For SLE 15 SP4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:katello/SLE_15_SP4/systemsmanagement:katello.repo
zypper refresh
zypper install python-six
For SLE 15 SP3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:katello/SLE_15_SP3/systemsmanagement:katello.repo
zypper refresh
zypper install python-six
For SLE 15 SP2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:katello/SLE_15_SP2/systemsmanagement:katello.repo
zypper refresh
zypper install python-six
For SLE 15 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:katello/SLE_15/systemsmanagement:katello.repo
zypper refresh
zypper install python-six