<attr_name_3>: list/dict/set = field(default_factory=list/dict/set)

* **Objects can be made sortable with `'order=True'` and immutable with `'frozen=True'`.**

* **Function field() is needed because `'<attr_name>: list = []'` would make a list that is shared among all instances. Its 'default_factory' argument can be any [callable](#callable).**

* **For attributes of arbitrary type use `'typing.Any'`.**

WIKI_URL = 'https://en.wikipedia.org/wiki/Python_(programming_language)'

try:

version = table.find('th', text='Stable release').next_sibling.strings.__next__()

logo_url = table.find('img')['src']

logo = requests.get(f'https:{logo_url}').content

file.write(logo)

except requests.exceptions.ConnectionError:

print("You've got problems with connection.", file=sys.stderr)

<header>

<a href="https://gto76.github.io" rel="author">Jure Šorn</a>

</header>

<li><strong>Objects can be made sortable with <code class="python hljs"><span class="hljs-string">'order=True'</span></code> and immutable with <code class="python hljs"><span class="hljs-string">'frozen=True'</span></code>.</strong></li>

<li><strong>Function field() is needed because <code class="python hljs"><span class="hljs-string">'&lt;attr_name&gt;: list = []'</span></code> would make a list that is shared among all instances. Its 'default_factory' argument can be any <a href="#callable">callable</a>.</strong></li>

<li><strong>For attributes of arbitrary type use <code class="python hljs"><span class="hljs-string">'typing.Any'</span></code>.</strong></li>

<li><strong><code class="python hljs"><span class="hljs-string">'&lt;str&gt;'</span></code> - Max age as a string: <code class="python hljs"><span class="hljs-string">'1 week, 3 days'</span></code>, <code class="python hljs"><span class="hljs-string">'2 months'</span></code>, …</strong></li>

<div><h2 id="scraping"><a href="#scraping" name="scraping">#</a>Scraping</h2><div><h4 id="scrapespythonsurlversionnumberandlogofromitswikipediapage">Scrapes Python's URL, version number and logo from its Wikipedia page:</h4><pre><code class="python language-python hljs"><span class="hljs-comment"># $ pip3 install requests beautifulsoup4</span>

WIKI_URL = <span class="hljs-string">'https://en.wikipedia.org/wiki/Python_(programming_language)'</span>

<span class="hljs-keyword">try</span>:

version = table.find(<span class="hljs-string">'th'</span>, text=<span class="hljs-string">'Stable release'</span>).next_sibling.strings.__next__()

logo_url = table.find(<span class="hljs-string">'img'</span>)[<span class="hljs-string">'src'</span>]

logo = requests.get(<span class="hljs-string">f'https:<span class="hljs-subst">{logo_url}</span>'</span>).content

file.write(logo)

<span class="hljs-keyword">except</span> requests.exceptions.ConnectionError:

print(<span class="hljs-string">"You've got problems with connection."</span>, file=sys.stderr)

<footer>

<a href="https://gto76.github.io" rel="author">Jure Šorn</a>

</footer>

'<strong>Module <a href="#operator">operator</a> provides functions itemgetter() and mul() that offer the same functionality as <a href="#lambda">lambda</a> expressions above.</strong>': '<strong>Module \'operator\' (p. 31) provides functions itemgetter() and mul() that offer the same functionality as lambda expressions (p. 11) above.</strong>',

'<strong>Adding <code class="python hljs"><span class="hljs-string">\'!r\'</span></code> before the colon converts object to string by calling its <a href="#class">repr()</a> method.</strong>': '<strong>Adding <code class="python hljs"><span class="hljs-string">\'!r\'</span></code> before the colon converts object to string by calling its repr() method (p. 14).</strong>',

'<strong>It can be any <a href="#callable">callable</a>, but is usually implemented as a function that returns a <a href="#closure">closure</a>.</strong>': '<strong>It can be any callable (p. 17), but is usually implemented as a function that returns a closure (p. 12).</strong>',

'<strong>Function field() is needed because <code class="python hljs"><span class="hljs-string">\'&lt;attr_name&gt;: list = []\'</span></code> would make a list that is shared among all instances. Its \'default_factory\' argument can be any <a href="#callable">callable</a>.</strong>': '<strong>Function field() is needed because <code class="python hljs"><span class="hljs-string">\'&lt;attr_name&gt;: list = []\'</span></code> would make a list that is shared among all instances. Its \'default_factory\' argument can be any callable (p. 17).</strong>',

'<strong>Sequence iterators returned by the <a href="#iterator">iter()</a> function, such as list_iterator and set_iterator.</strong>': '<strong>Sequence iterators returned by the iter() function, such as list_iterator and set_iterator (p.&nbsp;3).</strong>',

'<strong>Objects returned by the <a href="#itertools">itertools</a> module, such as count, repeat and cycle.</strong>': '<strong>Objects returned by the itertools module, such as count, repeat and cycle (p. 3).</strong>',