And also after the `response` is generated, before returning it.

For example, you could add a custom header `X-Process-Time` containing the time in seconds that it took to process the request and generate a response:

```Python hl_lines="10  12-13"
{!../../../docs_src/middleware/tutorial001.py!}
```

## Other middlewares

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

!!! info
    `**second_user_data` bedeutet:

对于这些情况，你可以使用Python的技术，将 `dict` 与 `**dict_to_unpack` 解包：
```Python
old_dict = {
    "old key": "old value",
    "second old key": "second old value",
}
new_dict = {**old_dict, "new key": "new value"}
```

这里， new_dict 将包含来自 old_dict 的所有键值对加上新的键值对：
```python
{
    "old key": "old value",
    "second old key": "second old value",
    "new key": "new value",
}
```
您可以使用该技术在路径操作中重用一些预定义的响应，并将它们与其他自定义响应相结合。
**例如：**

```

これは以下のように用いられます:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

!!! info "情報"
    `**second_user_data` は以下を意味します：

    `second_user_data`辞書のキーと値を直接、キーと値の引数として渡します。これは、`User(id=4, name="Mary", joined="2018-11-30")`と同等です。

### エディタのサポート

```Python
from app.routers import items, users
```

!!! info
    The first version is a "relative import":

    ```Python
    from .routers import items, users
    ```

    The second version is an "absolute import":

    ```Python
    from app.routers import items, users
    ```

#### Dict

To define a `dict`, you pass 2 type parameters, separated by commas.

The first type parameter is for the keys of the `dict`.

The second type parameter is for the values of the `dict`:

=== "Python 3.9+"

    ```Python hl_lines="1"
    {!> ../../../docs_src/python_types/tutorial008_py39.py!}
    ```

=== "Python 3.8+"

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

!!! info
    `**second_user_data` means:

    Pass the keys and values of the `second_user_data` dict directly as key-value arguments, equivalent to: `User(id=4, name="Mary", joined="2018-11-30")`

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

!!! info
    `**second_user_data` quer dizer:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

!!! info
    `**second_user_data` signifie:

```

可以像这样来使用：

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```


!!! info
    `**second_user_data` 意思是:

    直接将`second_user_data`字典的键和值直接作为key-value参数传递，等同于：`User(id=4, name="Mary", joined="2018-11-30")`

### 编辑器支持