Can't get IPython to run Python 2.7 instead of 3.5 -

i'm on arch linux trying make ipython run python 2.7 instead of python 3.5. edited /usr/bin/ipython, looks this:

#!/usr/bin/python # script automatically generated setup.py if __name__ == '__main__':     ipython import start_ipython     start_ipython() 

and on first line substituted

#!/usr/bin/python  

for

#!/usr/bin/python2.7 

but after when tried run ipython message:

traceback (most recent call last):   file "/usr/bin/ipython", line 4, in <module>     ipython import start_ipython importerror: no module named ipython 

i'd know have able run python2.7 when type ipython , run python3 when type ipython3