Thank you for your great project!

Google always guides me to https://stackoverflow.com/a/15485265, which suggests humanize.naturalsize(). I'm ok to type in ipython, and copy & paste import humanize and humanize.naturalsize().

But it'd be more than great if this small task could be simplified in something like these ways.

$ naturalsize 8589934592
8.6 GB
$ naturalsize --binary 8589934592
8.0 GiB
$ echo 8589934592 | python -m humanize naturalsize --format "%.3f"
8.590 GB

There are tools such as numfmt, but pip install is easier for me as a Windows user. :)

I'd open a PR if I found some time for this. But I can't promise my contribution. So, I'm filing just an idea here.