O valor do parâmetro de path `item_id` será passado para a sua função como o argumento `item_id`.

Então, se você executar este exemplo e acessar <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, você verá uma resposta:

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

## Parâmetros de path com tipos { #path-parameters-with-types }

比如，下面有 4 个 API 路径操作（*端点*）：

* `/items/public/`
* `/items/private/`
* `/users/{user_id}/activate`
* `/items/pro/`

开发人员可以使用依赖项及其子依赖项为这些路径操作添加不同的权限：

```mermaid
graph TB

current_user(["current_user"])
active_user(["active_user"])
admin_user(["admin_user"])
paying_user(["paying_user"])

public["/items/public/"]
private["/items/private/"]
activate_user["/users/{user_id}/activate"]

    return client


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"]}


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

### 動作確認

ブラウザから<a href="http://127.0.0.1:8000/items/5?q=somequery" class="external-link" target="_blank">http://127.0.0.1:8000/items/5?q=somequery</a>を開きます。

以下の JSON のレスポンスが確認できます:

```JSON
{"item_id": 5, "q": "somequery"}
```

もうすでに以下の API が作成されています:

- `/` と `/items/{item_id}`のパスで HTTP リクエストを受けます。
- どちらのパスも `GET` 操作 を取ります。(HTTP メソッドとしても知られています。)
- `/items/{item_id}` パスのパスパラメータ `item_id` は `int` でなければなりません。

    return client


def test_get_random_item(client: TestClient):
    response = client.get("/items")
    assert response.status_code == 200, response.text
    assert response.json() == {"id": IsStr(), "name": IsStr()}


def test_get_item(client: TestClient):
    response = client.get("/items?id=isbn-9781529046137")
    assert response.status_code == 200, response.text
    assert response.json() == {

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = Query(min_length=3)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

            new_value = []
            for item in value:
                if isinstance(item, dict):
                    new_item = _replace_refs(
                        schema=item,
                        old_name_to_new_name_map=old_name_to_new_name_map,
                    )
                    new_value.append(new_item)

                else:
                    new_value.append(item)
            new_schema[key] = new_value

from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(q: Union[str, None] = None):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str, Query(min_length=3)] = "fixedquery"):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from typing import Union

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Union[str, None] = Query(min_length=3)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})