go: /usr/local/cpython-3.7/bin/mypy --disallow-untyped-calls bst.py test-bst.py /usr/local/cpython-3.5/bin/python3 ./test-bst.py /usr/local/cpython-3.7/bin/python3 ./test-bst.py /usr/local/pypy3-6.0.0/bin/pypy3 ./test-bst.py # AttributeError: 'module' object has no attribute 'Optional' # This version of Micropython is closest to CPython 3.4, which is missing some functionality from the typing module. # /usr/local/micropython-git-2018-06-06/bin/micropython ./test-bst.py go2: ./big clean: rm -rf __pycache__ .mypy_cache