安装virtualenv和virtualenvwrapper

根据 这篇文章, 学习flask前要先装一下virtualenv

安装virtualenv和virtualenvwrapper

sudo pip install virtualenv
sudo pip install virtualenvwrapper

安装后还不能使用, 默认virtualenvwrapper安装在/usr/local/bin下, 打开下面的 virtualenvwrapper.sh, 会看到Setup,内容如下:

 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.

如果碰到权限问题,可以看这个答案:http://stackoverflow.com/questions/21194519/cant-use-mkvirtualenv-site-packages-markerlib-permission-denied

需要执行

sudo chown -R your-username:wheel /Library/Python/2.7/site-packages

执行一下在虚拟环境下执行pip --version, 看看pip所在的目录是不是虚拟环境的目录,如果不是,在.bashrc中加入如下:

# pip should only run if there is a virtualenv currently activated
export PIP_REQUIRE_VIRTUALENV=true
# cache pip-installed packages to avoid re-downloading
export PIP_DOWNLOAD_CACHE=$HOME/.pip/cache

具体的使用可以看:http://liuzhijun.iteye.com/blog/1872241