<s>[INST] Is there a python equivalent of Ruby's 'rvm'? Q: Do we have anything functionally equivalent in Python to the Ruby version manager 'rvm'? 

(RVM lets you easily switch completely between different versions of the ruby interpreter and different sets of gems (modules). Everything concerning download-build-install-switch  of interpreter(-s) and gems gets taken care of by invoking rvm. It is all run under your regular user account.)
 [/INST] Pythonbrew is no longer under development. The former maintainer suggests to use "PyEnv" instead (see below)".
pythonbrew has come!
http://github.com/utahta/pythonbrew
pyenv: https://github.com/yyuu/pyenv
 </s>