Python: exe file from script, significant performance decrese

I am testing a C++ code compiled to exe (O errors, 0 warnings). The code represents a console application. I run the apllication in the following ways:

a) from the windows7 command line: average time 497sec

b) from Python script using

subprocess.call ()

with the average time 1201 开发者_如何学Pythonsec!

Results:

The application runs almost 3 tines longer from Python script than from command line... Is this significant performance decrease normal ?

Are you measuring from the point that subprocess.call() is executed or from the point that you load the Python script? I would imagine that a large portion of that time arises from waiting for the Python interpreter to load, the subprocess module to load, any other modules you import, etc. If your Python script which calls the program will end up being large then I think this will become insignificant. If it will be short, you may be better off creating a Windows batch (.bat) file to call the program (assuming those still exist in Win7...I haven't used Windows in a while).