# [pypy-svn] pypy default: Add a test for itertools.permutations().

Tue Jan 25 17:47:51 CET 2011

```Author: Armin Rigo <arigo at tunes.org>
Branch:
Changeset: r41303:a1e45048de2c
Date: 2011-01-22 17:16 +0100
http://bitbucket.org/pypy/pypy/changeset/a1e45048de2c/

Log:	Add a test for itertools.permutations().

diff --git a/pypy/module/itertools/test/test_itertools.py b/pypy/module/itertools/test/test_itertools.py
--- a/pypy/module/itertools/test/test_itertools.py
+++ b/pypy/module/itertools/test/test_itertools.py
@@ -768,6 +768,35 @@
assert prod.next() == ()
raises (StopIteration, prod.next)

+    def test_permutations(self):
+        from itertools import permutations
+        assert list(permutations('ABCD', 2)) == [
+            ('A', 'B'),
+            ('A', 'C'),
+            ('A', 'D'),
+            ('B', 'A'),
+            ('B', 'C'),
+            ('B', 'D'),
+            ('C', 'A'),
+            ('C', 'B'),
+            ('C', 'D'),
+            ('D', 'A'),
+            ('D', 'B'),
+            ('D', 'C'),
+            ]
+        assert list(permutations(range(3))) == [
+            (0, 1, 2),
+            (0, 2, 1),
+            (1, 0, 2),
+            (1, 2, 0),
+            (2, 0, 1),
+            (2, 1, 0),
+            ]
+        assert list(permutations([])) == [()]
+        assert list(permutations([], 0)) == [()]
+        assert list(permutations([], 1)) == []
+        assert list(permutations(range(3), 4)) == []
+

class AppTestItertools27:
def setup_class(cls):
```