Developing in isolated environments

You may want to develop python programs and/or packages yourself. This is not the focus for this course.
However, below we present how one can use the isolated environment to spread your environment to colleagues or others who will use your software/scrips.

You may have a look on these pages

- Install dependencies by first recording them in requirements.txt or environment.yml and install using these files, then you have a trace. - Use isolated environments and avoid installing packages system-wide.

Packaging

Keypoints

It is worth it to organize your code for publishing, even if only you are using it.
PyPI is a place for Python packages
conda is similar but is not limited to Python

Creator/developer

First _create_ and _activate_ an environment (see above)
Install packages with pip
Create file from present virtual environment:

$ pip freeze > requirements.txt

That includes also the system site packages if you included them with --system-site-packages
Test that everything works by running use cases scripts within the environment
You can list packages specific for the virtualenv by pip list --local
So, creating a file from just the local environment:

$ pip freeze --local > requirements.txt

Note

requirements.txt (used by the virtual environment) is a simple text file which looks similar to this:

numpy
matplotlib
pandas
scipy

requirements.txt with versions that could look like this:

numpy==1.20.2
matplotlib==3.2.2
pandas==1.1.2
scipy==1.6.2

Deactivate

User

Create an environment based on dependencies given in an environment file
This can be done in new virtual environment or as a genera installtion locally (not activating any environment

pip install -r requirements.txt

Check

pip list