enrich-with-currency

Enrich With Currency (ISO 4217)

Map ISO 3166 country codes to ISO 4217 currency codes.

When to invoke

• Dataset has ISO 3166 codes (alpha-2, alpha-3, or numeric) and the user wants currency information added.
• If only country names are present, invoke add-iso3166 first.

Procedure

1. Locate the dataset and confirm format.
2. Identify the ISO 3166 column — auto-detect iso3166_alpha2/alpha3/numeric or country_code. Ask if ambiguous.
3. Load the country→currency mapping:
   • Primary source: pycountry currencies via country subdivisions is incomplete; use the ISO 4217 country-currency table. Recommended library: babel.numbers.get_territory_currencies(territory, date) which returns currently-used currencies for a country code. Install with pip install babel.
   • Fallback: embed a static country_alpha2 → currency_alpha3 map (e.g. from the iso4217 package or a maintained CSV).
4. Add columns (ask which subset, default all):
   • currency_code (ISO 4217 alpha-3, e.g. USD, EUR)
   • currency_numeric (ISO 4217 numeric)
   • currency_name (e.g. "United States dollar")
   • currency_symbol (e.g. $, €)
5. Handle multi-currency territories — some countries use multiple currencies (e.g. Zimbabwe, Panama). Default to the most commonly used; flag the row and list alternatives in a notes column if the user wants.
6. Handle currency unions — Eurozone members all map to EUR; CFA franc zones map to XOF/XAF. This should fall out of the mapping naturally.
7. Report unresolved rows and write output with _currency suffix.
8. Update the data dictionary.

Dependencies

pip install pandas pycountry babel

Edge cases

• Dependent territories (e.g. Puerto Rico → USD, Greenland → DKK) — verify the mapping source covers these.
• Countries with dual currencies — document the chosen default in the data dictionary.
• Historical currencies — out of scope; this skill maps to currently-active currencies only.