| class Empty(Exception): | |
| pass | |
| class ArrayStack: | |
| def __init__(self): | |
| self._data = [] | |
| def __len__(self): | |
| return len(self._data) | |
| def is_empty(self): | |
| return len(self._data) == 0 | |
| def push(self, e): | |
| self._data.append(e) | |
| print("The element", e, "is pushed successfully") | |
| def top(self): | |
| if self.is_empty(): | |
| raise Empty("Stack is Empty!") | |
| return self._data[-1] | |
| def pop(self): | |
| if self.is_empty(): | |
| raise Empty("Stack is Empty!") | |
| return self._data.pop() | |
| print("\t Stack ADT Implementation") | |
| print("\t---------------------------------") | |
| stack = ArrayStack() | |
| while True: | |
| print("\n\t Stack Operations:") | |
| print("1 - Push") | |
| print("2 - Pop") | |
| print("3 - Top element") | |
| print("4 - Length of stack") | |
| print("5 - Is empty") | |
| print("6 - Display stack elements") | |
| print("7 - Exit") | |
| ch = int(input("Enter your choice: ")) | |
| try: | |
| if ch == 1: | |
| e = int(input("Enter the element: ")) | |
| stack.push(e) | |
| elif ch == 2: | |
| t = stack.pop() | |
| print("The element", t, "is popped successfully") | |
| elif ch == 3: | |
| t = stack.top() | |
| print("The top element in the stack is", t) | |
| elif ch == 4: | |
| print("Number of elements in stack is", len(stack)) | |
| elif ch == 5: | |
| if stack.is_empty(): | |
| print("Stack is Empty") | |
| else: | |
| print("Stack is not empty") | |
| elif ch == 6: | |
| if stack.is_empty(): | |
| print("Stack is empty") | |
| else: | |
| print("Elements in stack (Top to Bottom):") | |
| for i in range(len(stack) - 1, -1, -1): | |
| print("|", stack._data[i], "|") | |
| print("-------------") | |
| elif ch == 7: | |
| print("Program exited") | |
| break | |
| else: | |
| print("Invalid choice") | |
| except Empty as e: | |
| print(e) | |
| except ValueError: | |
| print("Please enter a valid number") | |