Problem with emacs and input() using iPython 3.6.4

Question

I am using emacs 25.2.1

Look at the following simple code:

import sys

def yes_no_barrier(message):
    print(message + ' (yes/no): ')
    while 1:
        s=str(input(message + ' (yes/no): '))
        if s == 'yes':
            return 'yes'
        if s == 'no':
            return 'no'
        print('please enter yes or no')

yes_no_barrier('Are you tall?')

I tried to run the code in a real terminal (Python 3.6.4) and it was worked. Then I tried to run it inside emacs, first using C-c C-p for opening a Python console, and then, from the .py buffer, pressing C-c C-c.

I tried no and the code worked, I then tried yes and other strings and the Python buffer froze, forcing me to press C-g. I have no clue what there is special with no except for being shorter than the word yes.

Since I was always getting the same strange behaviour I dug the web and I tried random stuff, finally solving the issue.

Here there is the full Python configuration which fixed the issue, not sure which part did it.

;I also installed from list-packages python-mode
(require 'python)
(add-hook 'python-mode-hook
      (lambda ()
        (setq indent-tabs-mode t)
        (setq tab-width 4)
        (setq python-indent 4)))

(setq scroll-down-aggressively 1)

(defun python-shell-parse-command ()
   "Return the string used to execute the inferior Python process."
   "/usr/bin/python3 -i")

(setq py-python-command "python3")
(setq py-shell-name "python3")
(setq python-shell-interpreter "python3")

I was happy with this magic code, but I had to switch to IPython (6.2.1, still using Python 3.6.4) since I wanted to solve this other problem, described here.

That problem was solved but now I have back the same problem with input() which I described before: no works but yes makes the console freeze.

I tried the obvious modifications to my configuration, which are listed here:

(setenv "IPY_TEST_SIMPLE_PROMPT" "1") ;for fixing a problem with IPython not showing correctly

(setq python-shell-interpreter "/usr/local/bin/ipython"
   python-shell-interpreter-args "--profile=dev -i")

(defun python-shell-parse-command () "/usr/local/bin/ipython
--profile=dev -i")

(setq py-python-command "ipython")
(setq py-shell-name "ipython")
(setq python-shell-interpreter "ipython")

But the error this time is not disappearing.

Can you help me, please? Does the code work in your emacs?

EDIT1: I just realised that the problem does not arise when I press return but when I type the third letter of a word, so if I type yes, then I will not be able to use the console anymore. For instance I will not be able to type backspace and I will be forced to press C-g to send a keyboard interrupt and make the console usable again.

EDIT2: I removed the line (require 'python) and now I type M-x ipython. The console that will appear works and I can send commands to it with C-c C-c. The console that I open with C-c C-p does not work. So I can consider solved my problem.

Answer 1

AFAIK this is caused by an change of IPython which seems not to accept multiline pasting any more.

Here is some info: https://github.com/ipython/ipython/issues/9816