## Recap

You have been reading here some of the main concepts that you would probably need to keep in mind when deciding how to deploy your application:

* Security - HTTPS
* Running on startup
* Restarts

### Create Pydantic *models* / schemas for reading / returning

Now create Pydantic *models* (schemas) that will be used when reading data, when returning it from the API.

For example, before creating an item, we don't know what will be the ID assigned to it, but when reading it (when returning it from the API) we will already know its ID.

  So they began solemnly dancing round and round Alice, every now
and then treading on her toes when they passed too close, and
waving their forepaws to mark the time, while the Mock Turtle
sang this, very slowly and sadly:--


`"Will you walk a little faster?" said a whiting to a snail.
"There's a porpoise close behind us, and he's treading on my
 tail.
See how eagerly the lobsters and the turtles all advance!

### Creating the `Settings` only once with `lru_cache`

Reading a file from disk is normally a costly (slow) operation, so you probably want to do it only once and then re-use the same settings object, instead of reading it for each request.

But every time we do:

```Python
Settings()
```

Aún así, en ambas situaciones, es probable que **FastAPI** sea [aún más rápido](index.md#rendimiento){.Internal-link target=_blank} que (o al menos comparable) a tu framework anterior.

That's why in this example we have to declare it in the `response_model` parameter.

...but continue reading below to see how to overcome that.

## Return Type and Data Filtering

Let's continue from the previous example. We wanted to **annotate the function with one type** but return something that includes **more data**.

### <a href="https://webargs.readthedocs.io/en/latest/" class="external-link" target="_blank">Webargs</a>

Another big feature required by APIs is <abbr title="reading and converting to Python data">parsing</abbr> data from incoming requests.

Webargs is a tool that was made to provide that on top of several frameworks, including Flask.

!!! check "😮 **FastAPI** "
    ⚙️ 📟 🔬 "🔗" 👈 🚚 💽 🆎 & 🔬, 🔁.

### <a href="https://webargs.readthedocs.io/en/latest/" class="external-link" target="_blank">Webarg</a>

➕1️⃣ 🦏 ⚒ ✔ 🔗 <abbr title="reading and converting to Python data">✍</abbr> 📊 ⚪️➡️ 📨 📨.

Webarg 🧰 👈 ⚒ 🚚 👈 🔛 🔝 📚 🛠️, 🔌 🏺.

⚫️ ⚙️ 🍭 🔘 💽 🔬. &amp; ⚫️ ✍ 🎏 👩‍💻.

⚫️ 👑 🧰 &amp; 👤 ✔️ ⚙️ ⚫️ 📚 💁‍♂️, ⏭ ✔️ **FastAPI**.

!!! info

* Add a check for file size if the reading content returns empty ([#33976](https://github.com/kubernetes/kubernetes/pull/33976), [@jingxu97](https://github.com/jingxu97))
* Add a retry when reading a file content from a container ([#35560](https://github.com/kubernetes/kubernetes/pull/35560), [@jingxu97](https://github.com/jingxu97))

    val response = call.execute()
    val inputStream = response.body.byteStream()
    assertThat(inputStream.read().toChar()).isEqualTo('A')
    call.cancel()
    assertFailsWith<IOException> {
      // Reading 'B' may succeed if it's buffered.
      inputStream.read()

      // But 'C' shouldn't be buffered (the response is throttled) and this should fail.
      inputStream.read()
    }
    inputStream.close()