Dump out a grouped list of the licences of the installed packages

dump_licences.py

"""
This gist should allow you to print a dictionary of licence types that you have installed
with a list the packages using each licence.
"""
from __future__ import print_function
import pip
import collections

info = [i for i in pip.commands.show.search_packages_info([  # takes a list of the names as a parameter
  d.project_name for d in pip.utils.get_installed_distributions() # This should give us a list of the installed package names
])]
pkglicence = {i['name']:i['license'] for i in info}
licdict = collections.defaultdict(list)

for name, license in pkglicence.iteritems():
    licdict[license].append(name)