python3 - 哪个执行起来更快 - 按顺序弹出还是按列表理解?

python3 - Which one will be faster to execute - pop in sequence or in list comprehension?

考虑以下两段从字典中弹出键的代码:

  1. 没有列表理解
    d = {'a': 1, 'b': 2, 'c': 3}   
    d.pop('a')
    d.pop('b')
  1. 具有列表理解
    d = {'a': 1, 'b': 2, 'c': 3}
    [d.pop(key) for key in ['a', 'b']]

哪个会更快,为什么?

import timeit
code_to_test1 =  """d = {'a': 1, 'b': 2, 'c': 3}   
d.pop('a')
d.pop('b')"""
code_to_test2 =  """d = {'a': 1, 'b': 2, 'c': 3}
[d.pop(key) for key in ['a', 'b']]"""
elapsed_time1 = timeit.timeit(code_to_test1, number=5000)
elapsed_time2 = timeit.timeit(code_to_test2, number=5000)
print(elapsed_time1,elapsed_time2)

输出:

0.0008224000000000009 0.0017937999999999982
0.000853600000000003 0.0018411999999999942
0.0008063000000000028 0.002663699999999998

如您所见,第一个代码比第二个代码快,因为在第二个代码中,您在列表中进行迭代。