A powerful alternative to virtualenv is Anaconda - a cross-platform, pip-like package manager bundled with features for quickly making and removing virtual environments. After installing Anaconda, here are some commands to get started:
conda create --name <envname> python=<version>
where <envname> in an arbitrary name for your virtual environment, and <version> is a specific Python version you wish to setup.
# Linux, Mac
source activate <envname>
source deactivate
or
# Windows
activate <envname>
deactivate
conda env list
conda env remove -n <envname>
Find more commands and features in the official conda documentation.