Fix output encoding mismatch

[mehrdadn]

Outputting Unicode on Windows can result in an error since the default encoding for open() (cp1252) can be different from that of stdio. [1] Here we make it match that of the underlying stream.

For earlier Python versions it would also be necessary to change the default encoding for stdio to utf-8, but I avoided doing that here since the default appears to have been already changed to UTF-8 as of Python 3.7(?).

[1] This can be observed by running this in the Command Prompt:

> python -c "import os, sys; print((sys.stdout.encoding, open(os.devnull, 'w').encoding))"
('utf-8', 'cp1252')

[kavigupta]

Lgtm