AttributeError: module 'subprocess' has no attribute 'mswindows'

subprocess.mswindows

python2可以使用

>>> import subprocess
>>> IS_WIN = subprocess.mswindows
>>> IS_WIN
False

Python3

python3.5把mswindows改名_mswindows了。

>>> IS_WIN = subprocess._mswindows
>>> IS_WIN
False

参考

Python 3.5 renames subprocess.mswindows #18

https://github.com/PySide/pyside-setup/issues/53