May 03 2024 Playing with rich

One of the things I do as a side project for Freexian is to work on various bits of business automation: accounting tools, programs to help contributors report their hours, invoicing, that kind of thing. While it’s not quite my usual beat, this makes quite a good side project as the tools involved are mostly rather sensible and easy to deal with (Python, git, ledger, that sort of thing) and it’s the kind of thing where I can dip into it for a day or so a week and feel like I’m making useful contributions. The logic can be quite complex, but there’s very little friction in the tools themselves.

A recent case where I did run into some friction in the tools was with some commands that need to present small amounts of tabular data on the terminal, using OSC 8 hyperlinks if the terminal supports them: think customer-related information with some links to issues. One of my colleagues had previously done this using a hack on top of texttable, which was perfectly fine as far as it went. However, now I wanted to be able to add multiple links in a single table cell in some cases, and that was really going to stretch the limits of that approach: working out the width of the displayed text in the cell was going to take an annoying amount of bookkeeping.

I started looking around to see whether any other approaches might be easier, without too much effort (remember that “a day or so a week” bit above). ansiwrap looked somewhat promising, but it isn’t currently packaged in Debian, and it would have still left me with the problem of figuring out how to integrate it into texttable, which looked like it would be quite complicated. Then I remembered that I’d heard good things about rich, and thought I’d take a look.

rich turned out to be exactly what I wanted. Instead of something like this based on the texttable hack above:

import shutil
from pyxian.texttable import UrlTable

termsize = shutil.get_terminal_size((80, 25))
table = UrlTable(max_width=termsize.columns)
table.set_deco(UrlTable.HEADER)
table.set_cols_align(["l"])
table.set_cols_dtype(["u"])
table.add_row(["Issue"])
table.add_row([(issue_url, f"#{issue_id}")]
print(table.draw())

… now I can do this instead:

import rich
from rich import box
from rich.table import Table

table = Table(box=box.SIMPLE)
table.add_column("Issue")
table.add_row(f"[link={issue_url}]#{issue_id}[/link]")
rich.print(table)

While this is a little shorter, the real bonus is that I can now just put multiple [link] tags in a single string, and it all just works. No ceremony. In fact, once the relevant bits of code passed type-checking (since the real code is a bit more complex than the samples above), it worked first time. It’s a pleasure to work with a library like that.

It looks like I’ve only barely scratched the surface of rich, but I expect I’ll reach for it more often now.