>>> timeit('for i in {1: 5}.iteritems(): pass')
0.2221989631652832
>>> timeit('for i in {1: 5}.viewitems(): pass')
0.25026607513427734
>>> timeit('for i in {1: 5}.items(): pass')
0.258465051651001

>>> timeit('for i in {1: 5}.iterkeys(): pass')
0.19254398345947266
>>> timeit('for i in {1: 5}.viewkeys(): pass')
0.2200300693511963
>>> timeit('for i in {1: 5}.keys(): pass')
0.24395108222961426