The tarfile module supports arbitrary compressions by using the stream mode. You only need to use a third-party library which provides zstd support.

Recent versions of the tar utility has options to explicit support of new compressions: --lzip, --lzma, --lzop, --zstd, so corresponding modes can be added to the tarfile module. But it needs to include the support of these compressions in the stdlib. It should be discussed on the Python-ideas mailing list.

https://mail.python.org/mailman3/lists/python-ideas.python.org/