Python: iterating over list vs over dict items efficiency

Question

Is iterating over some_dict.items() as efficient as iterating over a list of the same items in CPython?

Answer 1

Although iterating through some_list is 2x speedup than some_dict.items(), but iterating through some_list by index is almost as same as iterating through some_dict by key.

K = 1000000
some_dict = dict(zip(xrange(K), reversed(xrange(K))))
some_list = zip(xrange(K), xrange(K))
%timeit for t in some_list: t
10 loops, best of 3: 55.7 ms per loop
%timeit for i in xrange(len(some_list)):some_list[i]
10 loops, best of 3: 94 ms per loop
%timeit for key in some_dict: some_dict[key]
10 loops, best of 3: 115 ms per loop
%timeit for i,t in enumerate(some_list): t
10 loops, best of 3: 103 ms per loop