This is a quick note.
pip3 installing to the global site-package sometimes causes problems. In python, virtualenv helps isolate dependencies.
On Termux:
pip3 install virtualenv
# go to home dir
cd ~/
# create a fresh new venvnumpy
virtualenv venvnumpy
# activate venvnumpy
source venvnumpy/bin/activate
Now inside that venvnumpy, we can install stuff:
pip3 install --upgrade numpy scipy
pip3 install --upgrade pandas