PyMonad implements data structures typically available in pure functional or functional first programming languages like Haskell and F#. Included are Monad and Monoid data types with several common monads included - such as Maybe and State - as well as some useful tools such as the @curry decorator for defining curried functions. PyMonad 2.x.x represents an almost complete re-write of the library with a simpler, more consistent interface as well as type annotations to help ensure correct usage.
Can't believe I missed that for so long. Thanks!