Python 3.6.0: 'os' module does not have 'sched_getaffinity' method

问题

I am trying to check the number of cores my script is using with 'os.sched_getaffinity' method as suggested in Why does multiprocessing use only a single core after I import numpy?. But when I run

import os
os.sched_getaffinity(0)

I get

AttributeError                            
Traceback (most recent call last) <ipython-input-1-895d9c252fd1> in <module>()
1 import os
----> 2 os.sched_getaffinity(0)
AttributeError: module 'os' has no attribute 'sched_getaffinity'

What is going wrong here? Other standard methods from the 'os' module seems to work. I am running Anaconda 4.3.0 with Python 3.6.0. I tried on both Mac and Linux. Any alternative ways to check and change the task affinity?

回答1:

The docs say "They are only available on some Unix platforms." I guess your platform isn't one of the supported ones for these set of functions. You can check what's provided by typing

>>> import os
>>> print(dir(os))

The function does exist on my Debian Linux box, but it is absent on Windows and OSX as well. I don't know why it's not there on your Linux box. Perhaps your Linux is too old?

Also a simple google for "python process affinity" gives several alternatives

来源：https://stackoverflow.com/questions/42538153/python-3-6-0-os-module-does-not-have-sched-getaffinity-method