Feature or enhancement

Proposal:

Currently,tarfile.open() doesn't support specifying a compression level / preset when usingmode="w|xz". Technically this is documented (via not listingw|xz among the modes supporting eithercompresslevel orpreset argument), it's kinda surprising (to the point of me thinking thatw|xz takescompresslevel instead ofpreset, since the latter threw aTypeError — and then being surprised that the default compression level was used), and quite limiting that you can't set the preset while using stream mode. On top of that, there does not seem to be any technical limitation preventing us from doing that.

I'm working on a pull request to add that option.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-133005: Supporttarfile.open(mode="w|xz", preset=...) #133007