dict() vs. {}

gistfile1.sh

$ python2.7 -m timeit -n 1000000 -r 5 -v 'd=dict();d["a"]="b"'
raw times: 0.182 0.179 0.179 0.18 0.179
1000000 loops, best of 5: 0.179 usec per loop

$ python2.7 -m timeit -n 1000000 -r 5 -v 'd={};d["a"]="b"'
raw times: 0.0863 0.0859 0.0858 0.0882 0.0877
1000000 loops, best of 5: 0.0858 usec per loop


gokmen@rodosto % python3.3 -m timeit -n 1000000 -r 5 -v 'd=dict();d["a"]="b"'
raw times: 0.396 0.376 0.359 0.361 0.362
1000000 loops, best of 5: 0.359 usec per loop

gokmen@rodosto % python3.3 -m timeit -n 1000000 -r 5 -v 'd={};d["a"]="b"'
raw times: 0.196 0.183 0.186 0.189 0.185
1000000 loops, best of 5: 0.183 usec per loop

gokmen@rodosto % python2.7 -m timeit -n 1000000 -r 5 -v 'd=dict();d["a"]="b"'
raw times: 0.411 0.398 0.396 0.408 0.401
1000000 loops, best of 5: 0.396 usec per loop

gokmen@rodosto % python2.7 -m timeit -n 1000000 -r 5 -v 'd={};d["a"]="b"' 
raw times: 0.146 0.139 0.138 0.14 0.143
1000000 loops, best of 5: 0.138 usec per loop