
    url = "/items/?q=foo&q=bar"
    response = client.get(url)
    assert response.status_code == 200, response.text
    assert response.json() == {"q": ["foo", "bar"]}


def test_query_no_values():
    url = "/items/"
    response = client.get(url)
    assert response.status_code == 200, response.text

    client = TestClient(app)
    return client


@needs_py39
def test_multi_query_values(client: TestClient):
    url = "/items/?q=foo&q=bar"
    response = client.get(url)
    assert response.status_code == 200, response.text
    assert response.json() == {"q": ["foo", "bar"]}


@needs_py39
def test_query_no_values(client: TestClient):
    url = "/items/"
    response = client.get(url)

 * token68:
 *
 * ```
 * WWW-Authenticate: Digest foo=bar
 * WWW-Authenticate: Digest foo=
 * ```
 *
 * Similarly, the first line has one challenge and the second line has two challenges:
 *
 * ```
 * WWW-Authenticate: Digest ,foo=bar
 * WWW-Authenticate: Digest ,foo
 * ```
 */
fun Headers.parseChallenges(headerName: String): List<Challenge> {

KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
-->

<project>
  <modelVersion>4.0.0</modelVersion>
  <artifactId>foo</artifactId>
  <groupId>foo</groupId>
  <version>99.44</version>
  <packaging>bleh</packaging>
  <build>
    <resources>
      <resource>

      </resource>
    </resources>
    <testResources>
      <testResource>

  }

  @Override
  protected Map<String, Map<Integer, Character>> makePopulatedMap() {
    Table<Integer, String, Character> table = HashBasedTable.create();
    table.put(1, "foo", 'a');
    table.put(1, "bar", 'b');
    table.put(3, "foo", 'c');
    return unmodifiableTable(table).columnMap();
  }