Issue 7686: redundant open modes 'rbb', 'wbb', 'abb' no longer work on Windows (original) (raw)

Issue7686

Created on 2010-01-13 00:28 by ivank, last changed 2022-04-11 14:56 by admin. This issue is now closed.

Messages (3)
msg97674 - (view)	Author: ivank (ivank)	Date: 2010-01-13 00:28
This probably only applies to Windows. The redundant 'b' modes still work on Linux. These worked on Windows in 2.6.4: open('test', 'rbb') open('test', 'wbb') open('test', 'abb') and possibly others. In 2.7a2, they throw ValueErrors like this: >>> open('test', 'wbb') Traceback (most recent call last): File "", line 1, in ValueError: Invalid mode ('wbb') It would be nice if the old behavior were preserved for backwards compatibility. Some programs append a 'b' indiscriminately.
msg97685 - (view)	Author: Ezio Melotti (ezio.melotti) *	Date: 2010-01-13 05:12
With 2.7 I can reproduce the issue on Windows 7 (i.e. I get a ValueError). However I'm not sure how common is to add a 'b' indiscriminately: 1) most of the times the modes are written as strings, and not generated automatically; 2) even if generated, checking if there's a 'b' is as easy as doing "if 'b' not in mode: mode = mode + 'b'". For consistency both Windows and Linux should have the same behavior, and if the extra 'b' is not so common I think it's better if both raise an error.
msg192567 - (view)	Author: Christian Heimes (christian.heimes) *	Date: 2013-07-07 14:50
For Python 2.7 we can no longer do anything about it. Any chance might break 3rd party software. Python 3.x and Python 2.7's io module don't allow redundant information. I suggest that you follow Ezio's advice and check for redundancy in your application.