Using properties to add behavior to class data

Throughout this book, we've been focusing on the separation of behavior and data. This is very important in object-oriented programming, but we're about to see that, in Python, the distinction can be eerily blurry. Python is very good at blurring distinctions; it doesn't exactly help us to "think outside the box". Rather, it teaches us that the box is in our own head; "there is no box".

Before we get into the details, let's discuss some bad object-oriented theory. Many object-oriented languages (Java is the most guilty) teach us to never access attributes directly. They teach us to write attribute access like this:

class Color:
    def __init__(self, rgb_value, name):
        self._rgb_value = rgb_value
        self._name = name

    def set_name(self, name):
        self._name = name
    
    def get_name(self):
        return self._name

The variables are prefixed with an underscore to suggest that they are private (in other languages it would...