What is your favorite feature of Python?
<p><strong>Dupe: <a href="http://stackoverflow.com/questions/101268/hidden-features-of-python">http://stackoverflow.com/questions/101268/hidden-features-of-python</a></strong></p>

<p>What is a feature you could not live without when using Python?  </p>

<p>If you don't mind bold face it at the top :) and the give a short explanation why you can't live without it or a short example of what it can do.  If you see it already on the list, up vote that person and then add your reason in a comment.</p>

<p> List comprehensions 

<ul>
<li> short and concise </li>
<li> easy to read </li>
<li> powerful </li>
</ul>

<p>They can be used as generators:</p>

<pre><code>for something in (x for x in xrange(huge_number)):
    do_something_crazy(x)
</code></pre>

<p>They can also be nested which can replace a huge amount of nested for loops:</p>

<pre><code>[(i, j) for i in range(10) for j in range(10)]
</code></pre>

<p>List comprehensions are a pretty powerful construct.  Some basic info on them can be found <a href="http://docs.python.org/tutorial/datastructures.html#list-comprehensions" rel="nofollow">here</a>.</p>
