bpo-41097: allow io.BufferIO.write() operations when there are buffer views and no buffer resize is required#21792
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websurfer5 wants to merge 1 commit intopython:mainfrom
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bpo-41097: allow io.BufferIO.write() operations when there are buffer views and no buffer resize is required#21792websurfer5 wants to merge 1 commit intopython:mainfrom
websurfer5 wants to merge 1 commit intopython:mainfrom
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…o that BytesIO objects can be written when there are one or more buffer views and a resize operation is not required
| @@ -0,0 +1,2 @@ | |||
| :func:`io.BytesIO.write` no longer raises :exc:`BufferError` when one or | |||
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It should be meth, not func.
| self.assertEqual(memio.tell(), 1) | ||
| memio.write(bufval3) # should not raise an exception | ||
| self.assertEqual(memio.getvalue(), b'????') | ||
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Please add another space (for PEP 8).
| self.assertRaises(BufferError, memio.write, bufval3) | ||
| # release the buffer view and try forcing a | ||
| # buffer resize | ||
| del buf |
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I have doubts about this del.
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io.BytesIO prevents writes when there are buffer view objects. All calls to io.BytesIO.write() raise BufferError with the message "BufferError: Existing exports of data: object cannot be re-sized" even when no resize operation is required. This patch moves the check for existing buffer views from the beginning of the write_bytes() function to the beginning of the resize_buffer() function so that writes can be performed when the output is small enough to fit within the existing buffer.
This change conforms with the behavior implied by the documentation, which merely states that the BytesIO buffer cannot be resized or closed when a view exists. The alternative to this change in behavior is to change the documentation to clarify that write operations are not allowed when there are buffer view objects.
https://bugs.python.org/issue41097