Python is an interpreted language; When a program is run, the python interpreter is first parsing your code and checking for any syntax errors, then it is translating the source code into a series of bytecode instructions; these bytecode instructions are then run by the python interpreter. This text is explaining some of the features of the python bytecode.

The byte code deals with two entities, a memory store that keeps functions and data items, and a stack used for evaluating expression (the stack is maintained separately per each function object) The python interpreter works as a stack machine when it evaluates the bytecode instructions. This means that values are moved from a main memory store to the stack, where the expression is evaluated, then the result is moved back to the main memory store.

You can examine the Python bytecode of a function by means of a dissassembler, as part of the python standard library you have the dis package, that can show you the bytecode of a python function.

I have written a disassembler that is producing a combined listing for a given python function, this means that you have a line of the python source code, followed by the python bytecode instructions that this source line translates into; I hope that this combined listing will make it much easier to comprehend the meaning of each lineof code and how it translates into the byte code instructions.

Read more on GitHub.