What is pyenv?

Want to have multiple python version ( 2.2.x, 2.3.x, 3.5.x, 3.5.x, etc) without messing with your laptop? Manage virtual env easily? Pyenv is your tool.

Installing and configuring pyenv

pyenv install 3.6.0 - installs python 3.6.0 in pyenv
pyenv install --list or pyenv install --list | grep 3.6 view all python version 3.6.x that you can install
pyenv global 3.6.0 - activates/enables 3.6.0 version of python
python -V or pyenv version -V to view enabled python
pyenv versions - list all the python available in pyenv
pyenv global system - will undo the activated python and switch to the python install in your machine/system
pyenv local 2.7.18 - will create a .python-version file. We use this command to define folder/project specific python. Basically if you are in this folder, python command will be resolved to python 2.7.18. You can also verify it by pyenv versions
We can set python version by 3 ways pyenv shell 3.8, pyenv local 2.7.18 and pyenv global 3.5.9

pyenv virtualenv <python_version> <env_name> - eg pyenv virtualenv 3.5.9 my_env - will creates a python env with my_env name
activate this newly created env - pyenv activate my_env
if you want to automatically activate this env after navigating to a project folder if do pyenv virtualenv 3.5.9 my_env > navigate to project > pyenv local my_env > will create .python-version file with content my_env so that pyenv-virtualenv plugin will know that you have already an env for this folder and activates this. Navigating out of this folder will deactivate the env
It also supports multiple env at once. pyenv local env1 env2 - command will try to be resolved in env2 if failed then it will use env2