Sync-up minor code edits with the default branch.

Lib/random.py

@@ -42,7 +42,7 @@ from types import MethodType as _MethodType, BuiltinMethodType as _BuiltinMethod
 from math import log as _log, exp as _exp, pi as _pi, e as _e, ceil as _ceil
 from math import sqrt as _sqrt, acos as _acos, cos as _cos, sin as _sin
 from os import urandom as _urandom
-import collections as _collections
+from collections import Set as _Set, Sequence as _Sequence
 from hashlib import sha512 as _sha512
 
 __all__ = ["Random","seed","random","uniform","randint","choice","sample",
@@ -293,10 +293,10 @@ class Random(_random.Random):
         # preferred since the list takes less space than the
         # set and it doesn't suffer from frequent reselections.
 
-        if isinstance(population, _collections.Set):
+        if isinstance(population, _Set):
             population = tuple(population)
-        if not isinstance(population, _collections.Sequence):
-            raise TypeError("Population must be a sequence or Set.  For dicts, use list(d).")
+        if not isinstance(population, _Sequence):
+            raise TypeError("Population must be a sequence or set.  For dicts, use list(d).")
         randbelow = self._randbelow
         n = len(population)
         if not 0 <= k <= n: