Add recipe to the itertools docs.
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index 98cceb7..82e1ee4 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -1285,6 +1285,21 @@
... if s:
... yield d
+>>> def combinations_with_replacement(iterable, r):
+... "combinations_with_replacement('ABC', 3) --> AA AB AC BB BC CC"
+... pool = tuple(iterable)
+... n = len(pool)
+... indices = [0] * r
+... yield tuple(pool[i] for i in indices)
+... while 1:
+... for i in reversed(range(r)):
+... if indices[i] != n - 1:
+... break
+... else:
+... return
+... indices[i:] = [indices[i] + 1] * (r - i)
+... yield tuple(pool[i] for i in indices)
+
This is not part of the examples but it tests to make sure the definitions
perform as purported.
@@ -1362,6 +1377,9 @@
>>> list(compress('abcdef', [1,0,1,0,1,1]))
['a', 'c', 'e', 'f']
+>>> list(combinations_with_replacement('abc', 2))
+[('a', 'a'), ('a', 'b'), ('a', 'c'), ('b', 'b'), ('b', 'c'), ('c', 'c')]
+
"""
__test__ = {'libreftest' : libreftest}