Add Python 2 compatibility for schedule builder with functools32

- Legacy-Id: 17895

ietf/meeting/management/commands/schedule_generator.py

@@ -6,9 +6,13 @@ import datetime
 import math
 import random
 import string
-import functools
 from collections import defaultdict
 
+try:
+    from functools import lru_cache
+except ImportError:
+    from functools32 import lru_cache
+
 from django.core.management.base import BaseCommand, CommandError
 from django.db.models import Q
 
@@ -583,7 +587,7 @@ class Session(object):
         self.last_cost = cost
         return violations, cost
 
-    @functools.lru_cache(maxsize=10000)
+    @lru_cache(maxsize=10000)
     def _calculate_cost_overlapping_groups(self, overlapping_sessions):
         violations, cost = [], 0
         for other in overlapping_sessions:
@@ -603,7 +607,7 @@ class Session(object):
             cost += len(conflict_people) * self.conflict_people_penalty
         return violations, cost
 
-    @functools.lru_cache(maxsize=10000)
+    @lru_cache(maxsize=10000)
     def _calculate_cost_business_logic(self, overlapping_sessions):
         violations, cost = [], 0
         for other in overlapping_sessions:
@@ -645,8 +649,7 @@ class Session(object):
                 cost += self.business_constraint_costs['session_overlap_ad']
         return violations, cost
     
-    # TODO: Python 2 compatibility
-    @functools.lru_cache(maxsize=10000)
+    @lru_cache(maxsize=10000)
     def _calculate_cost_my_other_sessions(self, my_sessions):
         violations, cost = [], 0
         my_sessions = list(my_sessions)

requirements.txt

@@ -70,4 +70,4 @@ Unidecode>=0.4.18
 xml2rfc>=2.35.0
 xym>=0.4.4,!=0.4.7,<1.0
 #zxcvbn-python>=4.4.14		# Not needed until we do back-end password entropy validation
-
+functools32==3.2.3-2; python_version < '3'