title: python reduce issue object has no attribute
body: <p><code>snds</code> is a collection of nodes , which has the attribute of 'alloc'. the following two statements looks equivalent to me, but the first throw error    <code>AttributeError: 'int' object has no attribute 'alloc'</code></p>
  
  <p>I might have made some stupid mistake some where which I can't discover. </p>
  
  <pre><code>#return reduce( lambda x,y:x.alloc+y.alloc, snds)
  return reduce( lambda x,y:x+y, map( lambda x:x.alloc, snds) )
  </code></pre>