AP DEJA-VU

That strange feeling we sometimes get that we've lived through something before.

ap-deja-vu is a small web service that will replay JSON from an AP election test. ap-deja-vu does not require a database for persistence and does not write to the filesystem.

Important Notes

• ap-deja-vu requires that you have already recorded an AP election test to JSON files. Elex-loader is highly recommended for this process. Contact your AP support representative to get an up-to-date schedule for election tests.

• This software assumes you have two AP API keys; one for national data, and one for local data.

User interface

Getting Started

Install requirements

ap-deja-vu requires a running redis instance on localhost. Install with homebrew (development on a Mac) or via apt-get (production use on an Ubuntu-based server).

Mac

Requires Homebrew.

brew install redis
brew services start redis

Ubuntu Linux

Sudo apt-get install redis-server

Install this app

mkvirtualenv ap-deja-vu && git clone git@github.com:newsdev/ap-deja-vu.git && cd ap-deja-vu
pip install -r requirements.txt
add2virtualenv ap_deja_vu

Run The Server

python -m ap_deja_vu.app

How It Works

Environment Variables

Export an AP_DEJAVU_DATA_DIRECTORY environment variable.

export AP_DEJAVU_DATA_DIRECTORY=/tmp/ap-elex-data/

AP Elections Files

Your data directory should contain a series of folders corresponding to AP election dates. Within each of those folders, ap-deja-vu expects a series of files, named as UNIX timestamps. Really, any incrementing number or letter combination will work as long as the default sort produces the correct order. Each of these files should contain the output of the AP election API v2. Use this layout as a guide:

/tmp/
    /ap-elex-data/
        /2016-02-01/
                /local/
                    001.json
                    002.json
                    003.json
                /national/
                    001.json
                    002.json
                    003.json
        /2016-02-09/
                /local/
                    001.json
                    002.json
                    003.json
                /national/
                    001.json
                    002.json
                    003.json

We recommend The New York Times's Elex-loader for capturing and parsing AP election data. Pay particular attention to the get_national_results and get_local_results functions in this script.

Playback

The route /<election_date> will replay the election files found in the folder /<DATA_DIR>/<election_date>/. The files should be named such that the first file will be sorted first in a list by glob.glob(), e.g., a higher letter (a) or lower number (0). Incrementing UNIX timestamps (such as those captured by Elex) would be ideal.

This route takes two optional control parameters. Once these have been passed to set up an election test, the raw URL will obey the instructions below until the last file in the hopper has been reached.

• position will return the file at this position in the hopper. So, for example, position=0 would set the pointer to the the first file in the hopper and return it.

• playback will increment the position by itself until it is reset. So, for example, playback=5 would skip to every fifth file in the hopper.

When the last file in the hopper has been reached, it will be returned until the Flask app is restarted OR a new pair of control parameters are passed.

Example: Let's say you would like to test an election at 10x speed. You have 109 files in your /<DATA_DIR>/<election_date>/ folder named 001.json through 109.json

• Request 1: /<election_date>?position=0&playback=10&national=true > 001.json
• Request 2: /<election_date>?national=true > 011.json
• Request 3: /<election_date>?national=true > 021.json
• Request 4: /<election_date>?national=true > 031.json
• Request 5: /<election_date>?national=true > 041.json
• Request 6: /<election_date>?national=true > 051.json
• Request 7: /<election_date>?national=true > 061.json
• Request 8: /<election_date>?national=true > 071.json
• Request 9: /<election_date>?national=true > 081.json
• Request 10: /<election_date>?national=true > 091.json
• Request 11: /<election_date>?national=true > 101.json
• Request 12: /<election_date>?national=true > 109.json
• Request 13 - ???: /<election_date>?national=true > 109.json

Requesting /<election_date>?position=0&playback=1&national=true will reset to the default position and playback speeds, respectively.

Status

The route /<election_date>/status will return the status of a given election date test, including the current position in the hopper, the playback speed, and the path of the file that will be served at the current position.

{
    position: 22,
    playback: 1,
    file: "/tmp/ap-elex-data/2016-02-09/ap_elections_loader_recording-1449676507.json"
}