Installing Numpy + Scipy In Python 2.7 Now Fails With "runtimeerror: Python Version >= 3.5 Required"

Installing numpy and scipy from source like this (say, in a fresh Python 2.7 pyenv virtualenv): pip install numpy==1.14.6 scipy==1.0.1 --no-binary numpy,scipy gets their installer

Solution 1:

The scipy 1.0.1 installer requires numpy as a prerequisite, but the multiple installers working together end up getting the latest version of numpy unless numpy is already present.

What changed: The latest version of numpy requires Python 3.5+, hence the error message.

So even though the pip command explicitly asked to install numpy==1.14.6 scipy==1.0.1, it triggers a newer numpy installer that fails on Python 2. (The last entry in the stack trace shows numpy-1.17.1 requiring Python 3.)

The problem arises in the interaction between pip, the scipy and numpy installers, and easy_install. Details in pip issue #6945.

Workaround: Install numpy first. Then install scipy. Alternatively, the one-line install might work if you don't need the --no-binary option.

Solution 2:

I also encountered an issue where scipy was been installed through a script and it was trying to install a version 1.7.1 which required python 3.7 at least and i hand 3.6. The workaround was i installed scipy myself and the version i got was 1.5.4.