re.split(r'\W+', 'Words, words, words.') output ['Words', 'words', 'words', ''] : <p>I read the example in Python official docs reference to regex 
<a href="https://docs.python.org/3.7/library/re.html#re.split" rel="nofollow noreferrer">re.split()</a></p>

<pre><code>&gt;&gt;&gt; re.split(r'\W+', 'Words, words, words.')
['Words', 'words', 'words', '']
</code></pre>

<p>I am confused with the output, I guess it will produce</p>

<pre><code>[",",  ",",  ","]
</code></pre>

<p>I think the following is legible:</p>

<pre><code>In [100]: re.split(r',', 'Words, words, words.')
Out[100]: ['Words', ' words', ' words.']
</code></pre>

<p>How could <code>(r'\W+', 'Words, words, words.'</code> output that match?</p>
