Help Lavar pay for school!

lavar-ball-scholarship-cache-sort.py

# Lavar Ball is looking for scholarships to help pay for school.
# He has 2 lists, A and B. 
# A is a cache of Lavar's scholarships as an array of primary keys.
# B is an array of scholarship objects matching Lavar's profile.
# Lavar needs to sort the objects in B based on the PKs of A, to get a new B (B_2).
# Lavar needs it done in less than O(n^2) time so he doesn't get bored and starts browsing Reddit.

# e.g. 
A = [3,139,47] # arbitrary order
B = [{pk:139,name:'Scholarship X'},{pk:47,name:'Scholarship Y'},{pk:3,name:'Scholarship Z'}]
# Solution: B_2 =  [{pk:3,name:'Scholarship Z'},{pk:47,name:'Scholarship Y'},{pk:139,name:'Scholarship Z'}]

# Current (very slow) solution.

# scholarships = list(scholarships)
scholarships = B
ranked_scholarships = A

# todo fix bottleneck 0(n^2)
for pk in user_profile.scholarship_cache:
    scholarship = [scholarship for scholarship in scholarships if scholarship['pk'] == pk]
    ranked_scholarships.extend(scholarship)
scholarships = ranked_scholarships



# Code will be implemented in Django (just FYI if it helps, but solution is platform/framework agnostic)
# A = user_profile.scholarship_cache, B = scholarships
# scholarships = Scholarship.objects.filter(pk__in=user_profile.scholarship_cache)