Hi everyone! 👋
I got an email from someone pretty recently who wanted to setup a dev environment for SciPy. He had made changes to the source code of SciPy and now wanted to test if his changes were working or not. He had gotten so far without actually testing the code. In this post I will share details on how to setup a dev environment the right way. I will focus mainly on Mac OS.
Firstly, go to the GitHub repo and try to figure out the dependencies for the project. Normally they are listed in the readme file. If they are not listed there then you just try installing the package/libary and the errors in the terminal will give you a clue as to what you are missing. I did that and figured out that I needed Fortran compiler, Cython and NumPy.
Let’s start with Fortran:
brew install gcc
Now create a new folder and setup a virtualenv there:
mkdir ~/dev cd ~/dev python -m venv env
Activate the virtualenv:
Now install Cython and NumPy:
pip install cython pip install numpy
Now clone SciPy:
git clone firstname.lastname@example.org:scipy/scipy.git
And finally install SciPy in development mode:
cd scipy python setup.py develop
Normally if you are installing a Python package using the
setup.py file, you use
python setup.py install. This copies the code into the site-packages directory. After that if you make any changes to the source code of the package, you need to run
python setup.py install each time.
The difference between that and
python setup.py develop is that in the later case Python does not copy the code to site-packages. It uses the code from that development folder directly whenever you import the package. This way if you make any changes to the package you don’t need to run
python setup.py install or
python setup.py develop.
After you are done with the development you can safely type
deactivate and this will turn off the virtualenv.
You can read more about virtualenv on Real Python. I hope someone out there in the same boat as one of my other readers finds this helpful.
Have a good day! ❤️