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社区首页 >专栏 >python 基准测试(cProfile \ kcachegrind \ line_profiler \ memory_profiler)

python 基准测试(cProfile \ kcachegrind \ line_profiler \ memory_profiler)

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Michael阿明
发布2022-09-21 10:29:39
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发布2022-09-21 10:29:39
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learn from 《Python高性能(第2版)》

类似工具:pycharm profile对函数调用效率进行测试

1. 例子

一个圆周运动的动画

代码语言:javascript
复制
from matplotlib import pyplot as plt
from matplotlib import animation
from random import uniform
import timeit


class Particle:
    __slots__ = ('x', 'y', 'ang_speed')
    # 声明成员只允许这么多,不能动态添加,当生成大量实例时,可以减少内存占用

    def __init__(self, x, y, ang_speed):
        self.x = x
        self.y = y
        self.ang_speed = ang_speed


class ParticleSimulator:

    def __init__(self, particles):
        self.particles = particles

    def evolve(self, dt):
        timestep = 0.00001
        nsteps = int(dt / timestep)

        for i in range(nsteps):
            for p in self.particles:
                norm = (p.x ** 2 + p.y ** 2) ** 0.5
                v_x = (-p.y) / norm
                v_y = p.x / norm

                d_x = timestep * p.ang_speed * v_x
                d_y = timestep * p.ang_speed * v_y

                p.x += d_x
                p.y += d_y


def visualize(simulator):
    X = [p.x for p in simulator.particles]
    Y = [p.y for p in simulator.particles]

    fig = plt.figure()
    ax = plt.subplot(111, aspect='equal')
    line, = ax.plot(X, Y, 'ro')

    # Axis limits
    plt.xlim(-1, 1)
    plt.ylim(-1, 1)

    # It will be run when the animation starts
    def init():
        line.set_data([], [])
        return line,

    def animate(i):
        # We let the particle evolve for 0.1 time units
        simulator.evolve(0.01)
        X = [p.x for p in simulator.particles]
        Y = [p.y for p in simulator.particles]

        line.set_data(X, Y)
        return line,

    # Call the animate function each 10 ms
    anim = animation.FuncAnimation(fig,
                                   animate,
                                   init_func=init,
                                   blit=True,
                                   interval=10)
    plt.show()


def test_visualize():
    particles = [Particle(0.3, 0.5, +1),
                 Particle(0.0, -0.5, -1),
                 Particle(-0.1, -0.4, +3),
                 Particle(-0.2, -0.8, +3),]

    simulator = ParticleSimulator(particles)
    visualize(simulator)


if __name__ == '__main__':
    test_visualize()
在这里插入图片描述
在这里插入图片描述

2. 运行耗时测试

linux time 命令

代码语言:javascript
复制
def benchmark():
    particles = [Particle(uniform(-1.0, 1.0),
                          uniform(-1.0, 1.0),
                          uniform(-1.0, 1.0))
                  for i in range(100)]

    simulator = ParticleSimulator(particles)
    # visualize(simulator)
    simulator.evolve(0.1)

if __name__ == '__main__':
    benchmark()

生成100个实例,模拟 0.1 秒

在 linux 中进行测试耗时:

代码语言:javascript
复制
time python my.py
real    0m10.435s  # 进程实际花费时间
user    0m2.078s  # 计算期间 所有CPU花费总时间
sys     0m1.412s  #  执行系统相关任务(内存分配)期间,所有CPU花费总时间

python timeit包

  • 指定 循环次数、重复次数
代码语言:javascript
复制
def timing():
    result = timeit.timeit('benchmark()',
                           setup='from __main__ import benchmark',
                           number=10)
    # Result is the time it takes to run the whole loop
    print(result)

    result = timeit.repeat('benchmark()',
                           setup='from __main__ import benchmark',
                           number=10,
                           repeat=3)
    # Result is a list of times
    print(result)

输出:

代码语言:javascript
复制
6.9873279229996115
[6.382431660999828, 6.248147055000118, 6.325469069000064]

pytest、pytest-benchmark

代码语言:javascript
复制
pip install pytest
pip install pytest-benchmark
代码语言:javascript
复制
$ pytest test_simul.py::test_evolve
=================== test session starts ====================platform linux -- Python 3.8.10, pytest-7.1.2, pluggy-1.0.0
benchmark: 3.4.1 (defaults: timer=time.perf_counter disable_gc=False min_rounds=5 min_time=0.000005 max_time=1.0 calibration_precision=10 warmup=False warmup_iterations=100000)
rootdir: /mnt/d/gitcode/Python_learning/Python-High-Performance-Second-Edition-master/Chapter01
plugins: benchmark-3.4.1
collected 1 item

test_simul.py .                                      [100%]


