ubuntu14安裝python3後，打開命令行界面總會提示：
/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.
有的文章說修改.bashrc中的VIRTUALENVWRAPPER_PYTHON，之後執行source .bashrc。這個方法對我本機沒有起作用
之後查詢：
http://www.itkeyword.com/doc/1445534594720488x414/usr-bin-python3-error-while-finding-spec-for-virtualenvwrapper-hook-loader
$ sudo pip3 install virtualenv virtualenvwrapper
$ source .bashrc
然後就沒有提示了