Cython also has had a mechanism for this for a long time. In fact if you wanted multiple dispatch in a new pure C program in 2020, just write it in Cython with no use of the CPython API and have Cython generate the pure C library for you.

https://cython.readthedocs.io/en/latest/src/userguide/fusedt...

Also there's this: https://pypi.org/project/multipledispatch/

Ditto for this; it works very well with type hints. I used it in func-analysis [0], a tool I put together to learn about duck typing.

[0]: https://gitlab.com/Seirdy/func-analysis

SQLAlchemy has too this for hybrid attributes/expressions.

https://docs.sqlalchemy.org/en/13/orm/mapped_sql_expr.html