---------------------------------------------- benchmark: 1 tests ---------------------------------------------
Name (time in ms)         Min      Max     Mean  StdDev   Median     IQR  Outliers      OPS  Rounds  Iterations
---------------------------------------------------------------------------------------------------------------
test_evolve           15.9304  42.7975  20.1502  5.6825  18.2795  3.7249       5;5  49.6274      58           1
---------------------------------------------------------------------------------------------------------------

Legend:
  Outliers: 1 Standard Deviation from Mean; 1.5 IQR (InterQuartile Range) from 1st Quartile and 3rd Quartile.
  OPS: Operations Per Second, computed as 1 / Mean

上面显示,测了58次,用时的最小、最大、均值、方差、中位数等

3. cProfile 找出瓶颈

  • profile包是 python写的开销比较大,cProfile 是C语言编写的,开销小
代码语言:javascript
复制
python -m cProfile simul.py
代码语言:javascript
复制
$ python -m cProfile simul.py
         2272804 function calls (2258641 primitive calls) in 8.209 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
       30    0.000    0.000    0.001    0.000 <__array_function__ internals>:177(any)
      160    0.000    0.000    0.002    0.000 <__array_function__ internals>:177(column_stack)
      161    0.000    0.000    0.004    0.000 <__array_function__ internals>:177(concatenate)
       34    0.000    0.000    0.000    0.000 <__array_function__ internals>:177(copyto)
       30    0.000    0.000    0.002    0.000 <__array_function__ internals>:177(linspace)
       30    0.000    0.000    0.000    0.000 <__array_function__ internals>:177(ndim)
       30    0.000    0.000    0.000    0.000 <__array_function__ internals>:177(result_type)
        5    0.000    0.000    0.116    0.023 <frozen importlib._bootstrap>:1002(_gcd_import)
   485/33    0.001    0.000    6.807    0.206 <frozen importlib._bootstrap>:1017(_handle_fromlist)
   。。。

输出结果非常长

tottime 排序 -s tottime,看前几个就是耗时最多的几个

代码语言:javascript
复制
$ python -m cProfile -s tottime simul.py
         2272784 function calls (2258621 primitive calls) in 7.866 seconds

   Ordered by: internal time

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
     1258    2.498    0.002    2.498    0.002 {built-in method posix.stat}
      273    1.057    0.004    1.057    0.004 {built-in method io.open_code}
       27    0.874    0.032    0.879    0.033 {built-in method _imp.create_dynamic}
        1    0.691    0.691    0.691    0.691 simul.py:21(evolve)
      273    0.464    0.002    0.464    0.002 {method 'read' of '_io.BufferedReader' objects}
      273    0.432    0.002    1.953    0.007 <frozen importlib._bootstrap_external>:1034(get_data)
    32045    0.245    0.000    0.411    0.000 inspect.py:625(cleandoc)
       30    0.171    0.006    0.171    0.006 {built-in method posix.listdir}
       33    0.151    0.005    0.151    0.005 {built-in method io.open}

或者使用代码

代码语言:javascript
复制
>>> from simul import benchmark
>>> import cProfile
>>> cProfile.run('benchmark()')
                  707 function calls in 0.733 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    0.733    0.733 <string>:1(<module>)
      300    0.000    0.000    0.000    0.000 random.py:415(uniform)
      100    0.000    0.000    0.000    0.000 simul.py:10(__init__)
        1    0.000    0.000    0.733    0.733 simul.py:117(benchmark)
        1    0.000    0.000    0.000    0.000 simul.py:118(<listcomp>)
        1    0.000    0.000    0.000    0.000 simul.py:18(__init__)
        1    0.733    0.733    0.733    0.733 simul.py:21(evolve)
        1    0.000    0.000    0.733    0.733 {built-in method builtins.exec}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
      300    0.000    0.000    0.000    0.000 {method 'random' of '_random.Random' objects}

profile 对象开启和关闭之间可以包含任意代码

代码语言:javascript
复制
>>> from simul import benchmark
>>> import cProfile
>>>
>>> pr = cProfile.Profile()
>>> pr.enable()
>>> benchmark()
>>> pr.disable()
>>> pr.print_stats()
         706 function calls in 0.599 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    0.000    0.000 <stdin>:1(<module>)
      300    0.000    0.000    0.000    0.000 random.py:415(uniform)
      100    0.000    0.000    0.000    0.000 simul.py:10(__init__)
        1    0.000    0.000    0.599    0.599 simul.py:117(benchmark)
        1    0.000    0.000    0.000    0.000 simul.py:118(<listcomp>)
        1    0.000    0.000    0.000    0.000 simul.py:18(__init__)
        1    0.599    0.599    0.599    0.599 simul.py:21(evolve)
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
      300    0.000    0.000    0.000    0.000 {method 'random' of '_random.Random' objects}
  • tottime 不含调用其他函数的时间,cumtime 执行函数(包含调用其他函数的时间)的总时间

