Python sum array of objects into objects
<p>I have a list (name=carpet) of objects type mini_carpet.
Mini_carpet contains a list of objects called packages.
Packages has various properties, the one interesting to me is nr_buys.</p>

<p>What I want to do is to sum the various nr_buys that are within a mini_carpet, within a carpet.
This is what I have done so far:</p>

<pre><code>for d in range(0, carpet.__len__() - 1, +1):
nr_total = sum(carpet[d].packages[i].nr_buys for i in carpet[d].packages)
</code></pre>

<p>This is giving me an error because list indices must be integers.
Any help?</p>

<p>Thanks! </p>

<p>When you've already coded the __len__ method, u dont need to call it by <code>carpet.__len__()</code>. Instead of use <code>len(carpet)</code>.</p>

python