class attribute class attribute defined at top of class persondefined at top of class personclass company "ucdcompany "ucdclass person( person( person( person( age age print age print age person(person( person( company person()"ibmprint company company "ibm'ibmprint company 'ibmdef def __init__(self)__init__(self)self age self age = instance attribute instance attribute defined inside class defined inside class function function the self prefix the self prefix is is always required always required change attribute ageage changetotoinstance instance attribute affects only the associated affects only the associated instance ( instance ( change to class attribute company affects ( and company changealltoinstances class attribute affects all instances ( and