New submission from Martin Panter: IOBase.close() doc says file operations raise ValueError, but it is not obvious to me that reading back the “file” buffer is a file operation.
>>> with BytesIO() as b: ... b.write(b"123") ... 3 >>> b.getvalue() Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: I/O operation on closed file. Even worse, the memoryview gets corrupted on close(): >>> b = BytesIO(b"123") >>> m = b.getbuffer() >>> b.close() >>> bytes(m) b'\x98\x02>' I also noticed that in the “io” implementation, writing to the file seems to be completely disallowed, even if it would not seem to change the size: >>> b = BytesIO(b"123") >>> m = b.getbuffer() >>> b.write(b"x") Traceback (most recent call last): File "<stdin>", line 1, in <module> BufferError: Existing exports of data: object cannot be re-sized ---------- components: IO messages: 233016 nosy: vadmium priority: normal severity: normal status: open title: BytesIO and StringIO values unavailable when closed type: behavior versions: Python 3.4 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue23099> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
