擅长:python、mysql、java
<p><code>r</code>不表示“regex string”;它的意思是“raw string”。根据<a href="http://docs.python.org/2/reference/lexical_analysis.html#string-literals">the docs</a>:</p>
<blockquote>
<p>String literals may optionally be prefixed with a letter <code>'r'</code> or <code>'R'</code>; such strings are called <em>raw strings</em> and use different rules for interpreting backslash escape sequences.</p>
</blockquote>