class Rectangle:
    """ The keyword class is used to define a class.
        The name of the class is Rectange.
    """
    def __init__(self, length, width, color='black'):
        """
        Initializes a Rectangle object with a given length, width and color
        """
        self.length = length
        self.width = width
        self.color = color

    """ The special method __init__ is known as the constructor of a
        class. When the statement "rect_1 = Rectange(length=15, width=4, color='red') is called, the __init__ will be invoked.
        
        All methods in a class has one extra parameter. The first paramenter is the object itself, which usually uses the name 'self'.
        
        For example, consider when rect_1.getColor() is called. There is no argument. However, there is one parameter, self, whicch is referencing rect_1.
    """
    def area(self):
        """
        Calculates and returns the area of the rectangle.
        """
        return self.length * self.width

    def perimeter(self):
        """
        Calculates and returns the perimeter of the rectangle.
        """
        return 2 * (self.length + self.width)
        
    def get_color(self):
        return self.color
        
    def __str__(self):
        return f"Rectangle(length: {self.length}, width: {self.width}, color: {self.color})"
        """  __str__ is another standard method, which is invoked when an rectangle object must be converted to a string.
        
        For example, for the statement
            print(f"rect_2: {rect_2}") is executed, __str__ will be invoked in {rect_2}
        """

if __name__ == "__main__":
    # Example usage:
    # Create a Rectangle object
    rect_1 = Rectangle(length=15, width=4, color='red')

    # Access attributes
    print(f"rect_1's length: {rect_1.length}")
    print(f"rect_1's width: {rect_1.width}")
    print(f"rect_1's color: {rect_1.color}")

    # Call methods
    print(f"rect_1's area: {rect_1.area()}")
    print(f"rect_1's perimeter: {rect_1.perimeter()}")
    print(f"rect_1's color: {rect_1.get_color()}")
    
    # When a rectange needs to be converted to a string, __str__ is invoked.
    print(f"rect_1: {rect_1}")
    
    rect_2 = Rectangle(length=8, width=4)
    print(f"rect_2: {rect_2}")
    print(f"rect_2's area: {rect_2.area()}")
    print(f"rect_2's color: {rect_2.get_color()}")