* 类型为 `int` 的可选查询参数 `limit`，默认值是 `100`

然后，依赖项函数返回包含这些值的 `dict`。

### 导入 `Depends`

```Python hl_lines="3"
{!../../../docs_src/dependencies/tutorial001.py!}
```

### 声明依赖项

与在*路径操作函数*参数中使用 `Body`、`Query` 的方式相同，声明依赖项需要使用 `Depends` 和一个新的参数：

```Python hl_lines="15  20"
{!../../../docs_src/dependencies/tutorial001.py!}
```

虽然，在路径操作函数的参数中使用 `Depends` 的方式与 `Body`、`Query` 相同，但 `Depends` 的工作方式略有不同。

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Oppure usa <code>async def</code>...</summary>

Se il tuo codice usa `async` / `await`, allora usa `async def`:

```Python hl_lines="7  12"
from fastapi import FastAPI
from typing import Optional

app = FastAPI()


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


@app.get("/items/{item_id}")

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Albo użyj <code>async def</code>...</summary>

Jeżeli twój kod korzysta z `async` / `await`, użyj `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")

```

<details markdown="1">
<summary>Или используйте <code>async def</code>...</summary>

Если ваш код использует `async` / `await`, используйте `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>或者使用 <code>async def</code>...</summary>

如果你的代码里会出现 `async` / `await`，请使用 `async def`：

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")

=== "Python 3.10+"

    ```Python hl_lines="8-9"
    {!> ../../../docs_src/dependencies/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="8-11"
    {!> ../../../docs_src/dependencies/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="9-12"
    {!> ../../../docs_src/dependencies/tutorial001_an.py!}
    ```

=== "Python 3.10+"

    ```Python hl_lines="8-9"
    {!> ../../../docs_src/dependencies/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="8-11"
    {!> ../../../docs_src/dependencies/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="9-12"
    {!> ../../../docs_src/dependencies/tutorial001_an.py!}
    ```

* オプショナルのクエリパラメータ`limit`は`int`で、デフォルトは`100`です。

そして、これらの値を含む`dict`を返します。

### `Depends`のインポート

```Python hl_lines="3"
{!../../../docs_src/dependencies/tutorial001.py!}
```

### "dependant"での依存関係の宣言

*path operation関数*のパラメータに`Body`や`Query`などを使用するのと同じように、新しいパラメータに`Depends`を使用することができます:

```Python hl_lines="13  18"
{!../../../docs_src/dependencies/tutorial001.py!}
```

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Vagy használd az <code>async def</code>-et...</summary>

Ha a kódod `async` / `await`-et, használ `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>O usa <code>async def</code>...</summary>

Si tu código usa `async` / `await`, usa `async def`:

```Python hl_lines="7  12"
from fastapi import FastAPI
from typing import Union

app = FastAPI()


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


@app.get("/items/{item_id}")