Here is the obligatory Car Analogy
High Level == Turn By Turn Directions
Imagine Python ( or any other high level language ) is like giving directions to someone on how to drive from Point A to Point B based at the same high level, turn by turn.
Turn by turn directions don't bother with details about what car you are driving, or any of the minutia involved with starting the car or using the brakes or anything like that. They just tell you what to do ( Python ) and assume you ( Python Runtime ) can make the machine ( computer ) do what it needs to do to accomplish the goal ( getting to Point B ).
Assembly == Microscopic Burdensome Context Dependent Details
Imagine having to tell someone every minute detail about how to build a car before they can even start the engine.
Then based on which car how to start the car ( keys vs buttons vs voice activation, etc ), on when and how to put the car in gear ( based on transmission type, manual, auto, cvt, etc ) and then when to select each gear, and how to select them each time. When and how to press the accelerator pedal down to absolute values of how much. When and how to apply the brakes ( manual or power or anti-lock ) in absolute values of how much.
Now you have the most finite detailed control over exactly what happens when but you also have to be exactly correct to a level of detail that is extremely hard to manage. But only if you know the details of all these components ( CPU, FPU, etc. ) because ASM is machine specific.
But it would be extremely burdensome to communicate to another how to get from the same Point A to Point B in this manner.
Do we really need to know every detail of automotive engineering to drive a car?
Windows, Apple, AOL, MSN, Geocities, myspace and Facebook they all show us that no we don't have to know any of this stuff to use a computer.
As a developer that does only General Programming with High Level Languages and doesn't write compilers or anything else that translates directly to machine code ( virtual machines with JIT compilers, bytecode runtimes with JIT compilers, etc ) knowing ASM isn't really going to do you much good.
Knowing how an internal combustion engine that is driven by an ECU you don't control works isn't going to make you a better driver because you can't directly affect the output of the system as a whole.
Learning how Python creates its byte code, or Java creates its byte code might be a better intermediary step because it is basically platform agnostic assembly code. These might be better places to start, you can write the byte code yourself and execute it in both cases.
Obligatory XKCD comic reference!