Issue #25827: Merge with 3.5

1 files changed, 11 insertions, 2 deletions

diff --git a/Lib/enum.py b/Lib/enum.py
index c28f3452a7..35a9c77935 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -1,8 +1,14 @@
 import sys
-from collections import OrderedDict
 from types import MappingProxyType, DynamicClassAttribute
 
-__all__ = ['Enum', 'IntEnum', 'unique']
+# try _collections first to reduce startup cost
+try:
+    from _collections import OrderedDict
+except ImportError:
+    from collections import OrderedDict
+
+
+__all__ = ['EnumMeta', 'Enum', 'IntEnum', 'unique']
 
 
 def _is_descriptor(obj):
@@ -476,6 +482,9 @@ class Enum(metaclass=EnumMeta):
     def __str__(self):
         return "%s.%s" % (self.__class__.__name__, self._name_)
 
+    def __bool__(self):
+        return bool(self._value_)
+
     def __dir__(self):
         added_behavior = [
                 m