Build a command-line to-do list app

Here’s a complete command-line To-Do List app in Python. It allows users to add, list, complete, and delete tasks using a simple terminal interface.

python
CopyEdit
import os
import json

TODO_FILE = "todo_list.json"

def load_tasks():
    if not os.path.exists(TODO_FILE):
        return []
    with open(TODO_FILE, "r") as file:
        return json.load(file)

def save_tasks(tasks):
    with open(TODO_FILE, "w") as file:
        json.dump(tasks, file, indent=2)

def list_tasks(tasks):
    if not tasks:
        print("No tasks in your to-do list.")
    else:
        for i, task in enumerate(tasks, 1):
            status = "✓" if task["completed"] else "✗"
            print(f"{i}. [{status}] {task['title']}")

def add_task(tasks, title):
    tasks.append({"title": title, "completed": False})
    save_tasks(tasks)
    print(f"Added task: {title}")

def complete_task(tasks, index):
    if 0 <= index < len(tasks):
        tasks[index]["completed"] = True
        save_tasks(tasks)
        print(f"Marked task {index + 1} as completed.")
    else:
        print("Invalid task number.")

def delete_task(tasks, index):
    if 0 <= index < len(tasks):
        removed = tasks.pop(index)
        save_tasks(tasks)
        print(f"Deleted task: {removed['title']}")
    else:
        print("Invalid task number.")

def show_menu():
    print("nTo-Do List App")
    print("1. List tasks")
    print("2. Add task")
    print("3. Complete task")
    print("4. Delete task")
    print("5. Exit")

def main():
    tasks = load_tasks()
    while True:
        show_menu()
        choice = input("Enter your choice (1-5): ").strip()
        if choice == "1":
            list_tasks(tasks)
        elif choice == "2":
            title = input("Enter task title: ").strip()
            if title:
                add_task(tasks, title)
        elif choice == "3":
            list_tasks(tasks)
            try:
                index = int(input("Enter task number to complete: ")) - 1
                complete_task(tasks, index)
            except ValueError:
                print("Please enter a valid number.")
        elif choice == "4":
            list_tasks(tasks)
            try:
                index = int(input("Enter task number to delete: ")) - 1
                delete_task(tasks, index)
            except ValueError:
                print("Please enter a valid number.")
        elif choice == "5":
            print("Goodbye!")
            break
        else:
            print("Invalid choice. Please select a valid option.")

if __name__ == "__main__":
    main()

How it works:

• Stores tasks in todo_list.json.

• Tasks are represented as dictionaries with "title" and "completed" status.

• Provides a simple menu to interact via the terminal.

You can run it using:

bash
CopyEdit
python todo.py

Let me know if you’d like a version using a database, GUI, or a different language.