KCachegrind 图形化分析

KCachegrind - pyprof2calltree - cProfile

代码语言:javascript
复制
sudo apt install kcachegrind
pip install pyprof2calltree
代码语言:javascript
复制
python -m cProfile -o prof.out taylor.py
pyprof2calltree -i prof.out -o prof.calltree
代码语言:javascript
复制
kcachegrind prof.calltree

安装 kcachegrind 失败,没有运行截图

还有其他工具 Gprof2Dot 可以生成调用图

4. line_profiler

它是一个 py 包,安装后,对要监视的函数应用 装饰器 @profile

代码语言:javascript
复制
pip install line_profiler

https://github.com/rkern/line_profiler

代码语言:javascript
复制
kernprof -l -v simul.py
代码语言:javascript
复制
$ kernprof -l -v simul.py
Wrote profile results to simul.py.lprof
Timer unit: 1e-06 s

Total time: 4.39747 s
File: simul.py
Function: evolve at line 21

Line #      Hits         Time  Per Hit   % Time  Line Contents
==============================================================
    21                                               @profile
    22                                               def evolve(self, dt):
    23         1          5.0      5.0      0.0          timestep = 0.00001
    24         1          5.0      5.0      0.0          nsteps = int(dt/timestep)
    25
    26     10001       5419.0      0.5      0.1          for i in range(nsteps):
    27   1010000     454924.0      0.5     10.3              for p in self.particles:
    28
    29   1000000     791441.0      0.8     18.0                  norm = (p.x**2 + p.y**2)**0.5
    30   1000000     537019.0      0.5     12.2                  v_x = (-p.y)/norm
    31   1000000     492304.0      0.5     11.2                  v_y = p.x/norm
    32
    33   1000000     525471.0      0.5     11.9                  d_x = timestep * p.ang_speed * v_x
    34   1000000     521829.0      0.5     11.9                  d_y = timestep * p.ang_speed * v_y
    35
    36   1000000     537637.0      0.5     12.2                  p.x += d_x
    37   1000000     531418.0      0.5     12.1                  p.y += d_y
代码语言:javascript
复制
python -m line_profiler simul.py.lprof
代码语言:javascript
复制
$ python -m line_profiler simul.py.lprof
Timer unit: 1e-06 s

Total time: 5.34553 s
File: simul.py
Function: evolve at line 21

Line #      Hits         Time  Per Hit   % Time  Line Contents
==============================================================
    21                                               @profile
    22                                               def evolve(self, dt):
    23         1          3.0      3.0      0.0          timestep = 0.00001
    24         1          3.0      3.0      0.0          nsteps = int(dt/timestep)
    25
    26     10001       6837.0      0.7      0.1          for i in range(nsteps):
    27   1010000     567894.0      0.6     10.6              for p in self.particles:
    28
    29   1000000     953363.0      1.0     17.8                  norm = (p.x**2 + p.y**2)**0.5
    30   1000000     656821.0      0.7     12.3                  v_x = (-p.y)/norm
    31   1000000     601929.0      0.6     11.3                  v_y = p.x/norm
    32
    33   1000000     635255.0      0.6     11.9                  d_x = timestep * p.ang_speed * v_x
    34   1000000     636091.0      0.6     11.9                  d_y = timestep * p.ang_speed * v_y
    35
    36   1000000     651873.0      0.7     12.2                  p.x += d_x
    37   1000000     635462.0      0.6     11.9                  p.y += d_y

5. 性能优化

  • 用更简洁的计算公式
  • 预计算不变量
  • 减少赋值语句,消除中间变量

注意:细微的优化,速度有所提高,但可能并不显著,还需要保证算法正确

6. dis 模块

该包可以了解代码是如何转换为字节码的, dis 表示 disassemble 反汇编

代码语言:javascript
复制
import dis
dis.dis(函数名)
代码语言:javascript
复制
dis.dis(ParticleSimulator.evolve)
 22           0 LOAD_CONST               1 (1e-05)
              2 STORE_FAST               2 (timestep)

 23           4 LOAD_GLOBAL              0 (int)
              6 LOAD_FAST                1 (dt)
              8 LOAD_FAST                2 (timestep)
             10 BINARY_TRUE_DIVIDE
             12 CALL_FUNCTION            1
             14 STORE_FAST               3 (nsteps)

 25          16 LOAD_GLOBAL              1 (range)
             18 LOAD_FAST                3 (nsteps)
             20 CALL_FUNCTION            1
             22 GET_ITER
        >>   24 FOR_ITER               118 (to 144)
             26 STORE_FAST               4 (i)

