title: Iterating over list of dictionaries in 2 dimensional list comprehension
body: <p>I don't understand why this list comprehension isn't correct. If I understand list comprehensions correctly, it should first iterate over the dictionaries in the list [dict1, dict2] and then over key-value pairs in each dictionary and return the values. Were am I wrong?</p>
  
  <pre><code>dict1 = {'a' : 1, 'b' : 2, 'c' : 3}
  dict2 = {'c' : 2, 'd' : 3, 'e' : 4}
  [value for key, value in d.items()
         for d in [dict1, dict2]]
  </code></pre>
  
  <p>It gives the following error:</p>
  
  <pre><code>NameError                                 Traceback (most recent call last)
  &lt;ipython-input-78-e8d31c1fb24a&gt; in &lt;module&gt;()
        1 dict1 = {'a' : 1, 'b' : 2, 'c' : 3}
        2 dict2 = {'c' : 2, 'd' : 3, 'e' : 4}
  ----&gt; 3 [value for (key, value) in d.items() 
        4        for d in [dict1, dict2]]
  
  NameError: name 'd' is not defined
  </code></pre>
  
  <p>I would expect:</p>
  
  <pre><code>[1,2,3,2,3,4]
  </code></pre>