简述

virtaulenvwrapper是virtualenv的扩展包，可以更方便地新增，删除，复制，切换虚拟环境。
官方说明：https://bitbucket.org/dhellmann/virtualenvwrapper/src/master/README.txt

..   -*- mode: rst -*-

#################
virtualenvwrapper
#################

virtualenvwrapper is a set of extensions to Ian Bicking's `virtualenv
<http://pypi.python.org/pypi/virtualenv>`_ tool.  The extensions include
wrappers for creating and deleting virtual environments and otherwise
managing your development workflow, making it easier to work on more
than one project at a time without introducing conflicts in their
dependencies.

**Warning:** The 4.x release includes some potentially incompatible
changes for extensions from 3.x. The python modules for extensions are
now *always* run with ``PWD=$WORKON_HOME`` (previously the value of
PWD varied depending on the hook). The *shell* portion of any hook
(anything sourced by the user's shell when the hook is run) is still
run in the same place as before.

========
Features
========

1.  Organizes all of your virtual environments in one place.

2.  Wrappers for creating, copying and deleting environments, including
    user-configurable hooks.

3.  Use a single command to switch between environments.

4.  Tab completion for commands that take a virtual environment as
    argument.

5. User-configurable hooks for all operations.

6. Plugin system for more creating sharable extensions.

Rich Leland has created a short `screencast
<http://mathematism.com/2009/07/30/presentation-pip-and-virtualenv/>`__
showing off the features of virtualenvwrapper.

============
Installation
============

See the `project documentation
<http://www.doughellmann.com/docs/virtualenvwrapper/>`__ for
installation and setup instructions.

===============
Python Versions
===============

virtualenvwrapper is tested under Python 2.6 - 3.6.

===============
Shell Aliases
=============

Since virtualenvwrapper is largely a shell script, it uses shell
commands for a lot of its actions.  If your environment makes heavy
use of shell aliases or other customizations, you may encounter
issues.  Before reporting bugs in the bug tracker, please test
*without* your aliases enabled.  If you can identify the alias causing
the problem, that will help make virtualenvwrapper more robust.

virtualenvwrapper的使用方法

Setup:

 1. Create a directory to hold the virtual environments.
    (mkdir $HOME/.virtualenvs).
创建一个文件夹叫做`.virtualenvs`用来存放所有的虚拟环境，即以后创建的所有虚拟环境都会放在一个文件夹里
 2. Add a line like "export WORKON_HOME=$HOME/.virtualenvs"
    to your .bashrc.
将刚才创建的文件夹加入到系统的环境变量中
 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.