Add collections.NamedTuple

Lib/test/test_collections.py

@@ -0,0 +1,57 @@
+import unittest
+from test import test_support
+from collections import NamedTuple
+
+class TestNamedTuple(unittest.TestCase):
+
+    def test_factory(self):
+        Point = NamedTuple('Point', 'x y')
+        self.assertEqual(Point.__name__, 'Point')
+        self.assertEqual(Point.__doc__, 'Point(x, y)')
+        self.assertEqual(Point.__slots__, ())
+        self.assertEqual(Point.__module__, __name__)
+        self.assertEqual(Point.__getitem__, tuple.__getitem__)
+        self.assert_('__getitem__' in Point.__dict__)                       # superclass methods localized
+
+    def test_instance(self):
+        Point = NamedTuple('Point', 'x y')
+        p = Point(11, 22)
+        self.assertEqual(p, Point(x=11, y=22))
+        self.assertEqual(p, Point(11, y=22))
+        self.assertEqual(p, Point(y=22, x=11))
+        self.assertEqual(p, Point(*(11, 22)))
+        self.assertEqual(p, Point(**dict(x=11, y=22)))
+        self.assertRaises(TypeError, Point, 1)                              # too few args
+        self.assertRaises(TypeError, Point, 1, 2, 3)                        # too many args
+        self.assertRaises(TypeError, eval, 'Point(XXX=1, y=2)', locals())   # wrong keyword argument
+        self.assertRaises(TypeError, eval, 'Point(x=1)', locals())          # missing keyword argument
+        self.assertEqual(repr(p), 'Point(x=11, y=22)')
+        self.assert_('__dict__' not in dir(p))                              # verify instance has no dict
+        self.assert_('__weakref__' not in dir(p))
+
+    def test_tupleness(self):
+        Point = NamedTuple('Point', 'x y')
+        p = Point(11, 22)
+
+        self.assert_(isinstance(p, tuple))
+        self.assertEqual(p, (11, 22))                                       # matches a real tuple
+        self.assertEqual(tuple(p), (11, 22))                                # coercable to a real tuple
+        self.assertEqual(list(p), [11, 22])                                 # coercable to a list
+        self.assertEqual(max(p), 22)                                        # iterable
+        self.assertEqual(max(*p), 22)                                       # star-able
+        x, y = p
+        self.assertEqual(p, (x, y))                                         # unpacks like a tuple
+        self.assertEqual((p[0], p[1]), (11, 22))                            # indexable like a tuple
+        self.assertRaises(IndexError, p.__getitem__, 3)
+
+        self.assertEqual(p.x, x)
+        self.assertEqual(p.y, y)
+        self.assertRaises(AttributeError, eval, 'p.z', locals())
+
+
+def test_main(verbose=None):
+    test_classes = [TestNamedTuple]
+    test_support.run_unittest(*test_classes)
+
+if __name__ == "__main__":
+    test_main(verbose=True)