diff --git a/Lib/test/test_dictcomps.py b/Lib/test/test_dictcomps.py
--- a/Lib/test/test_dictcomps.py
+++ b/Lib/test/test_dictcomps.py
@@ -1,54 +1,93 @@
+import unittest
 
-doctests = """
+from test import support
 
-    >>> k = "old value"
-    >>> { k: None for k in range(10) }
-    {0: None, 1: None, 2: None, 3: None, 4: None, 5: None, 6: None, 7: None, 8: None, 9: None}
-    >>> k
-    'old value'
+# For scope testing.
+g = "Global variable"
 
-    >>> { k: k+10 for k in range(10) }
-    {0: 10, 1: 11, 2: 12, 3: 13, 4: 14, 5: 15, 6: 16, 7: 17, 8: 18, 9: 19}
 
-    >>> g = "Global variable"
-    >>> { k: g for k in range(10) }
-    {0: 'Global variable', 1: 'Global variable', 2: 'Global variable', 3: 'Global variable', 4: 'Global variable', 5: 'Global variable', 6: 'Global variable', 7: 'Global variable', 8: 'Global variable', 9: 'Global variable'}
+class DictComprehensionTest(unittest.TestCase):
 
-    >>> { k: v for k in range(10) for v in range(10) if k == v }
-    {0: 0, 1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9}
+    def test_basics(self):
+        expected = {0: 10, 1: 11, 2: 12, 3: 13, 4: 14, 5: 15, 6: 16, 7: 17,
+                8: 18, 9: 19}
+        actual = {k: k + 10 for k in range(10)}
+        self.assertEqual(actual, expected)
 
-    >>> { k: v for v in range(10) for k in range(v*9, v*10) }
-    {9: 1, 18: 2, 19: 2, 27: 3, 28: 3, 29: 3, 36: 4, 37: 4, 38: 4, 39: 4, 45: 5, 46: 5, 47: 5, 48: 5, 49: 5, 54: 6, 55: 6, 56: 6, 57: 6, 58: 6, 59: 6, 63: 7, 64: 7, 65: 7, 66: 7, 67: 7, 68: 7, 69: 7, 72: 8, 73: 8, 74: 8, 75: 8, 76: 8, 77: 8, 78: 8, 79: 8, 81: 9, 82: 9, 83: 9, 84: 9, 85: 9, 86: 9, 87: 9, 88: 9, 89: 9}
+        expected = {0: 0, 1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9}
+        actual = {k: v for k in range(10) for v in range(10) if k == v}
+        self.assertEqual(actual, expected)
 
-    >>> { x: y for y, x in ((1, 2), (3, 4)) } = 5 # doctest: +IGNORE_EXCEPTION_DETAIL
-    Traceback (most recent call last):
-       ...
-    SyntaxError: ...
+    def test_scope_isolation(self):
+        k = "Local Variable"
 
-    >>> { x: y for y, x in ((1, 2), (3, 4)) } += 5 # doctest: +IGNORE_EXCEPTION_DETAIL
-    Traceback (most recent call last):
-       ...
-    SyntaxError: ...
+        expected = {0: None, 1: None, 2: None, 3: None, 4: None, 5: None,
+                    6: None, 7: None, 8: None, 9: None}
+        actual = {k: None for k in range(10)}
+        self.assertEqual(actual, expected)
+        self.assertEqual(k, "Local Variable")
 
-"""
+        expected = {9: 1, 18: 2, 19: 2, 27: 3, 28: 3, 29: 3, 36: 4, 37: 4,
+                    38: 4, 39: 4, 45: 5, 46: 5, 47: 5, 48: 5, 49: 5, 54: 6,
+                    55: 6, 56: 6, 57: 6, 58: 6, 59: 6, 63: 7, 64: 7, 65: 7,
+                    66: 7, 67: 7, 68: 7, 69: 7, 72: 8, 73: 8, 74: 8, 75: 8,
+                    76: 8, 77: 8, 78: 8, 79: 8, 81: 9, 82: 9, 83: 9, 84: 9,
+                    85: 9, 86: 9, 87: 9, 88: 9, 89: 9}
+        actual = {k: v for v in range(10) for k in range(v * 9, v * 10)}
+        self.assertEqual(k, "Local Variable")
+        self.assertEqual(actual, expected)
 
-__test__ = {'doctests' : doctests}
+    def test_scope_isolation_from_global(self):
+        expected = {0: None, 1: None, 2: None, 3: None, 4: None, 5: None,
+                    6: None, 7: None, 8: None, 9: None}
+        actual = {g: None for g in range(10)}
+        self.assertEqual(actual, expected)
+        self.assertEqual(g, "Global variable")
 
-def test_main(verbose=None):
-    import sys
-    from test import support
-    from test import test_dictcomps
-    support.run_doctest(test_dictcomps, verbose)
+        expected = {9: 1, 18: 2, 19: 2, 27: 3, 28: 3, 29: 3, 36: 4, 37: 4,
+                    38: 4, 39: 4, 45: 5, 46: 5, 47: 5, 48: 5, 49: 5, 54: 6,
+                    55: 6, 56: 6, 57: 6, 58: 6, 59: 6, 63: 7, 64: 7, 65: 7,
+                    66: 7, 67: 7, 68: 7, 69: 7, 72: 8, 73: 8, 74: 8, 75: 8,
+                    76: 8, 77: 8, 78: 8, 79: 8, 81: 9, 82: 9, 83: 9, 84: 9,
+                    85: 9, 86: 9, 87: 9, 88: 9, 89: 9}
+        actual = {g: v for v in range(10) for g in range(v * 9, v * 10)}
+        self.assertEqual(g, "Global variable")
+        self.assertEqual(actual, expected)
 
-    # verify reference counting
-    if verbose and hasattr(sys, "gettotalrefcount"):
-        import gc
-        counts = [None] * 5
-        for i in range(len(counts)):
-            support.run_doctest(test_dictcomps, verbose)
-            gc.collect()
-            counts[i] = sys.gettotalrefcount()
-        print(counts)
+    def test_global_visibility(self):
+        expected = {0: 'Global variable', 1: 'Global variable',
+                    2: 'Global variable', 3: 'Global variable',
+                    4: 'Global variable', 5: 'Global variable',
+                    6: 'Global variable', 7: 'Global variable',
+                    8: 'Global variable', 9: 'Global variable'}
+        actual = {k: g for k in range(10)}
+        self.assertEqual(actual, expected)
+
+    def test_local_visibility(self):
+        v = "Local variable"
+        expected = {0: 'Local variable', 1: 'Local variable',
+                    2: 'Local variable', 3: 'Local variable',
+                    4: 'Local variable', 5: 'Local variable',
+                    6: 'Local variable', 7: 'Local variable',
+                    8: 'Local variable', 9: 'Local variable'}
+        actual = {k: v for k in range(10)}
+        self.assertEqual(actual, expected)
+        self.assertEqual(v, "Local variable")
+
+    def test_illegal_assignment(self):
+        with self.assertRaises(SyntaxError) as err:
+            compile("{x: y for y, x in ((1, 2), (3, 4))} = 5", "<test>",
+                    "exec")
+        self.assertIn("can't assign", str(err.exception))
+
+        with self.assertRaises(SyntaxError) as err:
+            compile("{x: y for y, x in ((1, 2), (3, 4))} += 5", "<test>",
+                    "exec")
+        self.assertIn("can't assign", str(err.exception))
+
+
+def test_main():
+    support.run_unittest(__name__)
 
 if __name__ == "__main__":
-    test_main(verbose=True)
+    test_main()