Darn. What if you M-x run-python and then use C-c C-c in "t.py" to send
it to the shell?
Bad news: the message
Warning (python): Your ‘python-shell-interpreter’ doesn’t seem to support readline, yet ‘python-shell-completion-native-enable’ was t and "py" is not part of the ‘python-shell-completion-native-disabled-interpreters’ list. Native completions have been disabled locally.
still appears when I M-x run-python
Good news: python shell buffer now displays
>>> python.el: native completion setup loaded
after I eval the contents of t.py. Actually, it displays the message upon loading, and completion does work. I must have believed the warning rather than checked, after install of pyreadline.
Why the message appears? It tells that completion is disabled which is not true!