解决pip3 install waring ‘The script xxx is installed in ‘/home/xxx/bin‘ which is not on PATH‘
解决办法：
echo 'export PATH=/home/xxx/bin:$PATH' >>~/.bashrc
source ~/.bashrc
其中“/home/xxx/bin”为WARNING提示的PATH
然后卸载掉刚才安装的包，并重新安装：
pip3 uninstall virtualenv
pip3 install virtualenv