items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):
    return items[item_id]


def test_read_items():
    with TestClient(app) as client:
        response = client.get("/items/foo")
        assert response.status_code == 200

    message: str


app = FastAPI()


@app.get("/items/{item_id}", response_model=Item, responses={404: {"model": Message}})
async def read_item(item_id: str):
    if item_id == "foo":
        return {"id": "foo", "value": "there goes my hero"}

    Iterator<String> unfiltered = Lists.newArrayList("foo", "bar").iterator();
    Iterator<String> filtered = filter(unfiltered, equalTo("foo"));
    List<String> expected = singletonList("foo");
    List<String> actual = Lists.newArrayList(filtered);
    assertEquals(expected, actual);
  }

  public void testFilterNoMatch() {
    Iterator<String> unfiltered = Lists.newArrayList("foo", "bar").iterator();

    assertThat(findClassesToTest(ImmutableList.of(Foo.class))).containsExactly(Foo.class);
    assertThat(findClassesToTest(ImmutableList.of(Foo.class, Foo2Test.class)))
        .containsExactly(Foo.class);
  }

  public void testFindClassesToTest_publicApiOnly() {
    sanityTests.publicApiOnly();
    assertThat(findClassesToTest(ImmutableList.of(Foo.class))).isEmpty();

The value of the path parameter `item_id` will be passed to your function as the argument `item_id`.

So, if you run this example and go to [http://127.0.0.1:8000/items/foo](http://127.0.0.1:8000/items/foo), you will see a response of:

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

## Path parameters with types { #path-parameters-with-types }

You can declare the type of a path parameter in the function, using standard Python type annotations:

from typing import Annotated

from fastapi import FastAPI, Header, HTTPException
from pydantic import BaseModel

fake_secret_token = "coneofsilence"

fake_db = {
    "foo": {"id": "foo", "title": "Foo", "description": "There goes my hero"},
    "bar": {"id": "bar", "title": "Bar", "description": "The bartenders"},
}

app = FastAPI()


class Item(BaseModel):
    id: str
    title: str
    description: str | None = None

    }

    /**
     * Replaces all the values of a given key/value pairs for all project REST tests.
     * For example "foo": "bar" can replaced as "foo": "baz"
     *
     * @param key      the key to find
     * @param oldValue the value of that key to find
     * @param newValue the value used in the replacement
     */

 *
 * {@snippet :
 * Splitter.on(',').split("foo,bar,qux")
 * }
 *
 * ... 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:
 *
 * {@snippet :
 * Splitter.on(',').split(" foo,,,  bar ,")
 * }
 *

通过浏览器访问 [http://127.0.0.1:8000/items/foo](http://127.0.0.1:8000/items/foo)，接收如下 HTTP 错误信息：

```JSON
{
  "detail": [
    {
      "type": "int_parsing",
      "loc": [
        "path",
        "item_id"
      ],
      "msg": "Input should be a valid integer, unable to parse string as an integer",
      "input": "foo"
    }
  ]
}
```

这是因为路径参数 `item_id` 的值（`"foo"`）的类型不是 `int`。

            }

            dependencies {
                testImplementation 'junit:junit:4.12'
            }

            tasks.named('test').configure {
                nonInputProperties.systemProperty("foo", project.getProperty('foo'))
            }
        """

        when:
        def result = gradleRunner("test", '-Dtests.seed=default', '-Pfoo=bar').build()

        then: