python3-pyxdg from openSUSE:Backports:SLE-12-SP4 project

需要 standard ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/openSUSE:Backports:SLE-12-SP4/standard/openSUSE:Backports:SLE-12-SP4.repo
zypper refresh
zypper install python3-pyxdg