from fastapi import FastAPI, Path
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    item_id: Annotated[int, Path(title="The ID of the item to get")], q: str
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, Path

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    *,
    item_id: int = Path(title="The ID of the item to get", gt=0, le=1000),
    q: str,
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

Ele também declara novamente `id: int`. Ao fazer isso, estamos fazendo um **contrato** com os clientes da API, para que eles possam sempre esperar que o `id` estará lá e será um `int` (nunca será `None`).

/// tip | Dica

            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]
}
```

これは、パスパラメータ `item_id` が `int` ではない値 `"foo"` だからです。

<a href="http://127.0.0.1:8000/items/4.2" class="external-link" target="_blank">http://127.0.0.1:8000/items/4.2</a> で見られるように、intのかわりに `float` が与えられた場合にも同様なエラーが表示されます。

/// check | "確認"

したがって、Pythonの型宣言を使用することで、**FastAPI**はデータのバリデーションを行います。

        }

        key = key.toLowerCase(Locale.ROOT);

        Iterator<String> iter = refs.map.keySet().iterator();
        int searchLen = key.length();
        while ( iter.hasNext() ) {
            String cachedKey = iter.next();
            int cachedKeyLen = cachedKey.length();

            boolean match = false;
            if ( cachedKeyLen == searchLen ) {

from typing import Annotated

from fastapi import FastAPI, Path

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    q: str, item_id: Annotated[int, Path(title="The ID of the item to get")]
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

from typing import Annotated

from fastapi import FastAPI, Path

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    item_id: Annotated[int, Path(title="The ID of the item to get")], q: str
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

from typing import Annotated

from fastapi import FastAPI, Path

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    item_id: Annotated[int, Path(title="The ID of the item to get", ge=1)], q: str
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

    try {
      multiset.add(sampleElement, 2);
      fail("add(Object, int) succeeded on unmodifiable collection");
    } catch (UnsupportedOperationException expected) {
    }
    assertCollectionsAreEquivalent(multiset, copy);

    try {
      multiset.remove(sampleElement, 2);
      fail("remove(Object, int) succeeded on unmodifiable collection");
    } catch (UnsupportedOperationException expected) {
    }