Translations:Manual:Creating parametric objects/7/en

All Python classes usually have an __init__ method. What is inside that method is executed when that class is instantiated (which means, in programming slang, that a Python Object is created from that class. Think of a class as a "template" to create live copies of it). In our __init__ function here, we do two important things: 1- store our class itself into the "Proxy" attribute of our FreeCAD document object, that is, the FreeCAD document object will carry this code, inside itself, and 2- create all the properties our object needs. There are many types of properties available, you can get the full list by typing this code: