```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!}
```

# Test required and embedded body parameters with no bodies sent
@needs_py310
def test_post_body_example(client: TestClient):
    response = client.put(
        "/items/5",
        json={
            "name": "Foo",
            "description": "A very nice Item",
            "price": 35.4,
            "tax": 3.2,
        },
    )
    assert response.status_code == 200


@needs_py310

@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")

    assert response.json() == {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}


def test_query_params_str_validations_item_query_fixedquery(client: TestClient):
    response = client.get("/items/", params={"item-query": "fixedquery"})
    assert response.status_code == 200
    assert response.json() == {
        "items": [{"item_id": "Foo"}, {"item_id": "Bar"}],
        "q": "fixedquery",
    }

Donc, si vous exécutez cet exemple et allez sur <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>,
vous verrez comme réponse :

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

## Paramètres de chemin typés

client = TestClient(app)


@pytest.mark.parametrize(
    "path,expected_status,expected_response",
    [
        ("/items/", 200, [{"name": "Foo", "price": 42}]),
        ("/users/", 200, [{"username": "johndoe"}]),
        ("/elements/", 200, [{"item_id": "Foo"}]),
    ],
)
def test_query_params_str_validations(path, expected_status, expected_response):
    response = client.get(path)

Ce qui fait qu'avec une URL comme :

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

vous recevriez les valeurs des multiples paramètres de requête `q` (`foo` et `bar`) dans une `list` Python au sein de votre fonction de **path operation**, dans le paramètre de fonction `q`.

Donc la réponse de cette URL serait :

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

!!! tip "Astuce"

                },
            ]
        }
    )


def test_users_foo_token_jessica(client: TestClient):
    response = client.get("/users/foo?token=jessica")
    assert response.status_code == 200
    assert response.json() == {"username": "foo"}


def test_users_foo_with_no_token(client: TestClient):
    response = client.get("/users/foo")
    assert response.status_code == 422
    assert response.json() == IsDict(

            ]
        }
    )


@needs_py39
def test_users_foo_token_jessica(client: TestClient):
    response = client.get("/users/foo?token=jessica")
    assert response.status_code == 200
    assert response.json() == {"username": "foo"}


@needs_py39
def test_users_foo_with_no_token(client: TestClient):
    response = client.get("/users/foo")
    assert response.status_code == 422
    assert response.json() == IsDict(

    client = TestClient(app)
    return client


@needs_py310
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_py310
def test_query_no_values(client: TestClient):
    url = "/items/"
    response = client.get(url)