zypper-aptitude from zypp:SLE-12-SP1-Branch project
Select Your Operating System
Add repository and install manually
For openSUSE Leap 42.1 Update run the following as root:
zypper addrepo https://download.opensuse.org/repositories/zypp:SLE-12-SP1-Branch/openSUSE_Leap_42.1_Update/zypp:SLE-12-SP1-Branch.repo zypper refresh zypper install zypper-aptitude