This library provides two fundamental near-trivial data structures for Python:
Eitheralso known as "coproduct", "sum type", "variant", "tagged union", "disjoint union", etc: A value that comes from one of two sets
Maybealso known as "option" or "Either Nothing": A value that may be missing. (Python has "None" but it does not compose)
Each is ~10 lines, mostly boilerplate, but now they are in one place in a library.
If you are unfamiliar with these concepts, here is some reading from around the web:
Copyright 2012- Kenneth Knowles
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