Martin Panter added the comment: >From memory, there are at least three code paths for input():
1. Fallback implementation, used when stdout is a pipe or other non-terminal 2. Default PyOS_ReadlineFunctionPointer() hook, used when stdout is a terminal: https://docs.python.org/3.5/c-api/veryhigh.html#c.PyOS_ReadlineFunctionPointer 3. Gnu Readline (or another hook installed by a C module) Arnon’s problem only seems to occur in the last two cases, when PyOS_ReadlineFunctionPointer() is used. The problem is that PyOS_ReadlineFunctionPointer() uses C <stdio.h> FILE pointers, not Python file objects. Python calls sys.stdout.fileno() to see if it can substitute the C-level stdout FILE object. Adam: I think your sys.readlinehook() proposal is independent of Arnon’s problem. We would still need some logic to decide what to pass to libraries like Gnu Readline that want a FILE pointer instead of a Python file object. The fileno() method is documented all file objects, including text files like sys.stdout. So I think implementing your own fileno() method is completely valid. One other idea that comes to mind is if Python checked if the sys.stdout object has been changed (e.g. sys.stdout != sys.__stdout__), rather than just comparing fileno() values. But I am not sure if this change is worth it. BTW if I revert the fix for Issue 24402 (I also tried 3.3.3), the problem occurs even when a custom fileno() is defined. On the other hand, Python 2’s raw_input() is not affected, presumably because it uses PyFile_AsFile() and fails immediately if stdout is a custom class. ---------- nosy: +martin.panter _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue28373> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
