Another useful Python version manager is asdf with python plugin. The most helpful feature of asdf is ability to specify what Python version to use in certain directory by simply placing a .tool-versions file (contains the version number to use) in that directory. This makes working with multiple projects that requires different version of Python very seamless.
pyenv also has this with the .python-version file which will switch versions. And with the plugin, you can use virtualenvs in pyenv so that a .python-version can be simply: my-cool-project-virtualenv and switching to that directory automatically switches to it.