Improve extended slicing support in builtin types and classes. Specifically:
- Specialcase extended slices that amount to a shallow copy the same way as
is done for simple slices, in the tuple, string and unicode case.
- Specialcase step-1 extended slices to optimize the common case for all
involved types.
- For lists, allow extended slice assignment of differing lengths as long
as the step is 1. (Previously, 'l[:2:1] = []' failed even though
'l[:2] = []' and 'l[:2:None] = []' do not.)
- Implement extended slicing for buffer, array, structseq, mmap and
UserString.UserString.
- Implement slice-object support (but not non-step-1 slice assignment) for
UserString.MutableString.
- Add tests for all new functionality.
diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index c10ad86..0bb7e53 100755
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -474,6 +474,18 @@
array.array(self.typecode)
)
+ def test_extended_getslice(self):
+ # Test extended slicing by comparing with list slicing
+ # (Assumes list conversion works correctly, too)
+ a = array.array(self.typecode, self.example)
+ indices = (0, None, 1, 3, 19, 100, -1, -2, -31, -100)
+ for start in indices:
+ for stop in indices:
+ # Everything except the initial 0 (invalid step)
+ for step in indices[1:]:
+ self.assertEqual(list(a[start:stop:step]),
+ list(a)[start:stop:step])
+
def test_setslice(self):
a = array.array(self.typecode, self.example)
a[:1] = a
@@ -557,12 +569,34 @@
a = array.array(self.typecode, self.example)
self.assertRaises(TypeError, a.__setslice__, 0, 0, None)
+ self.assertRaises(TypeError, a.__setitem__, slice(0, 0), None)
self.assertRaises(TypeError, a.__setitem__, slice(0, 1), None)
b = array.array(self.badtypecode())
self.assertRaises(TypeError, a.__setslice__, 0, 0, b)
+ self.assertRaises(TypeError, a.__setitem__, slice(0, 0), b)
self.assertRaises(TypeError, a.__setitem__, slice(0, 1), b)
+ def test_extended_set_del_slice(self):
+ indices = (0, None, 1, 3, 19, 100, -1, -2, -31, -100)
+ for start in indices:
+ for stop in indices:
+ # Everything except the initial 0 (invalid step)
+ for step in indices[1:]:
+ a = array.array(self.typecode, self.example)
+ L = list(a)
+ # Make sure we have a slice of exactly the right length,
+ # but with (hopefully) different data.
+ data = L[start:stop:step]
+ data.reverse()
+ L[start:stop:step] = data
+ a[start:stop:step] = array.array(self.typecode, data)
+ self.assertEquals(a, array.array(self.typecode, L))
+
+ del L[start:stop:step]
+ del a[start:stop:step]
+ self.assertEquals(a, array.array(self.typecode, L))
+
def test_index(self):
example = 2*self.example
a = array.array(self.typecode, example)