Best way to check if a list is empty
<p>For example, if passed the following:</p>

<pre><code>a = []
</code></pre>

<p>How do I check to see if <code>a</code> is empty?</p>

<pre><code>if not a:
  print("List is empty")
</code></pre>

<p>Using the implicit booleanness of the empty list <code>a</code> is quite pythonic.</p>
