to be considered "new styleand enable and obtain all new-style behavior classes without this are "classic because all classes are automatically new-style in xthe features of new-style classes are simply normal class features in that line 've opted to keep their descriptions in this section separatehoweverin deference to users of python code--classes in such code acquire new-style features and behavior only when they are derived from object in other wordswhen python users see descriptions of "new styletopics in this bookthey should take them to be descriptions of existing properties of their classes for readersthese are set of optional changes and extensions that you may choose to enable or notunless the code you must use already employs them in python xthe identifying syntactic difference for new-style classes is that they are derived from either built-in typesuch as listor special built-in class known as object the built-in name object is provided to serve as superclass for new-style classes if no other built-in type is appropriate to useclass newstyle(object)normal class code explicit new-style derivation not required in xautomatic any class derived from objector any other built-in typeis automatically treated as new-style class that isas long as built-in type is somewhere in its superclass treea class acquires new-style class behavior and extensions classes not derived from built-ins such as object are considered classic just how new is new-styleas we'll seenew-style classes come with profound differences that impact programs broadlyespecially when code leverages their added advanced features in factat least in terms of its oop supportthese changes on some levels transform python into different language altogether--one that' mandated in the lineone that' optional in only if ignored by every programmerand one that borrows much more from (and is often as complex asother languages in this domain new-style classes stem in part from an attempt to merge the notion of class with that of type around the time of python though they went unnoticed by many until they were escalated to required knowledge in you'll need to judge the success of that merging for yourselfbut as we'll seethere are still distinctions in the model--now between class and metaclass--and one of its side effects is to make normal classes more powerful but also substantially more complex the new-style inheritance algorithm formalized in for examplegrows in complexity by at least factor of stillsome programmers using straightforward application code may notice only slight divergence from traditional "classicclasses after allwe've managed to get to this point in this book writing substantial class exampleswith mostly just passing mentions advanced class topics