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authorRaymond Hettinger <python@rcn.com>2004-05-08 19:49:42 (GMT)
committerRaymond Hettinger <python@rcn.com>2004-05-08 19:49:42 (GMT)
commit9d7c870c6d66c8b2e066001f31ac3037d50f7012 (patch)
treec41da1755bdc2af527581c02cf2fd2ed9781ac38 /Lib/test/test_itertools.py
parentffa5a5015a359045d7efb2c4cd0b5738c97b86ce (diff)
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SF #950057: itertools.chain doesn't "process" exceptions as they occur
Both cycle() and chain() were handling exceptions only when switching input sources. The patch makes the handle more immediate. Will backport.
Diffstat (limited to 'Lib/test/test_itertools.py')
-rw-r--r--Lib/test/test_itertools.py30
1 files changed, 30 insertions, 0 deletions
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index 73e8809..54e46e1 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -644,6 +644,36 @@ class RegressionTests(unittest.TestCase):
self.assertEqual(first, second)
+ def test_sf_950057(self):
+ # Make sure that chain() and cycle() catch exceptions immediately
+ # rather than when shifting between input sources
+
+ def gen1():
+ hist.append(0)
+ yield 1
+ hist.append(1)
+ assert False
+ hist.append(2)
+
+ def gen2(x):
+ hist.append(3)
+ yield 2
+ hist.append(4)
+ if x:
+ raise StopIteration
+
+ hist = []
+ self.assertRaises(AssertionError, list, chain(gen1(), gen2(False)))
+ self.assertEqual(hist, [0,1])
+
+ hist = []
+ self.assertRaises(AssertionError, list, chain(gen1(), gen2(True)))
+ self.assertEqual(hist, [0,1])
+
+ hist = []
+ self.assertRaises(AssertionError, list, cycle(gen1()))
+ self.assertEqual(hist, [0,1])
+
libreftest = """ Doctest for examples in the library reference: libitertools.tex