object-oriented programming upon reading the titleone could wonder why object-oriented programming (oopis introduced only now we have used objects since and we started making our own classes and object types in so what is new in the answer is that the term oop can have two different meanings the first simply involves programming with objects and classeswhich we introduced in and is more commonly referred to as object-based programming the second meaning of oop is programming with class hierarchieswhich are families of classes that inherit their methods and attributes from each other this is the topic of the present we will learn how to collect classes in families (hierarchiesand let child classes inherit attributes and methods from parent classes class hierarchies and inheritance class hierarchy is family of closely related classes organized in hierarchical manner key concept is inheritancewhich means that child classes can inherit attributes and methods from parent classes typical strategy is to write general class as base class (or parent classand then let special cases be represented as subclasses (child classesthis approach can often save much typing and code duplication as usualwe introduce the topic by looking at some examples classes for lines and parabolas as first examplelet us create class for representing and evaluating straight linesy following the concepts and ideas introduced in the implementation of the class can look like import numpy as np class line(cthe author( sundnesintroduction to scientific programming with pythonsimula springerbriefs on computing