Python virtualenv primer
Posted on April 09, 2014
- and tagged as
- python
virtualenv is a Python package which enables the creation of isolated environments for projects. This allows different version of packages (Djano, for example) to co-exist on the same system and be used for different projects. This means cleaner systems (the only Python package which needs to be installed globally is virtualenv), easier application packaging and testing through simply copying a virtualenv environment.
Install or upgrade virtualenv
pip istall virtualenv
pip install virtualenv --upgrade
Creating a virtualenv
To create a new environment, run the following command
# virtualenv --no-site-packages cdb
New python executable in cdb/bin/python Installing setuptools, pip…done.
The --no-site-packages
option instructs virtualenv to not symlink packages
installed the global site-packages to the virtualenv if that same package is
installed globally.
Using a virtualenv
Once the virtualenv has been created, we need to activate it in order to use it. Activation updates the $PATH environment variable to the virtualenv.
[root@srv-testlab1 virtualenvs]# cd cdb/
[root@srv-testlab1 cdb]# source bin/activate
(cdb)[root@srv-testlab1 cdb]#
Once activated, the virtualenv name will be prepended to the prompt. To
deactivate, or ‘log out’ of an environment, run deactivate
From here we can install required packages using pip and begin working on our project.