How should I fix this - 'int' object is not iterable? : <p>Unlike other questions, I'm getting this error <em>without</em> using a looping construct.</p>

<p>Here's the code</p>

<pre><code>def makes_twenty(n1,n2):
    return ( (sum(n1, n2) == 20) or ((n1 == 20) or (n2 == 20)) )
</code></pre>

<p>The error I receive - 
<code>'int' object is not iterable</code>
<a href="https://i.stack.imgur.com/hwPaN.png" rel="nofollow noreferrer">Screenshot of the code with error</a></p>

<p>The irony is, if I change this thing - 
<code>sum(n1, n2)</code>
Into something like this - 
<code>(n1 + n2)</code>
The code works fine.
<a href="https://i.stack.imgur.com/nw2YD.png" rel="nofollow noreferrer">Screenshot of corrected code</a>
I wonder what's happening here.</p>
