[
        ("/items", None, 200, {"strange_header": None}),
        ("/items", {"X-Header": "notvalid"}, 200, {"strange_header": None}),
        (
            "/items",
            {"strange_header": "FastAPI test"},
            200,
            {"strange_header": "FastAPI test"},
        ),
        (
            "/items",
            {"strange-header": "Not really underscore"},

        "paths": {
            "/items/{item_id}": {
                "put": {
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "integer"},

        "paths": {
            "/items/{item_id}": {
                "put": {
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "integer"},

        "paths": {
            "/items/{item_id}": {
                "put": {
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "integer"},

def test_websocket():
    with client.websocket_connect("/items/portal-gun") as websocket:
        data = websocket.receive_json()
        assert data == {"item_id": "portal-gun", "path": "/items/{item_id}"}


def test_websocket_invalid_path_doesnt_match():
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/itemsx/portal-gun"):

client = TestClient(app)


def test_get_no_item():
    response = client.get("/items/foo")
    assert response.status_code == 404, response.text
    assert response.json() == {"detail": "Item not found"}


def test_owner_error():
    response = client.get("/items/plumbus")
    assert response.status_code == 400, response.text
    assert response.json() == {"detail": "Owner error: Rick"}

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Annotated[
        str | None,
        Query(
            title="Query string",
            description="Query string for the items to search in the database that have a good match",
            min_length=3,
        ),
    ] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:

    String simple = "a,b,c,d";
    Iterable<String> items = COMMA_SPLITTER.limit(1).split(simple);
    assertThat(items).containsExactly("a,b,c,d").inOrder();
  }

  public void testLimitSeparator() {
    String simple = "a,b,c,d";
    Iterable<String> items = COMMA_SPLITTER.limit(2).split(simple);
    assertThat(items).containsExactly("a", "b,c,d").inOrder();
  }

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

💲 ➡ 🔢 `item_id` 🔜 🚶‍♀️ 👆 🔢 ❌ `item_id`.

, 🚥 👆 🏃 👉 🖼 &amp; 🚶 <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, 👆 🔜 👀 📨:

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

## ➡ 🔢 ⏮️ 🆎

👆 💪 📣 🆎 ➡ 🔢 🔢, ⚙️ 🐩 🐍 🆎 ✍:

```Python hl_lines="7"

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/", tags=["items"])
async def read_items():
    return [{"name": "Foo", "price": 42}]


@app.get("/users/", tags=["users"])
async def read_users():
    return [{"username": "johndoe"}]


@app.get("/elements/", tags=["items"], deprecated=True)
async def read_elements():