* recommended to use "python3 setup.py develop", it makes life a lot easier.
* epydoc (old but still relevant) to be used to extract docstrings. again
goes in Makefile
+* some people may use pypy3, others python3.6, others python3.7. do NOT
+ hard-code the python executable name into Makefiles / scripts, use
+ $(PYTHON3) as an optional env-var (PYTHON3 ?= "python3")
* unit tests (python setup.py test) always to be developed extensively
(synergistically) at time of code writing, NOT as an afterthought.
* do not use import * !