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_mmap.py b/Lib/test/test_mmap.py
index 0b53823..769eaed 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -306,6 +306,40 @@
m[x] = ch = chr(x & 255)
self.assertEqual(m[x], ch)
+ def test_extended_getslice(self):
+ # Test extended slicing by comparing with list slicing.
+ s = "".join(chr(c) for c in reversed(range(256)))
+ m = mmap.mmap(-1, len(s))
+ m[:] = s
+ self.assertEqual(m[:], s)
+ indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
+ for start in indices:
+ for stop in indices:
+ # Skip step 0 (invalid)
+ for step in indices[1:]:
+ self.assertEqual(m[start:stop:step],
+ s[start:stop:step])
+
+ def test_extended_set_del_slice(self):
+ # Test extended slicing by comparing with list slicing.
+ s = "".join(chr(c) for c in reversed(range(256)))
+ m = mmap.mmap(-1, len(s))
+ indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
+ for start in indices:
+ for stop in indices:
+ # Skip invalid step 0
+ for step in indices[1:]:
+ m[:] = s
+ self.assertEqual(m[:], s)
+ L = list(s)
+ # Make sure we have a slice of exactly the right length,
+ # but with different data.
+ data = L[start:stop:step]
+ data = "".join(reversed(data))
+ L[start:stop:step] = data
+ m[start:stop:step] = data
+ self.assertEquals(m[:], "".join(L))
+
def test_main():
run_unittest(MmapTests)