def testSortingRepeatedScalarFieldsCustomComparator(self, message_module):
    """Check some different types with custom comparator."""
    message = message_module.TestAllTypes()

    message.repeated_int32.append(-3)
    message.repeated_int32.append(-2)
    message.repeated_int32.append(-1)
    message.repeated_int32.sort(key=abs)
    self.assertEqual(message.repeated_int32[0], -1)
    self.assertEqual(message.repeated_int32[1], -2)
    self.assertEqual(message.repeated_int32[2], -3)

    message.repeated_string.append('aaa')
    message.repeated_string.append('bb')
    message.repeated_string.append('c')
    message.repeated_string.sort(key=len)
    self.assertEqual(message.repeated_string[0], 'c')
    self.assertEqual(message.repeated_string[1], 'bb')
    self.assertEqual(message.repeated_string[2], 'aaa')
Check some different types with custom comparator.
deps/protobuf/python/google/protobuf/internal/message_test.py