=== "Python 3.10+"

    ```Python hl_lines="12"
    {!> ../../../docs_src/body_nested_models/tutorial002_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002.py!}
    ```

## Типы множеств

* 📝 Fix example code with sets in Tutorial - Body - Nested Models 3. PR [#2054](https://github.com/tiangolo/fastapi/pull/2054) by [@hitrust](https://github.com/hitrust).
* 📝 Fix example code with sets in Tutorial - Body - Nested Models 2. PR [#2053](https://github.com/tiangolo/fastapi/pull/2053) by [@hitrust](https://github.com/hitrust).

=== "Python 3.10+"

    ```Python hl_lines="12"
    {!> ../../../docs_src/body_nested_models/tutorial002_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002.py!}
    ```

## Set-Typen

    assert response.json() == {"foo": "baz"}


def test_nested_router():
    app = FastAPI()

    router = APIRouter(prefix="/nested")

    @router.get("/test")
    async def test(var: Annotated[str, Query()] = "bar"):
        return {"foo": var}

    app.include_router(router)

    client = TestClient(app)

    response = client.get("/nested/test")
    assert response.status_code == 200

It is also built to work as a future reference.

So you can come back and see exactly what you need.

## Run the code

All the code blocks can be copied and used directly (they are actually tested Python files).

To run any of the examples, copy the code to a file `main.py`, and start `uvicorn` with:

<div class="termy">

```console
$ uvicorn main:app --reload

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)


Daha önceden düşünüp en imkansız diyebileceğin durumlarda bile otomatik tamamlama alacaksın, örnek olarak `price` JSON body içerisinde (nested bir JSON body de olabilirdi.) direkt olarak istekten geliyor, bu durumda bile oto-tammalama sağlıyor.

    * Check that it has an optional attribute `is_offer`, that should be a `bool`, if present.
    * All this would also work for deeply nested JSON objects.
* Convert from and to JSON automatically.
* Document everything with OpenAPI, that can be used by:
    * Interactive documentation systems.
    * Automatic client code generation systems, for many languages.

It's the most popular Python framework and is widely trusted. It is used to build systems like Instagram.

It's relatively tightly coupled with relational databases (like MySQL or PostgreSQL), so, having a NoSQL database (like Couchbase, MongoDB, Cassandra, etc) as the main store engine is not very easy.

from fastapi import FastAPI
from fastapi.responses import ORJSONResponse
from fastapi.testclient import TestClient
from sqlalchemy.sql.elements import quoted_name

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():

This way, its schema will show up in the API docs user interface:

<img src="/img/tutorial/dataclasses/image01.png">

## Dataclasses in Nested Data Structures

You can also combine `dataclasses` with other type annotations to make nested data structures.

In some cases, you might still have to use Pydantic's version of `dataclasses`. For example, if you have errors with the automatically generated API documentation.