ipython/ipython — pull request #1717 by bfroehle (2012-05-10 00:09:18+00:00)
Title: Define generic sys.ps{1,2,3}, for use by scripts.

Issue #123 suggests that we set `sys.ps{1,2}` to be consistent with `python`. This way scripts can tell that they are being run in an interactive session (when run using execfile or %run).

I'm not sure that I agree with this mentality, but there is likely little lost in setting the values.

Values are clearly irrelevant, but I took the constants from `IPython/zmq/frontend.py`.