Python tuple weirdness
<p>I just came across something that was quite strange. </p>

<pre><code>&gt;&gt;&gt; t = ([],)
&gt;&gt;&gt; t[0].append('hello')
&gt;&gt;&gt; t
(['hello'],)
&gt;&gt;&gt; t[0] += ['world']
Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
TypeError: 'tuple' object does not support item assignment
&gt;&gt;&gt; t
(['hello', 'world'],)
</code></pre>

<p>Why does it raise <code>TypeError</code> and yet change the <code>list</code> inside the <code>tuple</code>?  </p>
