Features from other languages I wish were Python builtins:
- Haskell algebraic data types + syntactic sugar
- C/Lisp macros
- Haskell algebraic data types + syntactic sugar
- C/Lisp macros
For sum types we have enums, and for product types we have tuples (or namedtuples or dataclasses). Sugar could be done with decorators or metaclasses.
For Lisp macros, there's macropy and Hissp.
https://www.gnu.org/software/m4/
https://threeofwands.com/algebraic-data-types-in-python/
There are issues with using stand-alone implementations of C preprocessing like GNU cpp with languages that deviate from C in their token syntax.