Totally agree with this person's assessment on types.
I took over a smallish half-completed web application written in python a couple of years ago. Nothing major - simple business-y analytics/data viewing app with some fancy charts and tables etc - perhaps a couple of thousand lines of code interfacing to backend database unique to our business. It had some tests, but nowhere near 100% coverage. I needed to finish it off and then get it into production.
Long-story short, trying to understand someone's half-completed python and make changes to this was a HUGE nightmare for precisely the reason the article outlines: python expects you to remember all the minutiae of all the code you are calling. If you cant remember, then you need to suck it up and pick your way through the code and mentally keep track of what is going on at every stack frame.
So instead of thinking about the actual problem you're trying to solve, python forces you keep track of all the little bullshit that you shouldn't need to care about. And even then, you cant be 100% sure you got it right until you exercise that code (either through 100% test coverage, or - shudder - at run-time at 3am on a Sunday when a user in Japan logs on).
So far from being productive and "easy to use", python for us was a nightmare of low-productivity and frustration in only a very small application being worked on by just 2 or 3 remote developers. I cant imagine the levels of pain and suffering for larger projects & teams!
The "solution" is apparently extensive & specially crafted comments that specifically explain the types used (that of course needs to be kept up to date) - I find this fairly odious (why not just use a typed language if you need to put the types in the comments?!)
I know now that Python is looking at type hints as part of the language (PEP 484 - https://www.python.org/dev/peps/pep-0484/) that should help a lot.
Still, its not all bad. As a result of the pain of this application (which incidentally was damn slow in production due to the processing we had to do on the data in the python backend before we sent it to the browser), we decided to learn golang and use that for future work instead and have not looked back.
Golang has the same feeling of fast-paced "throw things at the screen" productivity, but is obviously typed (so you know about errors before your users do) and orders of magnitude faster.