)
def get_exclude_unset() -> ModelDefaults:
    return ModelDefaults(x=None, y="y")


@app.get(
    "/exclude_defaults",
    response_model=ModelDefaults,
    response_model_exclude_defaults=True,
)
def get_exclude_defaults() -> ModelDefaults:
    return ModelDefaults(x=None, y="y")


@app.get(
    "/exclude_none", response_model=ModelDefaults, response_model_exclude_none=True
)

                }
            },
            "/level1/level2/default5": {
                "get": {
                    "tags": ["level1a", "level1b", "level2a", "level2b"],
                    "summary": "Path5 Default Router4 Default",
                    "operationId": "path5_default_router4_default_level1_level2_default5_get",
                    "parameters": [
                        {

* `tax: float = 10.5` has a default of `10.5`.
* `tags: List[str] = []` has a default of an empty list: `[]`.

but you might want to omit them from the result if they were not actually stored.

For example, if you have models with many optional attributes in a NoSQL database, but you don't want to send very long JSON responses full of default values.

```Python hl_lines="2  6"
{!../../../docs_src/advanced_middleware/tutorial003.py!}
```

The following arguments are supported:

* `minimum_size` - Do not GZip responses that are smaller than this minimum size in bytes. Defaults to `500`.

## Other middlewares

There are many other ASGI middlewares.

For example:

* <a href="https://docs.sentry.io/platforms/python/guides/fastapi/" class="external-link" target="_blank">Sentry</a>

!!! info
    你还可以使用：

    * `response_model_exclude_defaults=True`
    * `response_model_exclude_none=True`

    参考 <a href="https://docs.pydantic.dev/latest/concepts/serialization/#modeldict" class="external-link" target="_blank">Pydantic 文档</a> 中对 `exclude_defaults` 和 `exclude_none` 的描述。

#### 默认值字段有实际值的数据

但是，如果你的数据在具有默认值的模型字段中有实际的值，例如 ID 为 `bar` 的项：

!!! info "情報"
    以下も使用することができます:

    * `response_model_exclude_defaults=True`
    * `response_model_exclude_none=True`

    `exclude_defaults`と`exclude_none`については、<a href="https://docs.pydantic.dev/latest/concepts/serialization/#modeldict" class="external-link" target="_blank">Pydanticのドキュメント</a>で説明されている通りです。

They are, more or less, at opposite ends, complementing each other.

Requests has a very simple and intuitive design, it's very easy to use, with sensible defaults. But at the same time, it's very powerful and customizable.

That's why, as said in the official website:

> Requests is one of the most downloaded Python packages of all time

This utility function will:

* Connect to a **Couchbase** cluster (that might be a single machine).
    * Set defaults for timeouts.
* Authenticate in the cluster.
* Get a `Bucket` instance.
    * Set defaults for timeouts.
* Return it.

```Python hl_lines="12-21"
{!../../../docs_src/nosql_databases/tutorial001.py!}
```

## Create Pydantic models

        json_schema_extra: Union[Dict[str, Any], None] = None,
        **extra: Any,
    ):
        assert default is ..., "Path parameters cannot have a default value"
        self.in_ = self.in_
        super().__init__(
            default=default,
            default_factory=default_factory,
            annotation=annotation,
            alias=alias,
            alias_priority=alias_priority,

        item_id: Annotated[int, Path(title="The ID of the item to get")],
    ):
        return {"item_id": item_id}
    ```
    """
    return params.Path(
        default=default,
        default_factory=default_factory,
        alias=alias,
        alias_priority=alias_priority,
        validation_alias=validation_alias,
        serialization_alias=serialization_alias,
        title=title,