I've prepared a patches for python-pyasn1 package that adds python3-pyasn1 and python3-pyasn1-modules subpackages. Attachment to follow. Note: I have already emailed the owners and offered to become a co-maintainer, so I only opened this bug to track progress.
Created attachment 698288 [details] Add python3-pyasn1 and python3-pyasn1-modules subpackages
*** This bug has been marked as a duplicate of bug 909831 ***