This does not seems to answer the question: What is the recommended way to install pip on Snappy Ubuntu Core?
It appears that Ubuntu Core 16.04 only has Python 3.
How do I get Python 2 if there is no such a snap?
This system's rootfs is completely read-only and does not even have
chroot based "classic mode" does not work (or at least, not straightforward), because I am considering to use it in a system service style program that starts with the system.
Maybe you think I am using snappy Ubuntu Core in the wrong way, but that is what I have now and cannot switch to a different distro.