arrays the length of the listobtained using len()is the number of items currently in the subarray and not the size of the underlying array the size or capacity of the array used to implement the list must be maintained in order to know when the array is full python does not provide method to access the capacity value since that information is not part of the list definition appending items what happens when new item is appended to the end of list as in the following statementpylist append if there is room in the arraythe item is stored in the next available slot of the array and the length field is incremented by one the result of appending to pylist is illustrated in figure pylist figure result of appending value to the list what happens when the array becomes full and there are no free elements in which to add new list itemfor exampleconsider the following list operationspylist append pylist append pylist append after the second statement is executedthe array becomes full and there is no available space to add more values as illustrated in figure by definitiona list can contain any number of items and never becomes full thuswhen the third statement is executedthe array will have to be expanded to make room for value from the discussion in the previous sectionwe know an array cannot change size once it has been created to allow for the expansion of pylist figure full array resulting after appending three values