进口cProfile

Question

我目前正在学习如何使用cProfile，我有一些疑问。

我目前正在尝试分析以下脚本：

import time

def fast():
    print("Fast!")

def slow():
    time.sleep(3)
    print("Slow!")

def medium():
    time.sleep(0.5)
    print("Medium!")

fast()
slow()
medium()

我执行命令python -m cProfile test_cprofile.py并得到以下结果：

Fast!
Slow!
Medium!
     7 function calls in 3.504 seconds

Ordered by: standard name

ncalls  tottime  percall  cumtime  percall filename:lineno(function)
    1    0.000    0.000    3.504    3.504 test_cprofile.py:1(<module>)
    1    0.000    0.000    0.501    0.501 test_cprofile.py:10(medium)
    1    0.000    0.000    0.000    0.000 test_cprofile.py:3(fast)
    1    0.000    0.000    3.003    3.003 test_cprofile.py:6(slow)
    1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
    2    3.504    1.752    3.504    1.752 {time.sleep}

但是，当我使用pylab导入(例如，顶部的import pylab)编辑脚本时，cProfile的输出非常大。我试图使用python -m cProfile test_cprofile.py | head -n 10限制行数，但是收到以下错误：

Traceback (most recent call last):
File "/home/user/anaconda/lib/python2.7/runpy.py", line 162, in _run_module_as_main
"__main__", fname, loader, pkg_name)
File "/home/user/anaconda/lib/python2.7/runpy.py", line 72, in _run_code
exec code in run_globals
File "/home/user/anaconda/lib/python2.7/cProfile.py", line 199, in <module>
main()
File "/home/user/anaconda/lib/python2.7/cProfile.py", line 192, in main
runctx(code, globs, None, options.outfile, options.sort)
File "/home/user/anaconda/lib/python2.7/cProfile.py", line 56, in runctx
result = prof.print_stats(sort)
File "/home/user/anaconda/lib/python2.7/cProfile.py", line 81, in print_stats
pstats.Stats(self).strip_dirs().sort_stats(sort).print_stats()
File "/home/user/anaconda/lib/python2.7/pstats.py", line 360, in print_stats
self.print_line(func)
File "/home/user/anaconda/lib/python2.7/pstats.py", line 438, in print_line
print >> self.stream, c.rjust(9),
IOError: [Errno 32] Broken pipe

如果我们有一个import pylab或另一个模块在cProfile上生成如此高的输出信息，那么在类似的情况下，有人能帮助正确的过程吗？

Answer 1

如果您稍微修改了脚本，那么在不分析导入的情况下对脚本进行概要分析就会容易得多。

test_cprofiler.py

import time
import pylab

def fast():
    print("Fast!")

def slow():
    time.sleep(3)
    print("Slow!")

def medium():
    time.sleep(0.5)
    print("Medium!")

def main():
    fast()
    slow()
    medium()

if __name__ == "__main__":
    main()

profiler.py

import cProfile

import test_cprofiler

cProfile.run("test_cprofiler.main()")

以下列方式运行：

python profiler.py

它产生以下输出：

Fast!
Slow!
Medium!
         8 function calls in 3.498 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    3.498    3.498 <string>:1(<module>)
        1    0.000    0.000    2.998    2.998 run.py:11(slow)
        1    0.000    0.000    3.498    3.498 run.py:15(main)
        1    0.000    0.000    0.000    0.000 run.py:4(fast)
        1    0.000    0.000    0.500    0.500 run.py:7(medium)
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
        2    3.498    1.749    3.498    1.749 {time.sleep}