Bootstrapping pip using ensurepip

Slowly, the pip package manager has been replacing easy_install since its introduction in 2008. Since Python 3.4, it has even become the default and is bundled with Python. Since Python 3.4 onward, it is installed by default within both the regular Python environment and that of pyvenv; before that, a manual install is required. To automatically install pip in Python 3.4 and above, the ensurepip library is used. This is a library that handles automatic installation and/or upgrades of pip, so it is at least as recent as the one bundled with ensurepip.