Good advice for coming to javascript (from Python)
<p>I am coming to JavaScript, from Python.  </p>

<p>I want to write testable, modular JS code, and want advice on tools, best practices and the like.  I know about:</p>

<ul>
<li><a href="http://www.jslint.com/" rel="nofollow">JSLint</a> (and the existence of <a href="http://javascript.crockford.com/" rel="nofollow">Douglas Crockford</a>)</li>
<li>Paul Irish (hi Paul!) and the <a href="http://paulirish.com/2010/10-things-i-learned-from-the-jquery-source/" rel="nofollow">10 Things...From the jQuery Source</a> podcast</li>
<li>jQuery, jQuery.ui and Themeroller</li>
<li>the existence of freenode#javascript and freenode#jquery</li>
<li><a href="https://developer.mozilla.org/en/JavaScript" rel="nofollow">Mozilla's MDC Doc Center</a></li>
</ul>

<p>Stumbling blocks (so far):</p>

<p>What am I missing?  Idioms / techniques / tools welcome, particularly around arrays (which seem crippled compared to python lists... what am I missing?), namespacing, testing, and documentation (no docstrings?  what do I do instead?)</p>

<p>(also, are we not allowed to tag things as community wiki anymore?  I don't need the rep!)</p>

<p>Also, one answer per response please!</p>
