Introduction

This repo contains two main things:

1. the exploratory data analysis for Districtr to see if it was possible to calculate contiguity and cut edges;
2. an implementation of a server that calculates contiguity and cut edges in real time on the Districtr app.

Exploratory data analysis for Districtr

This is what I did for the week 21--27 June: find a way to convert Districtr JSON assingments to GerryChain partitions.

Server that calculates contiguity and cut edges in real time

This is a FLASK server that listens for POST requests from the Districtr app. The POST request will contain a JSON object which is an assignment of geographic units to districts, and the server will return the number of cut edges and whether or not the plan is contiguous.

I am working on some additional features

How to set up this server on PythonAnywhere

On the command line, first clone this repository:

git clone https://github.com/lieuzhenghong/districtr-eda

Then install Git LFS. It's a bit of a faff to get Git LFS setup on PythonAnywhere but this guide is very helpful:

wget the latest release from https://github.com/git-lfs/git-lfs/releases.

Then tar -xvf the latest release, and edit the install.sh file: find the line that says prefix= and change it to prefix="~/.local/bin.

Then ./install.sh.

Then, go to the PythonAnywhere dashboard. In the "Web" tab, do the following:

1. Under the "Code" heading, point "Source code:" to /home/mggg/districtr-eda.

2. On the WSGI configuration file mggg_pythonanywhere_com_wsgi.py, set the following under the Flask section:

# +++++++++++ FLASK +++++++++++
# Flask works like any other WSGI-compatible framework, we just need
# to import the application.  Often Flask apps are called "app" so we
# may need to rename it during the import:
#
import sys
#
## The "/home/lieu" below specifies your home
## directory -- the rest should be the directory you uploaded your Flask
## code to underneath the home directory.  So if you just ran
## "git clone git@github.com/myusername/myproject.git"
## ...or uploaded files to the directory "myproject", then you should
## specify "/home/lieu/myproject"
path = '/home/lieu/districtr-eda'
if path not in sys.path:
    sys.path.append(path)

from server import app as application  # noqa

Finally,

cd districtr-eda
pip3 install -r --user
export FLASK_APP=server.py
flask run

and you should observe

* Serving Flask app "server.py"
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)