context = browser.new_context(viewport={"width": 960, "height": 1080})
    page = context.new_page()
    page.goto("http://localhost:8000/docs")
    page.get_by_text("POST/items/Create Item").click()
    page.get_by_role("tab", name="Schema").first.click()
    page.screenshot(
        path="docs/en/docs/img/tutorial/separate-openapi-schemas/image01.png"
    )

    # ---------------------
    context.close()
    browser.close()

### Model for Output in Docs

You can check the output model in the docs too, **both** `name` and `description` are marked as **required** with a **red asterisk**:

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image03.png">
</div>

### Model for Input and Output in Docs

SQLALCHEMY_DATABASE_URL = "sqlite:///./sql_app.db"
# SQLALCHEMY_DATABASE_URL = "postgresql://user:password@postgresserver/db"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

```

👉 💼, `item_id` 📣 `int`.

!!! check
    👉 🔜 🤝 👆 👨‍🎨 🐕‍🦺 🔘 👆 🔢, ⏮️ ❌ ✅, 🛠️, ♒️.

## 💽 <abbr title="also known as: serialization, parsing, marshalling">🛠️</abbr>

🚥 👆 🏃 👉 🖼 &amp; 📂 👆 🖥 <a href="http://127.0.0.1:8000/items/3" class="external-link" target="_blank">http://127.0.0.1:8000/items/3</a>, 👆 🔜 👀 📨:

```JSON
{"item_id":3}
```

!!! check

from sqlalchemy.pool import StaticPool

from ..database import Base
from ..main import app, get_db

SQLALCHEMY_DATABASE_URL = "sqlite://"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL,
    connect_args={"check_same_thread": False},
    poolclass=StaticPool,
)
TestingSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


Base.metadata.create_all(bind=engine)


def override_get_db():
    try:

You need to import `WSGIMiddleware`.

Then wrap the WSGI (e.g. Flask) app with the middleware.

And then mount that under a path.

```Python hl_lines="2-3  23"
{!../../../docs_src/wsgi/tutorial001.py!}
```

## Check it

Now, every request under the path `/v1/` will be handled by the Flask application.

And the rest will be handled by **FastAPI**.

    And as the `Response` can be used frequently to set headers and cookies, **FastAPI** also provides it at `fastapi.Response`.

And because you are using `StaticFiles`, that CSS file would be served automatically by your **FastAPI** application at the URL `/static/styles.css`.

## More details

## 선택적 매개변수

같은 방법으로 기본값을 `None`으로 설정하여 선택적 매개변수를 선언할 수 있습니다:

```Python hl_lines="9"
{!../../../docs_src/query_params/tutorial002.py!}
```

이 경우 함수 매개변수 `q`는 선택적이며 기본값으로 `None` 값이 됩니다.

!!! check "확인"
    **FastAPI**는 `item_id`가 경로 매개변수이고 `q`는 경로 매개변수가 아닌 쿼리 매개변수라는 것을 알 정도로 충분히 똑똑합니다.

!!! note "참고"
    FastAPI는 `q`가 `= None`이므로 선택적이라는 것을 인지합니다.

    ```

=== "Python 3.8+"

    ```Python hl_lines="9"
    {!> ../../../docs_src/query_params/tutorial002.py!}
    ```


本例中，查询参数 `q` 是可选的，默认值为 `None`。

!!! check "检查"

    注意，**FastAPI** 可以识别出 `item_id` 是路径参数，`q` 不是路径参数，而是查询参数。

!!! note "笔记"

    因为默认值为 `= None`，FastAPI 把 `q` 识别为可选参数。