Numpy install woes

Recently I’ve started a project to look at tracking stocks combined with  company sentiment – utilising Python running on a little Raspberry Pi. I’ll link to the detailed project posts at a later point.

Anyway the first hurdle I’ve hit was getting NumPy to install correctly with the usual pip install giving the following error when NumPy is called…

Importing the multiarray numpy extension module failed. Most
likely you are trying to import a failed build of numpy.
If you’re working with a numpy git repo, try `git clean -xdf` (removes all
files not under version control). Otherwise reinstall numpy.

Original error was: cannot open shared object file: No such file or directory

ERROR: Command errored out with exit status 1: /usr/bin/python3 /usr/local/lib/python3.7/dist-packages/pip/_vendor/pep517/ prepare_metadata_for_build_wheel /tmp/tmpumibpogm Check the logs for full command output.

I tried a couple of things to fix this…

  1. Repeating the install and specifying the upgrade flag.
    sudo pip3 install -U numpy
    Note -U = –upgrade
  2. Uninstalling and re-installing NumPy and Setuptools.
    sudo pip3 uninstall -y numpy
    sudo pip3 uninstall -y setuptools
    sudo pip3 install -U setuptools
    sudo pip3 install -U numpy
    Note -y = –yes Don’t ask for confirmation of uninstall deletions.
  3. The uninstall of NumPy didn’t work so I moved to apt-get:-
    sudo apt-get remove python-numpy
    Which did the trick…

But to know avail.
So after a little light browsing I came up with an answer – not all of the NumPy dependencies had been installed. Ineed to run 

sudo apt-get install python-dev libatlas-base-dev

Which then allowed NumPy to be reinstalled and worked a treat.