On 10/06/2012 17:41, Stephen J. Turnbull wrote:
^^^^^^^[[[[[[[[[@[@Nick Coghlan writes:
On Mon, Jun 11, 2012 at 12:34 AM, Serhiy Storchaka<storchaka@gmail.com> wrote:
open(sys.stdin.fileno()) is not guaranteed to work if the input or output have occurred before. [...]
Right, but the point of this discussion is to document the cleanest available way for an application to change these settings at *application start* (e.g. to support an "--encoding" parameter). Yes, there are potential issues if you use any of these mechanisms while there is data in the buffers,
+1
The OP's problem is a real one. His use case (the "--encoding" parameter) seems to be the most likely one in production use, so the loss of buffered data issue should rarely come up. Changing encodings on the fly offers plenty of ways to lose data besides incomplete buffers, anyway.
I am a little concerned with MRAB's report that
import sys print("hello") sys.stdout.flush() sys.stdout = open(sys.stdout.fileno(), 'w', encoding='utf-8') print("hello")
doesn't work as expected, though. (It does work for me on Mac OS X, both as above -- of course there are no '\r's in the output -- and with 'print("hello", end="\r\n")'.)
That's actually Python 3.1. From Python 3.2 it's slightly different, but still not quite right: Python 3.1: "hello\r\nhello\r\r\n" Python 3.2: "hello\nhello\r\n" Python 3.3.0a4: "hello\nhello\r\n" All on Windows.