Improving our object-oriented code to provide new features

Now that we have our counter working with the LEDs connected to the board, we want to add new features. We want to be able to easily transform a number between 1 and 9 into its representation in LEDs connected to the board.

The following lines show the code for the new NumberInLeds class. The code file for the sample is iot_python_chapter_03_05.py.

class NumberInLeds:
    def __init__(self):
        self.leds = []
        for i in range(1, 10):
            led = Led(i)
            self.leds.append(led)

    def print_number(self, number):
        print("==== Turning on {0} LEDs ====".format(number))
        for j in range(0, number):
            self.leds[j].turn_on()
        for k in range(number, 9):
            self.leds[k].turn_off()

The constructor, that is, the __init__ method, declares an empty list attribute named leds (self.leds). Then, a for loop creates nine instances of the Led class and each of them represent an LED connected...