[Peristarkawan]

The reason for using keywords is that there is no guarantee that the next class in the MRO after ColoredShape will be Shape. When the instance is a ColoredShape, it will be, but if ColoredShape is subclassed with a more complex inheritance structure, then something else could end up in between them in the MRO.

Thus, ColoredShape.__init__ can't simply pass on shapename to the super method, because that might not be the argument expected by the next __init__ method in the MRO. Instead, each method needs to gracefully accept arbitrary arguments and then pass on whatever it received (minus what it consumed).