python string u"%(word)s"
<p>i'm a new user of python , i don't know some place when i read the code . so i asked here.</p>

<pre><code>cmd = u"sudo umount %(mountpoint)s &gt;&gt;%(log)s 2&gt;&amp;1"
</code></pre>

<p>i know that <code>%(word)</code> is used to replace the word latter use such as <code>cmd % {'word':'new word'}</code>, but i don't down why there is a trailing <code>s</code>. and i don't know the 'u' meaning at the beginning of the string.</p>
