Python Virtual Environment

1. Install the virtual environment

$ sudo easy_install virtualenv

2. Create a virtual environment

$ virtualenv "env_name】   
For example:
$ virtualenv Virtualtest

Where--no-site-packages can be used to indicates that the virtual environment does not access the global site-packages. So we can isolate a clean test environment even in systems where we have a large number of development packages installed. can be through check Sys.path or "lib/python2.6/no-global-site-packages.txt" file to determine whether to access Global Site-packages .

$ virtualenv--no-site-packages "env_name】
例如：
$ virtualenv --no-site-packages virtualtest

3. Activating the virtual environment

$ source Virtualtest/bin/activate

4. Verifying the libraries used by the virtual environment

(virtualtest) **:~$ which Python (virtualtest)which Easy_install

5. Quit activating the virtual environment

(virtualtest)**:~$ Deactivate

6. Installing a third-party library in a virtual environment

Pip Install *                (here * denotes third-party software library name) *