if you're not absolutely tied to the python libraries--which makes things a little complicated--might be easier to use BioPerl perl package instead. depending on which platform you're on, adding the package or specific module from it to perl is done a little differently. at least i think that the BioPerl package has what you're looking for, i.e. Bio::PhyloNetwork module in it.
i think that's the easiest way..rather than trying to call python routines from perl or worse doing IPC between a python and perl program. sorry about the acronym..it's short though :)
if you let us know if you're on windows/linux/unix/mac etc and which version of perl you're on, then someone might help with installing your preferred module for perl.
browse/search in cpan for phylogenetic and have a look at the documentation there, to see if a module suits.