def post_parse(self):
# Add students to appropriate group
# parts (determined by surname's order)
for group_name, membership in self.students.items():
membership.sort(key=lambda o: o.student.last_name)
group_count = len(membership)
last_first = ceil(group_count/2.0)
group = Group(group_name, self.year)
self.groups.append(group)
for order, student in enumerate(membership):
student.group = group
if order < last_first:
student.part = 1
else:
student.part = 2
