title: TypeError: <lambda>() takes exactly 1 argument (3 given)
body: <p>Given this code:</p>
  
  <pre><code>sumThree = lambda (x, y, z): (x[0]+ y[0] + z[0], x[1] + y[1] + z[1])
  print 'sumThree((1, 2), (3, 4), (5, 6)) = {0}'.format(sumThree((1, 2), (3, 4), (5, 6)))
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>TypeError                                 Traceback (most recent call last)
  &lt;ipython-input-43-7f1b9571e230&gt; in &lt;module&gt;()
       16 # second position summed. E.g. (1, 2), (3, 4), (5, 6) =&gt; (1 + 3 + 5, 2 + 4 + 6) =&gt; (9, 12)
       17 sumThree = lambda (x0, x1, x2): (x[0]+ y[0] + z[0], x[1] + y[1] + z[1])
  ---&gt; 18 print 'sumThree((1, 2), (3, 4), (5, 6)) = {0}'.format(sumThree((1, 2), (3, 4), (5, 6)))
  
  TypeError: &lt;lambda&gt;() takes exactly 1 argument (3 given)
  </code></pre>
  
  <p>And the question is of course, why?</p>