attributespre-defined vs programmer-supplied class in python comes with certain pre-defined attributes the pre-defined attributes of class are not to be confused with the programmer-supplied attributes such as the class and instance variables and the programmer-supplied methods by the same tokenan instance constructed from class is an object with certain pre-defined attributes that again are not be confused with the programmer-supplied instance and class variables associated with the instance and the programmer-supplied methods that can be invoked on the instance purdue university