Is Python IDLE good enough for development on a low-end computer?

Yes, especially for learning Python and working on small scripts. IDLE gives you an editor and an interactive shell without a lot of setup, so you can write code and quickly try out commands in the same tool.

It also has debugging tools, though you may eventually want a different editor for larger projects spread across many files. There's nothing wrong with starting in IDLE and switching later if you need more.

You don't need an IDE at all. A lightweight editor with syntax highlighting, such as Notepad++ or Notepad Next, plus a terminal to run Python files is a perfectly workable setup.

For simple debugging, print the values you want to inspect as the program runs. That won't replace every debugging tool, but it can get you a long way.

Vim or nano are worth a look if you're comfortable working in a terminal. They're a different experience from IDLE, though, so there's a learning curve, particularly with Vim. IDLE may be the easier place to start.

VS Code isn't necessarily heavy in every configuration. Extensions and features can affect how much it uses, so a stripped-down setup might still be an option. But if you've already removed it, trying IDLE first is a simple way to see whether it does what you need.