Python Scripting Performance analysis

From: http://www.cnblogs.com/btchenguang/archive/2012/02/03/2337112.html

deffoo (): Sum=0 forIinchRange (10000): Sum+=I SumA=Bar () Sumb=Bar ()returnsumdefbar (): Sum=0 forIinchRange (100000): Sum+=Ireturnsumif __name__=="__main__":    ImportCProfile#Print analysis results directly to the consoleCprofile.run ("foo ()")    #Save the results of the analysis to a file, but the content is poor readability ... Need to invoke Pstats module analysis resultsCprofile.run ("foo ()","result")    #You can also work directly with the command line    #>python-m cProfile myscript.py-o result         Importpstats#Create a Stats objectp = pstats. Stats ("result")    #The effect of this line is the same as the direct run Cprofile.run ("foo ()").P.strip_dirs (). Sort_stats (-1). Print_stats ()#strip_dirs (): Remove extraneous path information from all module names    #sort_stats (): Sort the printed information according to the standard module/name/line string    #print_stats (): Print out all analysis information     #Sort by Function nameP.strip_dirs (). Sort_stats ("name"). Print_stats ()#Sort by the run time accumulated in a function    #Print_stats (3): Prints only the first 3 lines of function information, the parameter can also be a decimal, representing the first few percent of the function informationP.strip_dirs (). Sort_stats ("Cumulative"). Print_stats (3)     #there is another way to useP.sort_stats (' Time','cum'). Print_stats (. 5,'Foo')    #Sort by time, then by cumulative, and then down to the first 50% with function information     #If you want to know which functions call bar, you can use theP.print_callers (0.5,"Bar")     #Similarly, see which functions are called in the Foo () functionP.print_callees ("Foo")

Run: python-m cProfile t12.py, print result:

The specific explanations for each column of the output are as follows: (http://xianglong.me/article/analysis-python-application-performance-using-cProfile/)

ncalls: Indicates the number of times the function was called;

tottime: Indicates the total elapsed time of the specified function, and removes the run time of the calling child function in the function;

Percall: (the first percall) equals tottime/ncalls;

Cumtime: Represents the time that the call to the function and all its child functions runs, that is, when the function starts calling to the return time;

Percall: (the second percall) is the average time that a function is run, equal to Cumtime/ncalls;

Filename:lineno (function): The specific information of each function call;

In addition, in the analysis above, the sorting method uses the function call time (cumulative), in addition to this there are some other allowable sorting methods:calls, cumulative, file, line, module, name, NFL, pcalls, stdname, time, etc.

# 增加排序方式

python -m cProfile -s cumulative  t2 .py #按照cumulative排序

Python Scripting Performance analysis