Python obtains the number of Windows CPUs

Recently, I used Python to write a script for controlling make compilation. To compile the system on Windows, I need to first obtain the number of CPUs and determine the-j parameter of the make command based on the number of CPUs. Baidu once did not find a clear description, and then found that there is an environment variable in Windws: NUMBER_OF_PROCESSORS OK, the problem is fixed, the Code is as follows:

Import OS cpu_num = '1' if 'Number _ OF_PROCESSORS 'in OS. environ: cpu_num = OS. environ ['Number _ OF_PROCESSORS '] print 'cpu _ num: % s' % cpu_num