Hiding implementation details

Let's stay with the preceding example to talk about this point as well. You can see that, by going through the code of the do_report function, you can get a pretty good understanding without reading one single line of implementation. This is because functions hide the implementation details. This feature means that, if you don't need to delve into the details, you are not forced to, in the way you would if do_report was just one big, fat function. In order to understand what was going on, you would have to read every single line of code. With functions, you don't need to. This reduces the time you spend reading the code and since, in a professional environment, reading code takes much more time than actually writing it, it's very important to reduce it by as much as we can.