分析python代码性能的程序分析包cProfile

最新推荐文章于 2025-11-24 15:28:47 发布

原创最新推荐文章于 2025-11-24 15:28:47 发布 · 72 阅读

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#python #前端 #javascript #开发语言 #ecmascript

本文通过对比三段Python代码的运行效率，深入分析了不同算法在处理大量随机数时的时间消耗。实验使用cProfile模块进行性能剖析，揭示了排序与筛选操作的不同组合对整体性能的影响。

方法:

def f1(lIn):
    l1 = sorted(lIn)
    l2 = [i for i in l1 if i<0.5]
    return [i*i for i in l2]
def f2(lIn):
    l1 = [i for i in lIn if i<0.5]
    l2 = sorted(l1)
    return [i*i for i in l2]
def f3(lIn):
    l1 = [i*i for i in lIn]
    l2 = sorted(l1)
    return [i for i in l1 if i<(0.5*0.5)]

import random
import cProfile
lIn = [random.random() for i in range(100000)]
cProfile.run('f1(lIn)')
cProfile.run('f2(lIn)')
cProfile.run('f3(lIn)')

结果:

D:\Python\Python38\python.exe D:/python_learn/lambda_test/test.py
         7 function calls in 0.036 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.002    0.002    0.036    0.036 <string>:1(<module>)
        1    0.000    0.000    0.034    0.034 test.py:118(f1)
        1    0.011    0.011    0.011    0.011 test.py:120(<listcomp>)
        1    0.006    0.006    0.006    0.006 test.py:121(<listcomp>)
        1    0.000    0.000    0.036    0.036 {built-in method builtins.exec}
        1    0.017    0.017    0.017    0.017 {built-in method builtins.sorted}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}


         7 function calls in 0.018 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.001    0.001    0.018    0.018 <string>:1(<module>)
        1    0.000    0.000    0.017    0.017 test.py:122(f2)
        1    0.005    0.005    0.005    0.005 test.py:123(<listcomp>)
        1    0.003    0.003    0.003    0.003 test.py:125(<listcomp>)
        1    0.000    0.000    0.018    0.018 {built-in method builtins.exec}
        1    0.008    0.008    0.008    0.008 {built-in method builtins.sorted}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}


         7 function calls in 0.031 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.003    0.003    0.031    0.031 <string>:1(<module>)
        1    0.000    0.000    0.029    0.029 test.py:126(f3)
        1    0.007    0.007    0.007    0.007 test.py:127(<listcomp>)
        1    0.005    0.005    0.005    0.005 test.py:129(<listcomp>)
        1    0.000    0.000    0.031    0.031 {built-in method builtins.exec}
        1    0.017    0.017    0.017    0.017 {built-in method builtins.sorted}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}



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