diff -r 5dbe3c3d014b Doc/library/itertools.rst
--- a/Doc/library/itertools.rst	Thu Nov 20 15:04:31 2014 +0100
+++ b/Doc/library/itertools.rst	Thu Nov 27 12:49:39 2014 -0800
@@ -104,7 +104,10 @@
             # accumulate([1,2,3,4,5]) --> 1 3 6 10 15
             # accumulate([1,2,3,4,5], operator.mul) --> 1 2 6 24 120
             it = iter(iterable)
+            try:
             total = next(it)
+            except StopIteration:
+                return
             yield total
             for element in it:
                 total = func(total, element)
@@ -405,7 +408,10 @@
           def _grouper(self, tgtkey):
               while self.currkey == tgtkey:
                   yield self.currvalue
-                  self.currvalue = next(self.it)    # Exit on StopIteration
+                  try:
+                      self.currvalue = next(self.it)
+                  except StopIteration:
+                      break
                   self.currkey = self.keyfunc(self.currvalue)
 
 
@@ -429,11 +435,14 @@
           # islice('ABCDEFG', 0, None, 2) --> A C E G
           s = slice(*args)
           it = iter(range(s.start or 0, s.stop or sys.maxsize, s.step or 1))
+          try:
           nexti = next(it)
           for i, element in enumerate(iterable):
               if i == nexti:
                   yield element
                   nexti = next(it)
+          except StopIteration:
+              pass
 
    If *start* is ``None``, then iteration starts at zero. If *step* is ``None``,
    then the step defaults to one.
@@ -585,12 +594,15 @@
             it = iter(iterable)
             deques = [collections.deque() for i in range(n)]
             def gen(mydeque):
+                try:
                 while True:
                     if not mydeque:             # when the local deque is empty
                         newval = next(it)       # fetch a new value and
                         for d in deques:        # load it to all the deques
                             d.append(newval)
                     yield mydeque.popleft()
+                except StopIteration:
+                    pass                            # iterator is exhausted
             return tuple(gen(d) for d in deques)
 
    Once :func:`tee` has made a split, the original *iterable* should not be