Instead of rewriting with static types, they could just gradually add them – Python 3 supports static typing[1] with the actual type-checking done by external[2

Instead of rewriting with static types, they could just gradually add them – Python 3 supports static typing[1] with the actual type-checking done by external[2] tools. [1] https://docs.python.org/3/library/typing.html https://docs.python.org/3/library/typing.html [2] http://www.mypy-lang.org/ http://www.mypy-lang.org/