Why MIT switched from Scheme to Python (2009)

Python offers quite good multi-paradigm support and could absolutely be used to explore many key concepts from SICP (granted, nothing is as meta-programmable as the Lisp family, since AST manipulation in other languages requires additional steps to actually obtain an AST). In particular, since Python's object model includes functions, higher-order functions are possible (and indeed, `map` is a builtin, and `reduce` is in the standard library after previous demotion from builtin status). Nowadays of course it's fashionable to litter the code with manifest type hints, which are a distraction to that sort of pedagogy. However, they are still entirely optional, have zero-to-generally-irrelevant effect at runtime, and can simply be disregarded.