A rootkit is the thing you install once you have root - not a way to get root initially. It usually gives the attacker a means to access the machine in the future, even if the vulnerability she used is fixed in the future.
Rootkits are designed to hide themselves. They are essentially attacker installed backdooors.
A backdoor is basically a rootkit that is part of the original software as written by the original developer. The words have different connotations (rootkit is extremely negative, backdoors slightly less).
The point the article makes on comparing floating point values and the floating point type is true, but it's not because of any rounding error.
It's because the comparison operators are defined for every value. That is, "True < []" is valid in Python 2.7, along with any other 2 values, regardless of type. This is a surprising instance of weak typing in Python, which is otherwise strongly typed, which is why this was fixed in Python 3 (https://docs.python.org/3.0/whatsnew/3.0.html#ordering-compa...).
This is also not a case of Python doing something useful, like with '"foo"*2'. The result of the comparison is defined, but it's not useful. I suppose it was useful for making sure that you can always sort a list, but there are better ways to do that.
The real story here is that a 10th grader, after using a Theorem that wasn't taught in class, was encouraged to prove it - which she did, successfully.
The teacher then sent it to a few academics who were thought that was a rather impressive accomplishment for a 10th grader, so they wrote her some encouraging words. That's it.
A rootkit is the thing you install once you have root - not a way to get root initially. It usually gives the attacker a means to access the machine in the future, even if the vulnerability she used is fixed in the future.
Rootkits are designed to hide themselves. They are essentially attacker installed backdooors.
A backdoor is basically a rootkit that is part of the original software as written by the original developer. The words have different connotations (rootkit is extremely negative, backdoors slightly less).