Para definir un `dict` le pasas 2 sub-tipos separados por comas.

El primer sub-tipo es para los keys del `dict`.

El segundo sub-tipo es para los valores del `dict`:

```Python hl_lines="1  4"
{!../../../docs_src/python_types/tutorial008.py!}
```

Esto significa:

* La variable `prices` es un `dict`:
    * Los keys de este `dict` son de tipo `str` (Digamos que son el nombre de cada ítem).

            continue
        code = lang_path.name
        languages.append({code: f"/{code}/"})
    for lang_dict in languages:
        code = list(lang_dict.keys())[0]
        url = lang_dict[code]
        if code not in local_language_names:
            print(
                f"Missing language name for: {code}, "
                "update it in docs/language_names.yml"

        encoded_dict = {}
        allowed_keys = set(obj.keys())
        if include is not None:
            allowed_keys &= set(include)
        if exclude is not None:
            allowed_keys -= set(exclude)
        for key, value in obj.items():
            if (
                (
                    not sqlalchemy_safe
                    or (not isinstance(key, str))
                    or (not key.startswith("_sa"))

```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",
}
```

We can do better...

## What makes a dependency

Up to now you have seen dependencies declared as functions.

But that's not the only way to declare dependencies (although it would probably be the more common).

The key factor is that a dependency should be a "callable".

    """

    def render(self, content: Any) -> bytes:
        assert orjson is not None, "orjson must be installed to use ORJSONResponse"
        return orjson.dumps(
            content, option=orjson.OPT_NON_STR_KEYS | orjson.OPT_SERIALIZE_NUMPY

You can also declare a body as a `dict` with keys of some type and values of some other type.

This way, you don't have to know beforehand what the valid field/attribute names are (as would be the case with Pydantic models).

This would be useful if you want to receive keys that you don't already know.

---

Another useful case is when you want to have keys of another type (e.g., `int`).

app = FastAPI(default_response_class=ORJSONResponse)


@app.get("/orjson_non_str_keys")
def get_orjson_non_str_keys():
    key = quoted_name(value="msg", quote=False)
    return {key: "Hello World", 1: 1}


client = TestClient(app)


def test_orjson_non_str_keys():
    with client:
        response = client.get("/orjson_non_str_keys")

# Settings and Environment Variables

In many cases your application could need some external settings or configurations, for example secret keys, database credentials, credentials for email services, etc.

Most of these settings are variable (can change), like database URLs. And many could be sensitive, like secrets.

For this reason it's common to provide them in environment variables that are read by the application.

## Environment Variables

!!! tip

}

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

!!! info
    `**second_user_data` significa:

    Pasa las <abbr title="en español key se refiere a la guía de un diccionario">keys</abbr> y los valores del dict `second_user_data` directamente como argumentos de key-value, equivalente a: `User(id=4, name="Mary", joined="2018-11-30")`

### Soporte del editor