Zitat von Chris Withers <ch...@simplistix.co.uk>:
$ python2.7 -m timeit -n 1000000 -r 5 -v
"{'a':1,'b':2,'c':3,'d':4,'e':5,'f':6,'g':7}"
raw times: 1.49 1.49 1.5 1.49 1.48
1000000 loops, best of 5: 1.48 usec per loop
$ python2.7 -m timeit -n 1000000 -r 5 -v 'dict(a=1,b=2,c=3,d=4,e=5,f=6,g=7)'
raw times: 2.35 2.36 2.41 2.42 2.35
1000000 loops, best of 5: 2.35 usec per loop
$ python2.7 -m timeit -n 1000000 -r 5 -v 'def md(**kw): return kw;
md(a=1,b=2,c=3,d=4,e=5,f=6,g=7)'
raw times: 0.507 0.515 0.516 0.529 0.524
1000000 loops, best of 5: 0.507 usec per loop
For the naive observer (ie: me!), why is that?
It's faster than calling dict() because the dict code will
create a second dictionary, and discard the keywords dictionary.
It's (probably) faster than the dictionary display, because
the {} byte code builds the dictionary one-by-one, whereas
the keywords dictionary is built in a single step (taking
all keys and values from the evaluation stack).
Regards,
Martin
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