Wolfgang Maier <wolfgang.ma...@biologie.uni-freiburg.de> writes: > Standard I/O streams are line-buffered only if interactive (i.e., > connected to a console), but block-buffered otherwise.
That's not appropriate for stderr, nor is it justified by the argument that Terry Reedy cited earlier. I had assumed he was making an implicit claim that stderr is _always_ line-buffered, _even if_ it is not interactive. > What does sys.stderr.isatty() return? There are many situations in which a nominally interactive process might not have a "tty" for stderr on MS Windows. In an Emacs M-x shell buffer, in a cygwin terminal (for a non-cygwin python), etc. -- https://mail.python.org/mailman/listinfo/python-list
