Generalize list(seq) to work with iterators. This also generalizes list()
to no longer insist that len(seq) be defined.
NEEDS DOC CHANGES.
This is meant to be a model for how other functions of this ilk (max,
filter, etc) can be generalized similarly. Feel encouraged to grab your
favorite and convert it!
Note some cute consequences:
list(file) == file.readlines() == list(file.xreadlines())
list(dict) == dict.keys()
list(dict.iteritems()) = dict.items()
list(xrange(i, j, k)) == range(i, j, k)
diff --git a/Lib/test/test_iter.py b/Lib/test/test_iter.py
index d4b8736..5b9bf65 100644
--- a/Lib/test/test_iter.py
+++ b/Lib/test/test_iter.py
@@ -243,4 +243,36 @@
except OSError:
pass
+ # Test list()'s use of iterators.
+ def test_builtin_list(self):
+ self.assertEqual(list(SequenceClass(5)), range(5))
+ self.assertEqual(list(SequenceClass(0)), [])
+ self.assertEqual(list(()), [])
+ self.assertEqual(list(range(10, -1, -1)), range(10, -1, -1))
+
+ d = {"one": 1, "two": 2, "three": 3}
+ self.assertEqual(list(d), d.keys())
+
+ self.assertRaises(TypeError, list, list)
+ self.assertRaises(TypeError, list, 42)
+
+ f = open(TESTFN, "w")
+ try:
+ for i in range(5):
+ f.write("%d\n" % i)
+ finally:
+ f.close()
+ f = open(TESTFN, "r")
+ try:
+ self.assertEqual(list(f), ["0\n", "1\n", "2\n", "3\n", "4\n"])
+ f.seek(0, 0)
+ self.assertEqual(list(f.xreadlines()),
+ ["0\n", "1\n", "2\n", "3\n", "4\n"])
+ finally:
+ f.close()
+ try:
+ unlink(TESTFN)
+ except OSError:
+ pass
+
run_unittest(TestCase)