I can not determine where the ipython is storing its history.
a. There is no ~/.pythonhistory:
12:49:00/dashboards $ll ~/.py*
ls: /Users/steve/.py*: No such file or directory
12:49:07/dashboards $echo $PYTHONSTARTUP
12:49:43/dashboards $cat /shared/.pythonstartup
13:30:05/shared $ll ~/.ipython/profile_default/history.sqlite
-rw-r--r-- 1 steve staff 372736 Jun 3 12:48 /Users/steve/.ipython/profile_default/history.sqlite
IPython history is stored in a SQLite database located in the profile directory. By default:
Older versions (1.x) stored profile data in
~/.config/ipython, at least on platforms conforming to XDG basedir specs (i.e. most Linux distributions).
Anyway, you can locate the profile directory with:
$ ipython locate profile default
Notice that the history database is shared between IPython and IPython3, if both are installed.