报错：/usr/bin/python: Error while finding module specification for ‘virtualenvwrapper.hook_loader‘

ubuntu16.04 安装python3.7后
打开命令行总是报错:
/usr/bin/python: Error while finding module specification for ‘virtualenvwrapper.hook_loader’ (ModuleNotFoundError: No module named ‘virtualenvwrapper’)
virtualenvwrapper.sh: There was a problem running the initialization hooks.

If Python could not import the module virtualenvwrapper.hook_loader,
check that virtualenvwrapper has been installed for
VIRTUALENVWRAPPER_PYTHON=/usr/bin/python and that PATH is
set properly.

解决办法:
$ sudo pip3 install virtualenv virtualenvwrapper
$ source .bashrc

过程中可能报错:
升级pip
sudo pip3 install --upgrade pip -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com