use // for integer division instead of /, which results in floats in python3
use // for integer division instead of /, which results in floats in python3

anubhavvardhan/qutip,zasdfgbnm/qutip,zasdfgbnm/qutip,cgranade/qutip,qutip/qutip,anubhavvardhan/qutip,cgranade/qutip,qutip/qutip