DHV

Back in the very early days of my involvement with Textualize, while looking for fun things to build to test out the framework and find problems with it, I created textual-astview. The idea was pretty simple: exercise Textual's Tree widget by using it to display the output of Python's abstract syntax tree module.

While the code still works, Textual has moved on a lot, as has my approach to building applications with Textual, and so I've been wanting to do a ground-up rewrite of it. At the same time I was also thinking that it might be interesting to build a tool that provides other ways of understanding how your Python source gets turned into runnable code; with this in mind I've ended up building a terminal-based application called DHV.

The idea is pretty straightforward: you type in, paste in, or load up, Python code, and you get a real-time display of what the resulting bytecode and abstract syntax tree would be.

If you've ever wondered what a particular bit of code looks like under the hood, or wondered if one particular approach to a problem is "more efficient"¹ than another, or just wondered to yourself if 1+1 ends up being a complex operation or simply gets turned into 2, this tool might be useful to experiment and see.

As of now DHV only works with Python 3.13. The main reason for this is that the Python dis module is a bit of a moving target and has had some noticeable interface changes over the past few versions. When I find some time I might work on making DHV a little more backward-compatible. But for now keep this in mind: when you're looking at the results for some code you're looking at what Python 3.13 (or later) would do, earlier Pythons may differ.

DHV is licensed GPL-3.0 and available via GitHub and also via PyPI. If you have an environment that has pipx installed you should be able to get up and going with:

pipx install dhv

If you're a fan of uv and friends you can install it like this:

uv tool install --python 3.13 dhv