todo.py

FILE_NAME = "tasks.txt"

def load_tasks():
    tasks = []
    try:
        with open(FILE_NAME, "r") as f:
            for line in f:
                task, status = line.strip().split("|")
                tasks.append({"task": task, "done": status == "1"})
    except FileNotFoundError:
        pass
    return tasks

def save_tasks(tasks):
    with open(FILE_NAME, "w") as f:
        for t in tasks:
            f.write(f"{t['task']}|{int(t['done'])}\n")

def show_tasks(tasks):
    if not tasks:
        print("No tasks available")
        return
    for i, t in enumerate(tasks, 1):
        status = "✔" if t["done"] else "✗"
        print(f"{i}. {t['task']} [{status}]")

def add_task(tasks):
    task = input("Enter task: ")
    tasks.append({"task": task, "done": False})

def mark_done(tasks):
    show_tasks(tasks)
    try:
        idx = int(input("Task number to mark done: ")) - 1
        tasks[idx]["done"] = True
    except:
        print("Invalid input")

def main():
    tasks = load_tasks()
    while True:
        print("\n1.Add  2.View  3.Done  4.Exit")
        choice = input("Choose: ")
        if choice == "1":
            add_task(tasks)
        elif choice == "2":
            show_tasks(tasks)
        elif choice == "3":
            mark_done(tasks)
        elif choice == "4":
            save_tasks(tasks)
            break
        else:
            print("Invalid choice")

main()