feat(cli): add simple CLI todo app (add/list/remove)

Author: Golixco

intermediate/simple_todo.py

@@ -0,0 +1,139 @@
+#!/usr/bin/env python3
+"""
+Simple CLI Todo app for Hacktoberfest contribution.
+Stores tasks in a JSON file with features: add, list, done, remove, clear.
+"""
+import json
+import argparse
+from pathlib import Path
+from datetime import datetime
+
+DATA_FILE = Path("tasks.json")
+
+
+def load_tasks() -> list:
+    """
+    Load and return the list of tasks from the JSON file.
+    Returns an empty list if the file does not exist or is invalid.
+    """
+    if not DATA_FILE.exists():
+        return []
+    try:
+        return json.loads(DATA_FILE.read_text())
+    except json.JSONDecodeError:
+        # Warn the user and reset tasks if JSON is invalid.
+        print("Warning: tasks.json is corrupted or not valid JSON. Resetting tasks list.")
+        return []
+
+
+def save_tasks(tasks: list) -> None:
+    """
+    Save the list of tasks to the JSON file with pretty formatting.
+    """
+    DATA_FILE.write_text(json.dumps(tasks, indent=2, sort_keys=False))
+
+
+def add_task(text: str) -> None:
+    """
+    Add a new task with the given text to the list.
+    """
+    tasks = load_tasks()
+    tasks.append({
+        "id": int(datetime.now().timestamp()),
+        "text": text,
+        "done": False,
+        "created": datetime.now().isoformat()
+    })
+    save_tasks(tasks)
+    print("Added:", text)
+
+
+def list_tasks() -> None:
+    """
+    List all tasks with their status. Uncompleted tasks show [ ] and done tasks show [✓].
+    """
+    tasks = load_tasks()
+    if not tasks:
+        print('No tasks. Add one using: todo.py add "Buy milk"')
+        return
+    for i, t in enumerate(tasks, 1):
+        status = "✓" if t.get("done") else " "
+        print(f"{i}. [{status}] {t.get('text')} (id:{t.get('id')})")
+
+
+def mark_done(index: int) -> None:
+    """
+    Mark the task at the given 1-based index as done.
+    """
+    tasks = load_tasks()
+    if index < 1 or index > len(tasks):
+        print("Invalid task number.")
+        return
+    tasks[index - 1]["done"] = True
+    save_tasks(tasks)
+    print("Marked done:", tasks[index - 1]["text"])
+
+
+def remove_task(index: int) -> None:
+    """
+    Remove the task at the given 1-based index.
+    """
+    tasks = load_tasks()
+    if index < 1 or index > len(tasks):
+        print("Invalid task number.")
+        return
+    removed = tasks.pop(index - 1)
+    save_tasks(tasks)
+    print("Removed:", removed["text"])
+
+
+def clear_tasks() -> None:
+    """
+    Clear all tasks.
+    """
+    save_tasks([])
+    print("All tasks cleared.")
+
+
+def parse_args() -> argparse.Namespace:
+    """
+    Parse command-line arguments and return the parsed namespace.
+    """
+    parser = argparse.ArgumentParser(prog="todo.py", description="Simple CLI todo app")
+    subparsers = parser.add_subparsers(dest="cmd")
+
+    # Add command
+    sp_add = subparsers.add_parser("add", help="Add a new task")
+    sp_add.add_argument("text", nargs="+", help="Task text")
+    # List command
+    sp_list = subparsers.add_parser("list", help="List all tasks")
+    # Done command
+    sp_done = subparsers.add_parser("done", help="Mark a task as done")
+    sp_done.add_argument("number", type=int, help="Task index to mark as done (from list)")
+    # Remove command
+    sp_rm = subparsers.add_parser("remove", help="Remove a task")
+    sp_rm.add_argument("number", type=int, help="Task index to remove (from list)")
+    # Clear command
+    sp_clear = subparsers.add_parser("clear", help="Remove all tasks")
+
+    return parser.parse_args()
+
+
+def main() -> None:
+    args = parse_args()
+    if args.cmd == "add":
+        add_task(" ".join(args.text))
+    elif args.cmd == "list" or args.cmd is None:
+        list_tasks()
+    elif args.cmd == "done":
+        mark_done(args.number)
+    elif args.cmd == "remove":
+        remove_task(args.number)
+    elif args.cmd == "clear":
+        clear_tasks()
+    else:
+        print("Unknown command. Use add/list/done/remove/clear")
+
+
+if __name__ == "__main__":
+    main()