Redistricting Analytics in Python

This repository (rdapy) re-implements the main analytics used in Dave's Redistricting (DRA). Unlike the analytics used in the app (dra-analytics) which are implememented in TypeScript, these are implemented as a Python package to make them easier to use outside of DRA. There is also a command-line interface for high-volume scoring.

These are described in detail at the website for this repository.

To use it in your Python, install the package. To use the high-volume scoring scripts, set up the command-line interface.

To install the package:

pip install rdapy

The latest version of the package is 3.0.3.

Then in your code, either import rdapy or from rdapy import ....

Before installing the command-line interface (CLI), make sure you have the prerequisites installed.

The high-volume scoring scripts require Python 3.12 or later. If that is not the default on your computer, you can use pyenv to manage multiple Python versions. These instructions assume you're using pyenv.

Install pyenv from Homebrew:

brew install pyenv

Completing that setup will involve adding a few lines to your shell profile file (like .bash_profile).

You can install Python 3.12 from Homebrew:

brew install python@3.12

With the prequisites installed, clone the GitHub repository:

git clone https://github.com/dra2020/rdapy
cd rdapy

Then create a virtual environment that uses Python 3.12, and then reset Python outside the virtual environment to the normal setting:

pyenv shell 3.12
python3 -m venv /path/to/venvs/rdapy
source /path/to/venvs/rdapy/bin/activate
deactivate
pyenv shell --unset

Then activate the virtual environment again, and install the required dependencies:

source /path/to/venvs/rdapy/bin/activate
pip install -r requirements.txt
pip install --upgrade pip
export PYTHONPATH="${PYTHONPATH}:$(pwd)"

Finally, test that the automated tests run:

pytest

Then test that the command-line interface works. First, unzip the sample GeoJSON and graph package:

scripts/UNZIP-GEOJSON.sh \
--input testdata/examples/Geojson_NC.zip \
--output /dir/for/unzipped/files

Replace /dir/for/unzipped/files with the directory where you want the unzipped files to go. The directory does not have to exist. The root directory can be /tmp. The output directory will contain four files:

• A license file
• A README file
• A GeoJSON like this NC_2020_VD_tabblock.vtd.datasets.geojson, and
• An adjacency graphy like this NC_2020_graph.json

Then score some sample plans:

scripts/score/SCORE.sh \
--state NC \
--plan-type congress \
--geojson /dir/for/unzipped/files/NC_2020_VD_tabblock.vtd.datasets.geojson \
--graph /dir/for/unzipped/files/NC_2020_graph.json \
--precomputed testdata/examples/NC_congress_precomputed.json \
--plans testdata/plans/NC_congress_plans.tagged.jsonl \
--scores /path/to/TEST_scores.csv \
--by-district /path/to/TEST_by-district.jsonl

The --scores and by-district paths are where you want the scores CSV and by-district JSONL aggregates files to be saved, respectively.

There is a sample launch.json for VS Code debugging in the docs directory.

Run automated tests with:

pytest

Email questions to feedback.