Import self-made Sage modules and functions into Sage script?

Update Jan 2020: E.M. Bray suggests a more elegant solution in the comments, see: https://ask.sagemath.org/question/7867/importing-sage-files/?answer=48947#post-id-48947. — Let’s say that I have created a bunch of Sage code — Sage functions etc. — that I wish to reuse by importing into various Sage scripts. In straight Python, one would put these functions into their own separate file and import them using the usual from foo import … Continue reading Import self-made Sage modules and functions into Sage script?