three basic data structures objectives to understand the abstract data types stackqueuedequeand list to be able to implement the adts stackqueueand deque using python lists to understand the performance of the implementations of basic linear data structures to understand prefixinfixand postfix expression formats to use stacks to evaluate postfix expressions to use stacks to convert expressions from infix to postfix to use queues for basic timing simulations to be able to recognize problem properties where stacksqueuesand deques are appropriate data structures to be able to implement the abstract data type list as linked list using the node and reference pattern to be able to compare the performance of our linked list implementation with python' list implementation what are linear structureswe will begin our study of data structures by considering four simple but very powerful concepts stacksqueuesdequesand lists are examples of data collections whose items are ordered depending on how they are added or removed once an item is addedit stays in that position relative to the other elements that came before and came after it collections such as these are often referred to as linear data structures linear structures can be thought of as having two ends sometimes these ends are referred to as the "leftand the "rightor in some cases the "frontand the "rear you could also call them the "topand the "bottom the names given to the ends are not significant what distinguishes one linear structure from another is the way in which items are added and removedin particular the location where these additions and removals occur for examplea structure might allow