Linear Data Structures

Linear Data Structures

1. Lists

   • Ordered: elements of a list can be accessed using their indexes
   • Changeable: elements can be added to or deleted from the list
   • Allow duplicates: multiple elements can be the same
   • Elements in the list can be of different data types
   • petExample = [ "dog", "golden retriever", 3, True]
     • To add an element: petExample.append("Penny")
       • petExample = ["dog", "golden retriever", 3, True, "Penny"]
         • To delete an element: petExample.remove(3)
           • petExample = ["dog", "golden retriever", True, "Penny"]
             • To access an element: petType = petExample[0]
               • petType = "dog"

2. Tuples

   • Ordered: elements of a tuple can be accessed using their indexes
   • Unchangeable: elements cannot be added to or deleted from the tuple
   • Allow duplicates: multiple elements can be the same
   • Elements in the tuple can be of different data types
   • petExample = ("dog", "golden retriever", 3, True)
     • petName = ("Penny",)
       • To access an element: petType = petExample[0]
         • petType = "dog"
           • To access multiple elements: print(petExample[1:3])
             • ('golden retriever', 3)

3. Sets

   • Unordered: elements of a set cannot be accessed using their indexes
   • Unchangeable: elements cannot be changed, but elements can be added
   • Reject duplicates: multiple elements cannot be the same
   • Elements in the set can be of different data types
   • petExample = {"dog", "golden retriever", 3, True}
     • To add an element: petExample.add("Penny")
       • Two sets can be merged: petStats = {"Medium", 25}
         • petExample.update(petStats)
           • petExample = {"dog", "golden retriever", 3, True, "Penny", "Medium", 25}

4. Dictionaries

   • Unordered: elements of a dictionary cannot be accessed using their indexes
   • Changeable: elements can be added to and changed in the dictionary
   • Reject duplicates: multiple keys cannot be the same
   • Elements in the dictionary can be of different data types
   • Stores data in the dictionary in key : value format
     • key : value "age" : 19
       • petExample = { "pet type" : "dog", "breed" : "golden retriever", "age" : 3, "fixed" : True}
         • To add a key : value: petExample["name"] = "Penny"
           • To change a value in one of the keys: petExample["age"] = 4
             • petExample = { "pet type" : "dog", "breed" : "golden retriever", "age" : 4, "fixed" : True, "name" : "Penny"}
               • To access a value in a key: theBreed = petExample["breed"]
                 • theBreed = "golden retriever"