task_manager.py

class Task:
    def __init__(self, description):
        self.description = description
        self.next = None

class TaskQueue:
    def __init__(self):
        self.front = None
        self.back = None

    def enqueue(self, description):
        new_task = Task(description)

        if self.back is None:
            self.front = new_task
            self.back = new_task
        else:
            self.back.next = new_task
            self.back = new_task

    def dequeue(self):
        if self.front is None:
            return None

        removed = self.front
        self.front = self.front.next

        if self.front is None:
            self.back = None

        return removed

    def display(self):
        current = self.front

        if current is None:
            print("No tasks in queue")
            return

        while current:
            print("-", current.description)
            current = current.next

    def save_to_file(self, filename):
        with open(filename, "w") as f:
            current = self.front
            while current:
                f.write(current.description + "\n")
                current = current.next

    def load_from_file(self, filename):
        try:
            with open(filename, "r") as f:
                for line in f:
                    task = line.strip()
                    if task:
                        self.enqueue(task)
        except FileNotFoundError:
            pass

queue = TaskQueue()
queue.load_from_file("tasks.txt")

while True:
    print("\n" + "=" * 40)
    print("        FIFO TASK MANAGER")
    print("=" * 40)

    print("\n1 - Add single Task")
    print("1.5 - Add multiple tasks (press 0 when done)")
    print("2 - Complete Task")
    print("3 - View Tasks")
    print("4 - Exit")

    choice = input("Choose: ")

    if choice == "1":
        desc = input("Task description: ")
        queue.enqueue(desc)

    elif choice == "1.5":
        while True:
            desc = input("Task description: ")

            if desc == "0":
                break
            queue.enqueue(desc)

    elif choice == "2":
        done = queue.dequeue()
        if done:
            print("\nCompleted:", done.description)
            print("-" * 20)
        else:
            print("Queue is empty")
    elif choice == "3":
        print("\nCurrent Queue:")
        print("-" * 20)
        queue.display()
    elif choice == "4":
        queue.save_to_file("tasks.txt")
        break