To get the size of archives and folders:
os.stat(filename).st_size # for folders you have to use it together with os.walk()

To get the list of files inside an archive I use the zipfile, rarfile and tarfile modules.
For the file type, I either extract the extension from the name or I use a bash command via subprocess:file --mime-type filepath
subprocess is used if there is no extension (as often happens with text files).

I preferred to use subprocess to avoid having to increase the number of dependencies needed.

.txt or plain text files without extension are supported.

instructions reference INSTALL.sh but that’s not in the source? Maybe only in the release tarball?

I added it to the repository: https://github.com/Nyre221/dolphin-quick-view/tree/main/package creation

does it clear the user’s entire clipboard history each time it’s run?

I made some changes and now it doesn’t delete all the history, only the last thing copied (afterwards try to restore it but it doesn’t work if you copied a folder or file): https://github.com/Nyre221/dolphin-quick-view/blob/main/package creation/quick_view_package/dolphin_quick_view_shortcut.sh

this is caused by dolphin’s limitations and there’s not much I can do about it.

would it make sense to package this up for PyPI, with system deps being checked for and reported from within python? If so, are you interested in pull requests?

I don’t think it makes much sense for this application.
For now I’m trying to integrate the modules inside a .pyz and eliminate the use of pip: https://github.com/Nyre221/dolphin-quick-view/issues/10