cpython/Lib/test/test_buffer.py
Thomas Wouters 3ccec68a05 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.
2007-08-28 15:28:19 +00:00

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Python

"""Unit tests for buffer objects.
For now, tests just new or changed functionality.
"""
import unittest
from test import test_support
class BufferTests(unittest.TestCase):
def test_extended_getslice(self):
# Test extended slicing by comparing with list slicing.
s = "".join(chr(c) for c in list(range(255, -1, -1)))
b = buffer(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(b[start:stop:step],
s[start:stop:step])
def test_main():
test_support.run_unittest(BufferTests)
if __name__ == "__main__":
test_main()