Tasks

class Task:
    def __init__(self, title):
        self.title = title
        self.completed = False
    
    def complete(self):
        self.completed = True
    
    def __str__(self):
        status = "Done" if self.completed else "Pending"
        return f"{self.title} - {status}"

def main():
    tasks = []
    
    while True:
        print("\n1. Add Task")
        print("2. List Tasks")
        print("3. Mark Task as Completed")
        print("4. Delete Task")
        print("5. Exit")
        
        choice = input("Enter your choice (1-5): ")
        
        if choice == '1':
            title = input("Enter task title: ")
            tasks.append(Task(title))
            print("Task added!")
        
        elif choice == '2':
            if tasks:
                print("\nTasks:")
                for idx, task in enumerate(tasks, 1):
                    print(f"{idx}. {task}")
            else:
                print("No tasks.")
        
        elif choice == '3':
            if tasks:
                idx = int(input("Enter task number to mark as completed: ")) - 1
                if 0 <= idx < len(tasks):
                    tasks[idx].complete()
                    print("Task marked as completed.")
                else:
                    print("Invalid task number.")
            else:
                print("No tasks.")
        
        elif choice == '4':
            if tasks:
                idx = int(input("Enter task number to delete: ")) - 1
                if 0 <= idx < len(tasks):
                    del tasks[idx]
                    print("Task deleted.")
                else:
                    print("Invalid task number.")
            else:
                print("No tasks.")
        
        elif choice == '5':
            print("Exiting...")
            break
        
        else:
            print("Invalid choice. Please enter a number from 1 to 5.")

if __name__ == "__main__":
    print("Welcome to the To-Do List Application!")
    main()