<li><strong>Use <codeclass="python hljs"><spanclass="hljs-string">r'\1'</span></code> or <codeclass="python hljs"><spanclass="hljs-string">'\\1'</span></code> for backreference.</strong></li>
<li><strong>Use <codeclass="python hljs"><spanclass="hljs-string">r'\1'</span></code> or <codeclass="python hljs"><spanclass="hljs-string">'\\1'</span></code> for backreference.</strong></li>
<li><strong>Add <codeclass="python hljs"><spanclass="hljs-string">'?'</span></code> after an operator to make it non-greedy.</strong></li>
<li><strong>Add <codeclass="python hljs"><spanclass="hljs-string">'?'</span></code> after an operator to make it non-greedy.</strong></li>
<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>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 letters for negation.</strong></li>
<li><strong>Use capital letters for negation.</strong></li>