#7721: replace code that works only in 2.7+ with equivalent.
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 26aa745..b764662 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1390,8 +1390,8 @@
restricts all arguments to native C longs ("short" Python integers), and
also requires that the number of elements fit in a native C long. If a
larger range is needed, an alternate version can be crafted using the
- :mod:`itertools` module: ``islice(count(start, step),
- (stop-start+step-1)//step)``.
+ :mod:`itertools` module: ``takewhile(lambda x: x<stop, (start+i*step
+ for i in count()))``.
.. function:: zip([iterable, ...])