Creation of virtual environments. The venv module provides support for creating lightweight “virtual environments” with their own site directories, optionally isolated from system site directories.
Each virtual environment has its own Python binary (allowing creation of environments with various Python versions) and can have its own independent set of installed Python packages in its site directories. Creation of virtual environments is done by executing the pyvenv script: Les environnements virtuels Python : virtualenv et virtualenvwrapper. Virtualenv 1.9. Introduction virtualenv is a tool to create isolated Python environments.
The basic problem being addressed is one of dependencies and versions, and indirectly permissions. Imagine you have an application that needs version 1 of LibFoo, but another application requires version 2. How can you use both these applications?