the python list pythonas indicated earlieris built using the language with many of the data types and classes available in python actually implemented using appropriate types available in python' list structure is mutable sequence container that can change size as items are added or removed it is an abstract data type that is implemented using an array structure to store the items contained in the list in this sectionwe examine the implementation of python' listwhich can be very beneficial not only for learning more about abstract data types and their implementations but also to illustrate the major differences between an array and python' list structure we explore some of the more common list operations and describe how they are implemented using an array structure creating python list suppose we create list containing several valuespylist which results in the list(constructor being called to create list object and fill it with the given values when the list(constructor is calledan array structure is created to store the items contained in the list the array is initially created bigger than neededleaving capacity for future expansion the values stored in the list comprise subarray in which only contiguous subset of the array elements are actually used figure illustrates the abstract and physical views of our sample list in the physical viewthe elements of the array structure used to store the actual contents of the list are enclosed inside the dashed gray box the elements with null references shown outside the dashed gray box are the remaining elements of the underlying array structure that are still available for use this notation will be used throughout the section to illustrate the contents of the list and the underlying array used to implement it abstract view length physical view capacity array figure the abstract and physical views of list implemented using an array