diff --git a/Lib/test/seq_tests.py b/Lib/test/seq_tests.py
index aeb15c0..89996a3 100644
--- a/Lib/test/seq_tests.py
+++ b/Lib/test/seq_tests.py
@@ -5,6 +5,85 @@
 import unittest
 from test import test_support
 
+# Various iterables
+# This is used for checking the constructor (here and in test_deque.py)
+def iterfunc(seqn):
+    'Regular generator'
+    for i in seqn:
+        yield i
+
+class Sequence:
+    'Sequence using __getitem__'
+    def __init__(self, seqn):
+        self.seqn = seqn
+    def __getitem__(self, i):
+        return self.seqn[i]
+
+class IterFunc:
+    'Sequence using iterator protocol'
+    def __init__(self, seqn):
+        self.seqn = seqn
+        self.i = 0
+    def __iter__(self):
+        return self
+    def next(self):
+        if self.i >= len(self.seqn): raise StopIteration
+        v = self.seqn[self.i]
+        self.i += 1
+        return v
+
+class IterGen:
+    'Sequence using iterator protocol defined with a generator'
+    def __init__(self, seqn):
+        self.seqn = seqn
+        self.i = 0
+    def __iter__(self):
+        for val in self.seqn:
+            yield val
+
+class IterNextOnly:
+    'Missing __getitem__ and __iter__'
+    def __init__(self, seqn):
+        self.seqn = seqn
+        self.i = 0
+    def next(self):
+        if self.i >= len(self.seqn): raise StopIteration
+        v = self.seqn[self.i]
+        self.i += 1
+        return v
+
+class IterNoNext:
+    'Iterator missing next()'
+    def __init__(self, seqn):
+        self.seqn = seqn
+        self.i = 0
+    def __iter__(self):
+        return self
+
+class IterGenExc:
+    'Test propagation of exceptions'
+    def __init__(self, seqn):
+        self.seqn = seqn
+        self.i = 0
+    def __iter__(self):
+        return self
+    def next(self):
+        3 // 0
+
+class IterFuncStop:
+    'Test immediate stop'
+    def __init__(self, seqn):
+        pass
+    def __iter__(self):
+        return self
+    def next(self):
+        raise StopIteration
+
+from itertools import chain, imap
+def itermulti(seqn):
+    'Test multiple tiers of iterators'
+    return chain(imap(lambda x:x, iterfunc(IterGen(Sequence(seqn)))))
+
 class CommonTest(unittest.TestCase):
     # The type to be tested
     type2test = None
@@ -40,6 +119,17 @@
         vv = self.type2test(s)
         self.assertEqual(len(vv), len(s))
 
+        # Create from various iteratables
+        for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):
+            for g in (Sequence, IterFunc, IterGen,
+                      itermulti, iterfunc):
+                self.assertEqual(self.type2test(g(s)), self.type2test(s))
+            self.assertEqual(self.type2test(IterFuncStop(s)), self.type2test())
+            self.assertEqual(self.type2test(c for c in "123"), self.type2test("123"))
+            self.assertRaises(TypeError, self.type2test, IterNextOnly(s))
+            self.assertRaises(TypeError, self.type2test, IterNoNext(s))
+            self.assertRaises(ZeroDivisionError, self.type2test, IterGenExc(s))
+
     def test_truth(self):
         self.assert_(not self.type2test())
         self.assert_(self.type2test([42]))
diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py
index 61919cb..a562922 100644
--- a/Lib/test/test_deque.py
+++ b/Lib/test/test_deque.py
@@ -1,6 +1,6 @@
 from collections import deque
 import unittest
-from test import test_support
+from test import test_support, seq_tests
 from weakref import proxy
 import copy
 import cPickle as pickle
@@ -378,93 +378,17 @@
             d.append(1)
             gc.collect()
 
-def R(seqn):
-    'Regular generator'
-    for i in seqn:
-        yield i
-
-class G:
-    'Sequence using __getitem__'
-    def __init__(self, seqn):
-        self.seqn = seqn
-    def __getitem__(self, i):
-        return self.seqn[i]
-
-class I:
-    'Sequence using iterator protocol'
-    def __init__(self, seqn):
-        self.seqn = seqn
-        self.i = 0
-    def __iter__(self):
-        return self
-    def next(self):
-        if self.i >= len(self.seqn): raise StopIteration
-        v = self.seqn[self.i]
-        self.i += 1
-        return v
-
-class Ig:
-    'Sequence using iterator protocol defined with a generator'
-    def __init__(self, seqn):
-        self.seqn = seqn
-        self.i = 0
-    def __iter__(self):
-        for val in self.seqn:
-            yield val
-
-class X:
-    'Missing __getitem__ and __iter__'
-    def __init__(self, seqn):
-        self.seqn = seqn
-        self.i = 0
-    def next(self):
-        if self.i >= len(self.seqn): raise StopIteration
-        v = self.seqn[self.i]
-        self.i += 1
-        return v
-
-class N:
-    'Iterator missing next()'
-    def __init__(self, seqn):
-        self.seqn = seqn
-        self.i = 0
-    def __iter__(self):
-        return self
-
-class E:
-    'Test propagation of exceptions'
-    def __init__(self, seqn):
-        self.seqn = seqn
-        self.i = 0
-    def __iter__(self):
-        return self
-    def next(self):
-        3 // 0
-
-class S:
-    'Test immediate stop'
-    def __init__(self, seqn):
-        pass
-    def __iter__(self):
-        return self
-    def next(self):
-        raise StopIteration
-
-from itertools import chain, imap
-def L(seqn):
-    'Test multiple tiers of iterators'
-    return chain(imap(lambda x:x, R(Ig(G(seqn)))))
-
-
 class TestVariousIteratorArgs(unittest.TestCase):
 
     def test_constructor(self):
         for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):
-            for g in (G, I, Ig, S, L, R):
+            for g in (seq_tests.Sequence, seq_tests.IterFunc,
+                      seq_tests.IterGen, seq_tests.IterFuncStop,
+                      seq_tests.itermulti, seq_tests.iterfunc):
                 self.assertEqual(list(deque(g(s))), list(g(s)))
-            self.assertRaises(TypeError, deque, X(s))
-            self.assertRaises(TypeError, deque, N(s))
-            self.assertRaises(ZeroDivisionError, deque, E(s))
+            self.assertRaises(TypeError, deque, seq_tests.IterNextOnly(s))
+            self.assertRaises(TypeError, deque, seq_tests.IterNoNext(s))
+            self.assertRaises(ZeroDivisionError, deque, seq_tests.IterGenExc(s))
 
     def test_iter_with_altered_data(self):
         d = deque('abcdefg')