apt-get install python3-pip　　　　# Python3

➜  ~ pip3 -V                                             
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)

pip3 install flake8

执行目录的flake检测

python2.7 -m flake8 cinder  # 2.7

python3.6 -m flake8 cinder # 3.6