I went through this article some time ago and, while it's certainly neat implementation and worth understanding (that was the first recursive generator that made sense to me - thanks to this I had much easier time understanding Scheme's call/cc and it's uses), it needs to be noted that it is not a generic monad implementation. You can not, for example, implement list monad (I tried very hard and couldn't, I saw the same said in comments below the article, but if it's possible please let me know!) using this implementation and syntax, because you can not "rewind" Python's generators.

So, while it's nice implementation for some kinds of monads it's not nearly general enough to be (IMHO) called "monads in Python" - it is possible to implement fully general monads in Python, but you need nested lambdas and there is no getting away from it.

Still, very nice hack and worth spending an evening (or two) to understand how it works.