Unbuffered stderr in Python 3

[Random832]

George Trojan <george.trojan at noaa.gov> writes:
> This does set line buffering, but does not change the behaviour:

The opposite of line buffering is not no buffering, but full
(i.e. block) buffering, that doesn't get flushed until it runs
out of space. TextIOWrapper has its own internal buffer, and its
design apparently doesn't contemplate the possibility of using
it with a raw FileIO object (which may mean that the posted code
isn't guaranteed to work) or disabling buffering.