raise


@app.get("/items/{item_id}")
def get_item(item_id: str, username: str = Depends(get_username)):
    if item_id == "portal-gun":
        raise InternalError(
            f"The portal gun is too dangerous to be owned by {username}"
        )
    if item_id != "plumbus":
        raise HTTPException(

        raise


@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):
    if item_id == "portal-gun":
        raise InternalError(
            f"The portal gun is too dangerous to be owned by {username}"
        )
    if item_id != "plumbus":
        raise HTTPException(

        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/{item_id}": {
                "put": {
                    "parameters": [
                        {
                            "in": "path",
                            "name": "item_id",
                            "required": True,
                            "schema": {

    return await request_validation_exception_handler(request, exc)


@app.get("/items/{item_id}")
async def read_item(item_id: int):
    if item_id == 3:
        raise HTTPException(status_code=418, detail="Nope! I don't like 3.")

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/{item_id}")
async def read_item(item_id):

from fastapi import FastAPI, Request

app = FastAPI()


@app.get("/items/{item_id}")
def read_root(item_id: str, request: Request):
    client_host = request.client.host

    return item


@app.get("/path_examples/{item_id}")
def path_examples(
    item_id: str = Path(
        examples=[
            "json_schema_item_1",
            "json_schema_item_2",
        ],
        openapi_examples={
            "Path One": {
                "summary": "Path One Summary",
                "description": "Path One Description",
                "value": "item_1",
            },
            "Path Two": {

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。

{* ../../docs_src/path_params/tutorial002.py hl[7] *}

本例把 `item_id` 的类型声明为 `int`。

/// check | 检查

{* ../../docs_src/path_params/tutorial001_py39.py hl[6:7] *}

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 }

    assert response.status_code == 200
    assert response.json() == {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}


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


def test_query_params_str_validations_q_query(client: TestClient):