I'm pretty sure that the author of the article didn't mean to imply that you should actually define monads explicitly in Python and start using them in your cod

I'm pretty sure that the author of the article didn't mean to imply that you should actually define monads explicitly in Python and start using them in your code. That would be inelegant, far from idiomatic, and mostly pointless, since Python doesn't type-check your code like Haskell does, and most of the advantages of an explicit Monad class arise from its usage in the presence of a strong type system. The example snippet was likely just an illustrative example, using Python merely because it's a more widely understood language than Haskell. If he wrote it in Haskell, then not only would it be redundant (since monads are already defined in that language), but it would be less comprehensible to the intended audience of new and non-Haskell programmers.