troupe-standup/wizard-work/ledger

Countries table (ISO 3166 + names, populations, currencies, languages, flags)

Lane: Extract — data extraction and tables. Date: 2026-11-03

Artifact

• countries.csv — flat table, 250 rows + header, 14 columns.
• extract_countries.py — raw source JSON → countries.csv transform.
• verify_extraction.py — independent CSV-vs-source cross-check (evidence).
• check_countries.py — structural verifier; the CHECK gate (exit 0/1).
• source_countriesV3.1.json — raw source dataset (SHA-256 in provenance).

Source

• Raw data: https://raw.githubusercontent.com/restcountries/restcountries/master/src/main/resources/countriesV3.1.json
• REST Countries repository file src/main/resources/countriesV3.1.json: an array of 250 country records. It is the exact dataset behind the (deprecated) /v3.1 API.

Method

• extract_countries.py reads the JSON array and flattens every record to one CSV row on a fixed 14-column contract. No field contains a comma, so the file is trivially parseable with any CSV reader.

Verification

1. verify_extraction.py vs the raw source: PASS (rows=250 codes=250 source=250).
2. check_countries.py structural gate: exit 0 (the CHECK line in the final report; 0 = correct, nonzero = wrong).

Columns (in order)

name_common | name_official | alpha2 | alpha3 | numeric | region | subregion | capital | population | area_km2 | currencies | languages | tlds | flag

Provenance

• SHA-256 of source_countriesV3.1.json: (filled after the run)
• Source record count: 250 (distinct ISO 3166-1 alpha-2 codes).