Introduction to Data Structures and Algorithms With Python

my_list=["melon","apple","mango"]

#access a list itemprint(my_list[2])#append()  Adds an element at the end of the listmy_list.append("orange")#clear()  Removes all the elements from the listmy_list.clear()#copy()  Returns a copy of the listmy_list.copy()#extend()Adds list items to the end of the current list my_list.extend(another_list)#insert()  Adds an element at the specified position\indexmy_list.insert(3,"guava")#pop()  Removes the element at the specified position\indexmy_list.pop(1)#remove()  Removes the item with the specified valuemy_list.remove("apple")#reverse()  Reverses the order of the listmy_list.reverse()#sort()  Sorts the list alphanumerically, ascending, by default:my_list.sort()

#create a tuplenumber=(45,34,678)#access a tuple itemnumber[0]#delete a tupledel number

y=list(number)#add the list method you want performed e.g sort()y.sort()number=tuple(y)

dog = {'name':'Cara','color':'Brown','gender':'Female'}

#keys()  prints out all the keysfor i in dog.keys():   print(i)#values()  prints out all the valuesfor i in dog.values():   print(i)#items() prints out the key:value pairfor i in dog.items():   print(i)

namecolorgenderCaraBrownFemale('name', 'Cara')('color', 'Brown')('gender', 'Female')

print(dog.get('sound',0))

0

myset = {"apple", "banana", "cherry"}

# Creating a stackdef create_stack():    stack = []    return stack# Creating an empty stackdef check_empty(stack):    return len(stack) == 0# Adding items into the stackdef push(stack, item):    stack.append(item)    print("pushed item: " + item)# Removing an element from the stackdef pop(stack):    if (check_empty(stack)):        return "stack is empty"    return stack.pop()stack = create_stack()push(stack, str(1))push(stack, str(2))push(stack, str(3))push(stack, str(4))print("popped item: " + pop(stack))print("stack after popping an element: " + str(stack))

pushed item: 1pushed item: 2pushed item: 3pushed item: 4popped item: 4stack after popping an element: ['1', '2', '3']

# Queue implementation in Pythonclass Queue:    def __init__(self):        self.queue = []    # Add an element    def enqueue(self, item):        self.queue.append(item)    # Remove an element    def dequeue(self):        if len(self.queue) < 1:            return None        return self.queue.pop(0)    # Display  the queue    def display(self):        print(self.queue)    def size(self):        return len(self.queue)q = Queue()q.enqueue(1)q.enqueue(2)q.enqueue(3)q.enqueue(4)q.enqueue(5)q.display()q.dequeue()print("After removing an element")q.display()

[1, 2, 3, 4, 5]After removing an element[2, 3, 4, 5]

# Linked list implementation in Pythonclass Node:    # Creating a node    def __init__(self, item):        self.item = item        self.next = Noneclass LinkedList:    def __init__(self):        self.head = Noneif __name__ == '__main__':    linked_list = LinkedList()    # Assign item values    linked_list.head = Node(1)    second = Node(2)    third = Node(3)    # Connect nodes    linked_list.head.next = second    second.next = third    # Print the linked list item    while linked_list.head != None:        print(linked_list.head.item, end=" ")        linked_list.head = linked_list.head.next

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