That's nowhere near 90% of Python. It's strange because everyone thinks Python is an easy language to learn, but that's not True at all. It's easy to pick up and be productive with it in a very short time, yes, but the interpreter has so much going on you can't learn everything in years. If you happen to learn everything about protocols, the interpreter gotchas, there is the standard library which is also huge, and if you got everything in it, there is the ecosystem, which is so large nobody can know about every package. And I did not talked about the whole new world of Python3, asyncio and the whole old world of Twisted.