What is the pythonic way to avoid default parameters that are empty lists?
<p>Sometimes it seems natural to have a default parameter which is an empty list. Yet Python gives unexpected behavior in these situations.  </p>

<p>If for example, I have a function:</p>

<pre><code>def myFunc(working_list = []):
    working_list.append("a")
    print working_list
</code></pre>

<p>The first time it is called with the default will work, but calls after that will use a constantly updating list.</p>

<p>So, what is the pythonic way to get the behavior I desire (a fresh list on each call)?</p>
