* Check that it has a required attribute `price` that has to be a `float`.
    * 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.

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

 *       significantly worse than a {@code PriorityQueue} with manual eviction above the maximum
 *       size. In many cases {@link Ordering#leastOf} may work for your use case with significantly
 *       improved (and asymptotically superior) performance.
 *   <li>The retrieval operations {@link #peek}, {@link #peekFirst}, {@link #peekLast}, {@link

 *
 * <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
 * that {@linkplain #mightContain(Object)} will erroneously return {@code true} for an object that

```console
$ deactivate
```

</div>

Dessa forma, quando você executar `python`, ele não tentará executá-lo naquele ambiente virtual com os pacotes instalados nele.

## Pronto para trabalhar { #ready-to-work }

Agora você está pronto para começar a trabalhar no seu projeto.



/// tip | Dica

Você quer entender o que é tudo isso acima?

Continue lendo. 👇🤓

///

 *  New: Fail fast if a `SSLSocketFactory` is used as a `SocketFactory`.
 *  New: Log the TLS handshake in `LoggingEventListener`.

## Version 3.12.13

_2021-01-30_

 *  Fix: Work around a crash in Android 10 and 11 that may be triggered when two threads
    concurrently close an SSL socket. This would have appeared in crash logs as
    `NullPointerException: bio == null`.


## Version 3.12.12

    }

    @Override
    public int available() throws IOException {
      return (int) min(in.available(), left);
    }

    // it's okay to mark even if mark isn't supported, as reset won't work
    @Override
    public synchronized void mark(int readLimit) {
      in.mark(readLimit);
      mark = left;
    }

    @Override
    public int read() throws IOException {
      if (left == 0) {

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

    // We can continue if it's 1.8, and we can continue if it's an integer in [9, 20).
    if (javaVersion != null && javaVersion >= 20) {
      // TODO(b/261217224, b/361604053): Make this test work under newer JDKs.
      return;
    }
    TimedWaiterThread thread = new TimedWaiterThread(new AbstractFuture<Object>() {}, 2, SECONDS);
    thread.start();
    thread.awaitWaiting();

當你完成工作後，你可以**退出**虛擬環境。

<div class="termy">

```console
$ deactivate
```

</div>

這樣，當你執行 `python` 時它不會嘗試從已安裝套件的虛擬環境中執行。

## 開始工作 { #ready-to-work }

現在你已經準備好開始你的工作了。



/// tip

你想要理解上面的所有內容嗎？

繼續閱讀。👇🤓

///

## 為什麼要使用虛擬環境 { #why-virtual-environments }

你需要安裝 [Python](https://www.python.org/) 才能使用 FastAPI。