inter-operation between python and shell by using ipython script

ipython.ipy

#!/usr/bin/ipython
# vim: ft=python:
# to run it as ipython script, suffix must be .ipy
tmpfile = !mktemp
tmpfile = tmpfile[0]
files = !ls
file = open (tmpfile, "w")
file.writelines(files.n) # get it as newline separated string
file.close()
!cat $tmpfile   # refer to python variable in shell
!echo
!rm $tmpfile    # equals %sc rm $tmpfile
!echo $$HOME    # REFER to shell variable