Purchasing power parity calculator

Adjust a given amount for a given country after the purchasing power parity (PPP) indicator using the Netherlands as reference. Corresponding ratios are computed from the amounts provided by the Google Summer of Code Stipend Amounts Table (CC-BY-4.0), and rounded to an integer.

Usage

Specify amount and country in order to get the adjusted amount for the given country:

$ python ppp.py 500 Brazil
278

Set a different reference country with --reference:

$ python ppp.py 500 Brazil --reference Australia
227

The year can be specified when needed, defaulting to the current year:

$ python ppp.py 500 Brazil 2022
333

Add exceptions for countries listed in a file:

$ python ppp.py 500 Luxembourg --ignore european-union.txt
500

Purchasing power parity data

The year has to correspond to a <year>.csv table whose contents can be fetched by using the helper script update.py. This script takes a URL to the GSoC contributor stipends page, or a snapshot of it from previous years (see e.g., the Wayback Machine of the Internet Archive to get a snapshot). Its contents can then be stored in the working directory as follows:

$ python update.py https://web.archive.org/web/20220809160247/https://developers.google.com/open-source/gsoc/help/student-stipends >> 2022.csv

Update the list of member states of the European Union:

$ python update_eu.py > european-union.txt

Nix

A Nix derivation, shell.nix, has been added to ensure reproducibility across the board.

• Install Nix

• Clone this repository

  git clone https://github.com/wamirez/ppp-calc

• Enter the Nix shell

  $ cd ppp-calc
  $ nix-shell

nix-shell picks up shell.nix automatically installing required packages and creating a custom Python environment.