New submission from R. David Murray <rdmur...@bitdance.com>: The python 3.x io library appears to allow mixing calls to __next__ and calls to readline. As another consequence, where previously it was necessary to use 'readline' to read single lines from a pipe without blocking waiting for a buffer fill, now one can apparently use 'for'.
Reading the code in io.py, it seems as though this is intentional: readline and __next__ use the same buffer, and the method on TextIOWrapper that fills the buffer calls 'read1', which in the one place where it has a docstring says that only as much data as is available is read, in contrast to 'read', which reads exactly n bytes (to EOF). Assuming this is the intended behavior, it should be documented, and if they do not exist (I didn't see any) tests should be added to confirm the behavior. If this behavior is an implementation artifact, then this should be documented so that code is less likely to depend on it. Once I know whether or not this behavior _should_ be part of the test suite, I'll be happy to work on doc and test patches. ---------- components: Library (Lib) messages: 82499 nosy: bitdancer severity: normal status: open title: document expected/required behavior of 3.x io subsystem with respect to buffering type: behavior versions: Python 3.0, Python 3.1 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue5323> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
