<li><strong>By default digits, whitespaces and alphanumerics from all alphabets are matched, unless <codeclass="python hljs"><spanclass="hljs-string">'flags=re.ASCII'</span></code> argument is used.</strong></li>
<li><strong>Use capital letter for negation.</strong></li>
</ul><pre><codeclass="python language-python hljs"><spanclass="hljs-string">'\d'</span> == <spanclass="hljs-string">'[0-9]'</span><spanclass="hljs-comment"># Matches any digit.</span>
<spanclass="hljs-string">'\s'</span> == <spanclass="hljs-string">'[ \t\n\r\f\v…]'</span><spanclass="hljs-comment"># Matches any whitespace.</span>
<spanclass="hljs-string">'\w'</span> == <spanclass="hljs-string">'[a-zA-Z0-9_]'</span><spanclass="hljs-comment"># Matches any alphanumeric.</span>
<spanclass="hljs-string">'\s'</span> == <spanclass="hljs-string">'[ \t\n\r\f\v]'</span><spanclass="hljs-comment"># Matches any whitespace.</span>