Python-Data-Structures/Stack implementation using List at master · ayushi1376/Python-Data-Structures · GitHub

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# A.STACKS:
# A-1:STACK IMPLEMENTATION USING ARRAYS(PTYHON'S LIST):
# #A-1-a:Dynamic implementation(stack can grow to any length)

class EmptyClassException(Exception):
    pass
class Stack:
    def __init__(self):
        self.item=[]
    def is_empty(self):
        return self.item==[]
    def stack_len(self):
        return len(self.item)
    def pop(self):
        if self.is_empty():
            raise EmptyClassException("Stack is Empty!!")
        return self.item.pop()
    def push(self,ele):
        self.item.append(ele)
    def peek(self):
        if self.is_empty():
            raise EmptyClassException("List is Empty!!")
        return self.item[-1]
    def display(self):
        print(self.item)

if __name__=="__main__":
    stack=Stack()

    while True:
        print("1.Push.")
        print("2.Pop.")
        print("3.Peek.")
        print("4.Size.")
        print("5.Display.")
        print("6.Quit")

        choice=int(input("Enter a choice: "))
        if(choice==1):
            ele=int(input("Enter the elements: "))
            stack.push(ele)
        elif(choice==2):
            popped=stack.pop()
            print("Popped element is : ",popped)
        elif(choice==3):
            print("Element at the top is : ",stack.peek())
        elif(choice==4):
            print("Size of the stack is: ",stack.stack_len())
        elif(choice==5):
            stack.display()
        elif(choice==6):
            break
        else:
            print("Invalid choice!!")
        print()


# A-1-b:Static implementation(stack is fixed lengthed)

class StackEmptyError(Exception):
    pass
class StackFullError(Exception):
    pass

class Stack:
    def __init__(self,max_len=10):
        self.item=[None]*max_len
        self.count=0

    def size(self):
        return self.count
    def is_empty(self):
        return self.item==0
    def is_full(self):
        return self.item==len(self.item)
    def push(self,ele):
        if self.is_full():
            raise StackFullError("List is Full!!")
        self.item[self.count]=ele
        self.count+=1
    def pop(self):
        if self.is_empty():
            raise StackEmptyError("List is Empty!!")
        ele=self.item[self.count-1]
        self.item[self.count-1]=None
        self.count-=1
        return ele
    def peek(self):
        if self.is_empty():
            raise StackEmptyError("List is Empty!!")
        return self.item[self.count-1]
    def display(self):
        print(self.item)

if __name__=="__main__":
    stack=Stack()

    while True:
        print("1.Push.")
        print("2.Pop.")
        print("3.Peek.")
        print("4.Size.")
        print("5.Display.")
        print("6.Quit")

        choice=int(input("Enter a choice: "))
        if(choice==1):
            ele=int(input("Enter the elements: "))
            stack.push(ele)
        elif(choice==2):
            popped=stack.pop()
            print("Popped element is : ",popped)
        elif(choice==3):
            print("Element at the top is : ",stack.peek())
        elif(choice==4):
            print("Size of the stack is: ",stack.size())
        elif(choice==5):
            stack.display()
        elif(choice==6):
            break
        else:
            print("Invalid choice!!")
        print()