virtualenvwrapper.sh报错: There was a problem running the initialization hooks.解决

由于在ubuntu环境下，将python做与python3.6做了软链接(ln -s python python3.6)，并且pip也被我做了软链接，所以导致用pip安装virtualenvwrapper之后，在source启动virtualenvwrapper.sh时以及workon 虚拟环境时总是报错：

./virtualenvwrapper.sh: line 230: : command not found
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= and that PATH is
set properly.

这是根据提示230行的语句：

"$VIRTUALENVWRAPPER_PYTHON" -m 'virtualenvwrapper.hook_loader' \

结合错误信息与提示找到的语句，猜测应该是VIRTUALENVWRAPPER_PYTHON这里有问题，然后在virtualenvwrapper.sh文件中查找VIRTUALENVWRAPPER_PYTHON，发现了关键点：

# Locate the global Python where virtualenvwrapper is installed.
if [ "${VIRTUALENVWRAPPER_PYTHON:-}" = "" ]
then
    VIRTUALENVWRAPPER_PYTHON="$(command \which python3)"    # 原本是写的\which python，这里贴出来的是我修改为python3后的。
fi

VIRTUALENVWRAPPER_PYTHON是用来(Locate the global Python where virtualenvwrapper is installed.)定位哪个python下面安装了virtualenvwrapper的。原本指定的位置是python，也就是2.7版本的。鉴于之前我使用python3.6安装的，所以此处要改成python3。然后这个错误就消失了。

使用virtualenvwrapper的好处是不用每次使用source /xxx/虚拟环境/bin/activate来启动虚拟环境了，在~/.bashrc配置一下，日后开启虚拟环境直接可以用workon命令即可，具体操作步骤，前提是你已经安装了python-virtualenv了：

# Setup:
#  1. Create a directory to hold the virtual environments.
#     (mkdir $HOME/.virtualenvs).
#  2. Add a line like "export WORKON_HOME=$HOME/.virtualenvs"
#     to your .bashrc.
#  3. Add a line like "source /path/to/this/file/virtualenvwrapper.sh"
#     to your .bashrc.
#  4. Run: source ~/.bashrc
#  5. Run: workon
#  6. A list of environments, empty, is printed.
#  7. Run: mkvirtualenv temp
#  8. Run: workon
#  9. This time, the "temp" environment is included.
# 10. Run: workon temp
# 11. The virtual environment is activated.