// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

		total:             "Total memory on the node",
		memUsed:           "Used memory on the node",
		memUsedPerc:       "Used memory percentage on the node",
		memFree:           "Free memory on the node",
		memShared:         "Shared memory on the node",
		memBuffers:        "Buffers memory on the node",
		memCache:          "Cache memory on the node",
		memAvailable:      "Available memory on the node",

{!> ../../docs_src/body/tutorial001.py!}
```

////

与声明查询参数一样，包含默认值的模型属性是可选的，否则就是必选的。默认值为 `None` 的模型属性也是可选的。

例如，上述模型声明如下 JSON **对象**（即 Python **字典**）：

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

……由于 `description` 和 `tax` 是可选的（默认值为 `None`），下面的 JSON **对象**也有效：

```JSON
{
    "name": "Foo",
    "price": 45.2
}
```

### Node binaries

filename | sha512 hash
-------- | -----------
[kubernetes-node-linux-amd64.tar.gz](https://dl.k8s.io/v1.17.17/kubernetes-node-linux-amd64.tar.gz) | 40518e641695635e05845fca17faef6b21adfc21484c29b8c30f3478adf6fd6d1f7014ac82526109e00f8007ebb1ba5a3570f0bfc7eca64eb66c097658b3f791

* 🚥 🔢 📣 **➡**, ⚫️ 🔜 ⚙️ ➡ 🔢.
* 🚥 🔢 **⭐ 🆎** (💖 `int`, `float`, `str`, `bool`, ♒️) ⚫️ 🔜 🔬 **🔢** 🔢.
* 🚥 🔢 📣 🆎 **Pydantic 🏷**, ⚫️ 🔜 🔬 📨 **💪**.

/// note

FastAPI 🔜 💭 👈 💲 `q` 🚫 ✔ ↩️ 🔢 💲 `= None`.

 `Union` `Union[str, None]` 🚫 ⚙️ FastAPI, ✋️ 🔜 ✔ 👆 👨‍🎨 🤝 👆 👍 🐕‍🦺 & 🔍 ❌.

///

## 🍵 Pydantic

```Python hl_lines="19-24  28"
{!../../docs_src/additional_responses/tutorial002.py!}
```

/// note

👀 👈 👆 ✔️ 📨 🖼 ⚙️ `FileResponse` 🔗.

///

/// info

🚥 👆 ✔ 🎏 📻 🆎 🎯 👆 `responses` 🔢, FastAPI 🔜 🤔 📨 ✔️ 🎏 📻 🆎 👑 📨 🎓 (🔢 `application/json`).

✋️ 🚥 👆 ✔️ ✔ 🛃 📨 🎓 ⏮️ `None` 🚮 📻 🆎, FastAPI 🔜 ⚙️ `application/json` 🙆 🌖 📨 👈 ✔️ 👨‍💼 🏷.

///

## 🌀 ℹ

* 만약 매개변수가 (`int`, `float`, `str`, `bool` 등과 같은) **유일한 타입**으로 되어있으면, **쿼리** 매개변수로 해석될 것입니다.
* 만약 매개변수가 **Pydantic 모델** 타입으로 선언되어 있으면, 요청 **본문**으로 해석될 것입니다.

/// note | "참고"

FastAPI는 `q`의 값이 필요없음을 알게 될 것입니다. 기본 값이 `= None`이기 때문입니다.

`Union[str, None]`에 있는 `Union`은 FastAPI에 의해 사용된 것이 아니지만, 편집기로 하여금 더 나은 지원과 에러 탐지를 지원할 것입니다.

///

## Pydantic없이

### GNU/Linux and macOS

```sh
docker-compose pull
docker-compose up
```

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@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):