libpython3.6-stdlib:amd64 3.6.6-1+xenial1 is not a package from the distro. You should report that issue to the PPA owner who provided these packages.
libpython3. 6-stdlib: amd64 3.6.6-1+xenial1 is not a package from the distro. You should report that issue to the PPA owner who provided these packages.