/usr/include/python3.5m/numpy is in python3-numpy 1:1.12.1-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/include/python3.5m/../../lib/python3/dist-packages/numpy/core/include/numpy
/usr/include/python3.5m/../../lib/python3/dist-packages/numpy/core/include/numpy