Add usage note

diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 68a6c8307556e71cf386d2b284c055392556f0d9..d1d1188106e4691eb0d7109eb920e62b0937e557 100644 (file)
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -496,6 +496,11 @@ loops that truncate the stream.
               for i in range(times):
                   yield object
 
+   A common use for *repeat* is to supply a stream of constant values to *map*
+   or *zip*::
+
+      >>> list(map(pow, range(10), repeat(2)))
+      [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
 
 .. function:: starmap(function, iterable)