FYI I just added a reasonably generic function pty_run(script, input) -> output to Lib/test/test_readline.py:120 for Issue 26870. It runs a Python script string in a child process under a pseudo-terminal. If you need to drive the curses tests with a pseudo-terminal, my code may be useful. There were about six different bugs and platform-specific quirks to work around (affecting Open BSD, Linux and various OS X versions), so I recommend learning from my experience rather than doing it all from scratch :)

Also, test_curses on Python 2 fails for me, but that is probably a separate bug.