 26          28 LOAD_FAST                0 (self)
             30 LOAD_ATTR                2 (particles)
             32 GET_ITER
        >>   34 FOR_ITER               106 (to 142)
             36 STORE_FAST               5 (p)

 28          38 LOAD_FAST                5 (p)
             40 LOAD_ATTR                3 (x)
             42 LOAD_CONST               2 (2)
             44 BINARY_POWER
             46 LOAD_FAST                5 (p)
             48 LOAD_ATTR                4 (y)
             50 LOAD_CONST               2 (2)
             52 BINARY_POWER
             54 BINARY_ADD
             56 LOAD_CONST               3 (0.5)
             58 BINARY_POWER
             60 STORE_FAST               6 (norm)

 29          62 LOAD_FAST                5 (p)
             64 LOAD_ATTR                4 (y)
             66 UNARY_NEGATIVE
             68 LOAD_FAST                6 (norm)
             70 BINARY_TRUE_DIVIDE
             72 STORE_FAST               7 (v_x)

 30          74 LOAD_FAST                5 (p)
             76 LOAD_ATTR                3 (x)
             78 LOAD_FAST                6 (norm)
             80 BINARY_TRUE_DIVIDE
             82 STORE_FAST               8 (v_y)

 32          84 LOAD_FAST                2 (timestep)
             86 LOAD_FAST                5 (p)
             88 LOAD_ATTR                5 (ang_speed)
             90 BINARY_MULTIPLY
             92 LOAD_FAST                7 (v_x)
             94 BINARY_MULTIPLY
             96 STORE_FAST               9 (d_x)

 33          98 LOAD_FAST                2 (timestep)
            100 LOAD_FAST                5 (p)
            102 LOAD_ATTR                5 (ang_speed)
            104 BINARY_MULTIPLY
            106 LOAD_FAST                8 (v_y)
            108 BINARY_MULTIPLY
            110 STORE_FAST              10 (d_y)

 35         112 LOAD_FAST                5 (p)
            114 DUP_TOP
            116 LOAD_ATTR                3 (x)
            118 LOAD_FAST                9 (d_x)
            120 INPLACE_ADD
            122 ROT_TWO
            124 STORE_ATTR               3 (x)

 36         126 LOAD_FAST                5 (p)
            128 DUP_TOP
            130 LOAD_ATTR                4 (y)
            132 LOAD_FAST               10 (d_y)
            134 INPLACE_ADD
            136 ROT_TWO
            138 STORE_ATTR               4 (y)
            140 JUMP_ABSOLUTE           34
        >>  142 JUMP_ABSOLUTE           24
        >>  144 LOAD_CONST               0 (None)
            146 RETURN_VALUE

可以是用该工具了解指令的多少和代码是如何转换的

7. memory_profiler

https://pypi.org/project/memory-profiler/

代码语言:javascript
复制
pip install memory_profiler
pip install psutil

psutil说明

也需要对监视的函数 加装饰器 @profile

代码语言:javascript
复制
python -m memory_profiler simul.py
代码语言:javascript
复制
$ python -m memory_profiler simul.py
Filename: simul.py

Line #    Mem usage    Increment  Occurrences   Line Contents
=============================================================
   141   67.465 MiB   67.465 MiB           1   @profile
   142                                         def benchmark_memory():
   143   84.023 MiB   16.559 MiB      300004       particles = [Particle(uniform(-1.0, 1.0),
   144   84.023 MiB    0.000 MiB      100000                             uniform(-1.0, 1.0),
   145   84.023 MiB    0.000 MiB      100000                             uniform(-1.0, 1.0))
   146   84.023 MiB    0.000 MiB      100001                     for i in range(100000)]
   147
   148   84.023 MiB    0.000 MiB           1       simulator = ParticleSimulator(particles)
   149   84.023 MiB    0.000 MiB           1       simulator.evolve(0.001)

内存使用随时间的变化

代码语言:javascript
复制
$ mprof run simul.py
mprof: Sampling memory every 0.1s
running new process
running as a Python program...

绘制曲线

代码语言:javascript
复制
$ mprof plot
在这里插入图片描述
在这里插入图片描述
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目录
  • 1. 例子
  • 2. 运行耗时测试
    • linux time 命令
      • python timeit包
        • pytest、pytest-benchmark
        • 3. cProfile 找出瓶颈
          • KCachegrind 图形化分析
          • 4. line_profiler
          • 5. 性能优化
          • 6. dis 模块
          • 7. memory_profiler
          领券
          问题归档专栏文章快讯文章归档关键词归档开发者手册归档开发者手册 Section 归档