pre-defined and programmer-supplied methods for class to define it formallya method is function that can be invoked on an object using the object-oriented call syntax that for python is of the form obj method()where obj may either be an instance of class or the class itself thereforethe pre-defined functions that can be invoked on either the class itself or on class instance using the object-oriented syntax are also methods the pre-defined attributesboth variables and methodsemploy special naming conventionthe names begin and end with two underscores python makes distinction between function objects and callables while all function objects are callablesnot all callables are function objects purdue university