title: Inconsistency between %time and %timeit in IPython
body: <p>I am confronted to a weird situation that I can't explain. Here is my test timing the generation of a large list of tuples:</p>
  
  <pre><code>In [1]: def get_list_of_tuples():
     ...:     return [(i,) for i in range(10**6)]
     ...:
  
  In [2]: %time res = get_list_of_tuples()
  CPU times: user 0.93 s, sys: 0.08 s, total: 1.01 s
  Wall time: 0.98 s
  
  In [3]: %timeit res = get_list_of_tuples()
  1 loops, best of 3: 92.1 ms per loop
  </code></pre>
  
  <p>As you can see, the generation of this large list of tuples takes just below a second. timeit reports the execution time to be around 0.1 second. Why is there such a big difference in the two reports?</p>
  
  <p>(Tested on IPython 0.11, Python 2.6.5.)</p>