Whether it's easy or not depends on the OS you're working on. On Windows, it's just another executable installer, so it's trivial. On macOS, the official instal

Whether it's easy or not depends on the OS you're working on. On Windows, it's just another executable installer, so it's trivial. On macOS, the official installers are terrible (they have no uninstaller), so you want another way. On Linux etc., some distros have only one Python version in the repos, some have two or three, but the latest versions of all reasonable distros won't let you install Python 3.4.