"Python Tools" virtualenv and Virtualenvwrapper__python

Introduction to Virtualenv and Virtualenvwrapper

The Virtualenv tool can create isolated python environments
We often encounter two FAQ versions that rely on the indirect license

Version dependencies:
1. If you have an app that requires a library of Libfoo 1.0, and another app that requires Libfoo 2.0 libraries, how can you install both libraries to/usr/lib/python2.7/site-packages?
2. When the library of the system has changed, perhaps the app can not run
Indirect license
3. When the host, we do not have root permissions.

Virtualenv can solve such a problem, it will create a separate environment, the library will be installed in its own directory, will not be shared with other environments.

Because Virtualenv is a bit troublesome to use, wrapper encapsulates it to make it better, and eventually we use the wrapper-provided command, but the actual work is done by virtualenv. installation

It is recommended to use PIP installation

Pip Install virutalenv Virtualenvwrapper

virtualenv Usage Creating an environment

virtualenv [Virtual Environment name] 
virtualenv test

The default created environment is that you can use a package that the system has installed.

If you do not want to use the system's package, plus the –no-site-packeages parameter

Virtualenv--no-site-packages Test

This time will create the directory test activation Environment

CD test
source./bin/activate

At this point, you are entering an isolated environment where the installation, uninstallation, and use of modules will be in the test environment without affecting the system and other environments. Exit Environment

Deactive

the use of Virtualenvwrapper

We can see that the created environment is fragmented, and that the CD is executed and the source is executed to activate the environment.
VW can manage the environment, record the created environment and manage it. Initialization of

After the first installation is complete, you need to set a variable workon_home, which will be used as a prefix for all environments and source/usr/local/bin/virtualenvwrapper.sh

$ mkdir-p $WORKON _home
$ export Workon_home=~/envs
$ source/usr/local/bin/virtualenvwrapper.sh

By adding the Export command and Source command to ~/.bash_profile, you do not have to repeat the initialization of the create environment

Mkvirtualenv env1

mkvirtualenv env2

After the environment is created, it automatically enters the directory and activates the environment. Switching Environments

Workon env1

Workon env2

List Existing Environment

Workon

Exit Environment

Deactivate

Delete Environment

Rmvirtualenv

Create Project

The project will be created into the Project_home directory, which is actually equivalent to building an environment under a directory.

 Mkproject  

Reference

http://liuzhijun.iteye.com/blog/1872241
http://virtualenvwrapper.readthedocs.org/en/latest/
http://www.virtualenv.org/en/latest/