how to configure python.el for emacs to use python3 shell?

Question

I am new to emacs. I installed emacs24 which has a built-in python mode(python.el). I cannot find this file and don't know how to configure it to use python3 shell (it's using python2.7 as default). Thannks

Answer 1

M-x customize-variable RET python-shell-interpreter RET

Set it to python3. Afterwards M-x run-python RET should open a Python3 shell.

If not working yet, check $PATH, make sure the directory holding python3 executable appears.