```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009b.py!}
```

////

#### Sử dụng `Union` hay `Optional`

If you are using a Python version below 3.10, here's a tip from my very **subjective** point of view:

Nếu bạn đang sử dụng phiên bản Python dưới 3.10, đây là một mẹo từ ý kiến rất "chủ quan" của tôi:

* 🚨 Tránh sử dụng `Optional[SomeType]`

///

## Create a Project

First, create a directory for your project.

What I normally do is that I create a directory named `code` inside my home/user directory.

And inside of that I create one directory per project.

<div class="termy">

```console
// Go to the home directory
$ cd
// Create a directory for all your code projects
$ mkdir code

		0, nil, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)

	// execute the HTTP request.
	response, err = s.client.Do(request)

	c.Assert(err, nil)
	c.Assert(response.StatusCode, http.StatusOK)

	request, err = newTestSignedRequest(http.MethodGet, getGetObjectURL(s.endPoint, bucketName, "my-object-directory/"),

## نظر دیگران در مورد FastAPI

<div style="text-align: left; direction: ltr;"> [...] I'm using <strong>FastAPI</strong> a ton these days. [...] I'm actually planning to use it for all of my team's <strong>ML services at Microsoft</strong>. Some of them are getting integrated into the core <strong>Windows</strong> product and some <strong>Office</strong> products."</div>

  // the associated expression.
  // Name must be a qualified name consisting of alphanumeric characters, '-', '_' or '.', and
  // must start and end with an alphanumeric character (e.g. 'MyName',  or 'my.name',  or
  // '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]') with an
  // optional DNS subdomain prefix and '/' (e.g. 'example.com/MyName')
  //
  // Required.
  optional string name = 1;

<a href="https://fastapi.tiangolo.com/fastapi-people/#sponsors" class="external-link" target="_blank">Other sponsors</a>

## Opinions

"_[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products._"

  // the associated expression.
  // Name must be a qualified name consisting of alphanumeric characters, '-', '_' or '.', and
  // must start and end with an alphanumeric character (e.g. 'MyName',  or 'my.name',  or
  // '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]') with an
  // optional DNS subdomain prefix and '/' (e.g. 'example.com/MyName')
  //
  // Required.
  optional string name = 1;

es‘ÑJ©¤SizeÑJ©¥MTimeÓ ¹ô‡‰O/>§MetaSys ¼x-minio-internal-inline-dataÄ true§MetaUsr‚¬content-type­text/markdown¤etagÙ 4af243ccccbadaf12545¡vÎeçnÐδg»Ä ¤nullÅ%uûc¿“êíûO á §hÁ¿ÂÄ·Î,2ù ÞV² 6R6u2·¾ çò] „ ]iyýYVa~v„ yûJEØέ¡ µXiA[5¦dN@^Í ¯µA~eMýªi}d g )Õv mý…vMFe¯Õ~c›?ª~^tBK’1•_VIwY¸÷s`”SU©¤ ‹' ñmwON¾ MhzÕ}ªd Ð{œ™¡û=M°sR_eô*Kºim¿ðñ)cKÖ»`w~h]» ûzq]»oeRa{®}Úk ãh'wg­œ¸Ž–Œ ;/²XDBbÕÔ£­* æœ~Yuý%r°C[S»Ö÷is`g 1}gp i»³ ·# Tqc}~Gi% `nÄÐ{œ™¡ûué&Ojg}nFO&ûo½æËìaK£XqCïR_K7Y ,Fñ 0±›lPÃïÝ-²ø* BIÜï1#_^^uB¸å7i¹}û,W{•[ixU...

  @IgnoreJRERequirement // helper for toImmutableSortedMultiset
  /*
   * If we make these calls inline inside toImmutableSortedMultiset, we get an Animal Sniffer error,
   * despite the @IgnoreJRERequirement annotation there. My assumption is that, because javac
   * generates a synthetic method for the body of the lambda, the actual method calls that Animal
   * Sniffer is flagging don't appear inside toImmutableSortedMultiset but rather inside that

      if (wrapper.getCause() instanceof Error) {
        throw new ExecutionError((Error) wrapper.getCause());
      }
      /*
       * It's an Exception. (Or it's a non-Error, non-Exception Throwable. From my survey of such
       * classes, I believe that most users intended to extend Exception, so we'll treat it like an
       * Exception.)
       */
      throw new UncheckedExecutionException(wrapper.getCause());
    }