I have upgrade my pip.
sudo pip install --upgrade pip
And used
sudo pip install openopt
its say
Collecting sortedcontainers
Processing ./Library/Caches/pip/wheels/e6/b1/a6/9719530228e258eba904501fef99d5d85c80d52bd8f14438a3/setproctitle-1.1.10-cp27-cp27m-macosx_10_15_x86_64.whl
Installing collected packages: sortedcontainers, setproctitle, openopt Successfully installed openopt-0.5629 setproctitle-1.1.10 sortedcontainers-2.1.0
from openopt import QP
ModuleNotFoundError: No module named 'openopt'