* Show a **clear error** for the client when the data is not valid
* **Document** the parameter in the OpenAPI schema *path operation* (so it will show up in the **automatic docs UI**)

## Alternative (old) `Query` as the default value

                **Example**

                ```python
                from fastapi import FastAPI

                from .internal import old_api

                app = FastAPI()

                app.include_router(
                    old_api.router,
                    deprecated=True,
                )
                ```
                """
            ),
        ] = None,

```Python
old_dict = {
    "old key": "old value",
    "second old key": "second old value",
}
new_dict = {**old_dict, "new key": "new value"}
```

Hier wird `new_dict` alle Schlüssel-Wert-Paare von `old_dict` plus das neue Schlüssel-Wert-Paar enthalten:

```Python
{
    "old key": "old value",
    "second old key": "second old value",
    "new key": "new value",
}
```

```Python
old_dict = {
    "old key": "old value",
    "second old key": "second old value",
}
new_dict = {**old_dict, "new key": "new value"}
```

Here, `new_dict` will contain all the key-value pairs from `old_dict` plus the new key-value pair:

```Python
{
    "old key": "old value",
    "second old key": "second old value",
    "new key": "new value",
}
```

📚 💼, 👆 💪 ⚙️ 🐍 ⚒ "🏗" `dict` ⏮️ `**dict_to_unpack`:

```Python
old_dict = {
    "old key": "old value",
    "second old key": "second old value",
}
new_dict = {**old_dict, "new key": "new value"}
```

📥, `new_dict` 🔜 🔌 🌐 🔑-💲 👫 ⚪️➡️ `old_dict` ➕ 🆕 🔑-💲 👫:

```Python
{
    "old key": "old value",
    "second old key": "second old value",
    "new key": "new value",
}
```

    * `Body()`
    * `File()`
    * `Form()`

!!! info
    This old OpenAPI-specific `examples` parameter is now `openapi_examples` since FastAPI `0.103.0`.

### JSON Schema's `examples` field