Examples for named tuple subclassing should include __slots__

1 files changed, 3 insertions, 1 deletions

diff --git a/Lib/collections.py b/Lib/collections.py
index a234b44..47b0397 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -118,17 +118,19 @@ if __name__ == '__main__':
 
     # test and demonstrate ability to override methods
     class Point(namedtuple('Point', 'x y')):
+        __slots__ = ()
         @property
         def hypot(self):
             return (self.x ** 2 + self.y ** 2) ** 0.5
         def __str__(self):
             return 'Point: x=%6.3f y=%6.3f hypot=%6.3f' % (self.x, self.y, self.hypot)
 
-    for p in Point(3,4), Point(14,5), Point(9./7,6):
+    for p in Point(3, 4), Point(14, 5/7.):
         print p
 
     class Point(namedtuple('Point', 'x y')):
         'Point class with optimized _make() and _replace() without error-checking'
+        __slots__ = ()
         _make = classmethod(tuple.__new__)
         def _replace(self, _map=map, **kwds):
             return self._make(_map(kwds.get, ('x', 'y'), self))