I think it is best to have some understanding of how an OS works, and how Python works, before asking whether you can write an OS in Python.
Python is basically a scripting wrapper around a bunch of C functions ("builtins") and there are means of installing additional C functions if you need them. Without any of the builtins, you really can't do much of anything. For example, "print(2+2)" computes the string "4" (by adding 2+2 and converting the result to decimal), then calls a builtin to actually print the string on the console.
For an OS, you will need quite a few more C functions, mostly to control timers and task switching, the main functions of an OS. Given enough C functions though, in principle you can write an OS.
I want to know how they got the nuke stuff in the first place. That's potentially much more disruptive than any number of drug deals.