/// info

Keep in mind that dataclasses can't do everything Pydantic models can do.

So, you might still need to use Pydantic models.

But if you have a bunch of dataclasses laying around, this is a nice trick to use them to power a web API using FastAPI. 🤓

///

## Dataclasses in `response_model` { #dataclasses-in-response-model }

You can also use `dataclasses` in the `response_model` parameter:

With just that Python type declaration, **FastAPI** will:

* Read the body of the request as JSON.
* Convert the corresponding types (if needed).
* Validate the data.
    * If the data is invalid, it will return a nice and clear error, indicating exactly where and what was the incorrect data.
* Give you the received data in the parameter `item`.

///

## Data validation { #data-validation }

But if you go to the browser at <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, you will see a nice HTTP error of:

```JSON
{
  "detail": [
    {
      "type": "int_parsing",
      "loc": [
        "path",
        "item_id"
      ],

      <activation>
        <property>
          <name>surefire.toolchain.version</name>
          <!-- the value provided by GitHub CI (which maybe we could even change, but supporting "8" seems nice for any users who try pass that value manually) -->
          <value>8</value>
        </property>
      </activation>
      <properties>
        <test.add.opens></test.add.opens>
      </properties>

      <activation>
        <property>
          <name>surefire.toolchain.version</name>
          <!-- the value provided by GitHub CI (which maybe we could even change, but supporting "8" seems nice for any users who try pass that value manually) -->
          <value>8</value>
        </property>
      </activation>
      <properties>
        <test.add.opens></test.add.opens>
      </properties>

<img src="/img/async/concurrent-burgers/concurrent-burgers-06.png" class="illustration">

You and your crush eat the burgers and have a nice time. ✨

<img src="/img/async/concurrent-burgers/concurrent-burgers-07.png" class="illustration">

/// info

 * but if it claims that an element is <i>not</i> contained in it, then this is definitely true.
 *
 * <p>If you are unfamiliar with Bloom filters, this nice <a
 * href="http://llimllib.github.io/bloomfilter-tutorial/">tutorial</a> may help you understand how
 * they work.
 *
 * <p>The false positive probability ({@code FPP}) of a Bloom filter is defined as the probability

Cognito - author: Ankush Thakur author_link: https://geekflare.com/author/ankush/ link: https://geekflare.com/python-asynchronous-web-frameworks/ title: Top 5 Asynchronous Web Frameworks for Python - author: Nico Axtmann author_link: https://www.linkedin.com/in/nico-axtmann link: https://medium.com/@nico.axtmann95/deploying-a-scikit-learn-model-with-onnx-und-fastapi-1af398268915 title: Deploying a scikit-learn model with ONNX and FastAPI - author: Nils de Bruin author_link: https://medium.com/@nilsdebruin...

  url: https://github.com/frankie567
marier-nico:
  login: marier-nico
  count: 2
  avatarUrl: https://avatars.githubusercontent.com/u/30477068?u=c7df6af853c8f4163d1517814f3e9a0715c82713&v=4
  url: https://github.com/marier-nico
Dustyposa:
  login: Dustyposa
  count: 2

Luego es tu turno, haces tu pedido de 2 hamburguesas muy sofisticadas para tu crush y para ti. 🍔🍔

<img src="/img/async/concurrent-burgers/concurrent-burgers-02.png" class="illustration">

El cajero dice algo al cocinero en la cocina para que sepan que tienen que preparar tus hamburguesas (aunque actualmente están preparando las de los clientes anteriores).