不仅是del
更容易理解,但似乎比pop() http://docs.python.org/library/stdtypes.html#dict.pop:
$ python -m timeit -s "d = {'f':1,'foo':2,'bar':3}" "for k in d.keys():" " if k.startswith('f'):" " del d[k]"
1000000 loops, best of 3: 0.733 usec per loop
$ python -m timeit -s "d = {'f':1,'foo':2,'bar':3}" "for k in d.keys():" " if k.startswith('f'):" " d.pop(k)"
1000000 loops, best of 3: 0.742 usec per loop
编辑:感谢 Alex Martelli 提供有关如何进行基准测试的说明。希望我没有在任何地方犯错。
首先测量复制所需的时间:
$ python -m timeit -s "d = {'f':1,'foo':2,'bar':3}" "d1 = d.copy()"
1000000 loops, best of 3: 0.278 usec per loop
复制字典的基准:
$ python -m timeit -s "d = {'f':1,'foo':2,'bar':3}" "d1 = d.copy()" "for k in d1.keys():" " if k.startswith('f'):" " del d1[k]"
100000 loops, best of 3: 1.95 usec per loop
$ python -m timeit -s "d = {'f':1,'foo':2,'bar':3}" "d1 = d.copy()" "for k in d1.keys():" " if k.startswith('f'):" " d1.pop(k)"
100000 loops, best of 3: 2.15 usec per loop
减去复制成本,我们得到 1.872 usecpop()
1.672 为del
.