#!/usr/bin/env python3 """Independently verify this published synthetic ledger, using only stdlib. Run: python verify.py [directory-containing-the-CSV-and-JSON-files] The literal fixture oracle detects missing rows in THIS example. It cannot establish whether a player's real-world receipts are complete. No generator import and no assert statements (also works with python -O). """ import copy import csv import hashlib import io import json import re import sys from decimal import Decimal, localcontext, ROUND_HALF_UP from fractions import Fraction from pathlib import Path ENTRY_FIELDS = ['event_id', 'entry_id', 'currency', 'contribution_cents', 'fee_cents', 'paid_cents'] EVENT_FIELDS = ['event_id', 'currency', 'settled', 'expected_entries', 'prize_cents'] # Independently transcribed, fixed examples printed in the article. ENTRY_ORACLE = [ ['A', 'A1', 'USD', '10000', '1000', '11000'], ['A', 'A2', 'USD', '10000', '1000', '11000'], ['A', 'A3', 'USD', '10000', '1000', '11000'], ['B', 'B1', 'USD', '5000', '500', '5500'], ['C', 'C1', 'USD', '20000', '2000', '22000'], ['C', 'C2', 'USD', '20000', '2000', '22000'], ] EVENT_ORACLE = [ ['A', 'USD', 'true', '3', '25000'], ['B', 'USD', 'true', '1', '0'], ['C', 'USD', 'true', '2', '80000'], ] SCOPE = 'Completed self-funded cash-entry non-bounty events; no refunds, tickets, swaps, staking, rebuys, add-ons, expenses, tax or FX.' def require(condition, message): if not condition: raise ValueError(message) def csv_rows(text, fields): reader = csv.DictReader(io.StringIO(text)) require(reader.fieldnames == fields, 'Unexpected or duplicated CSV column names') rows = list(reader) require(rows and all(set(r) == set(fields) and all(v is not None for v in r.values()) for r in rows), 'Empty CSV, extra cell or missing cell') return rows def integer(value, field): require(isinstance(value, str) and re.fullmatch(r'0|[1-9][0-9]*', value) is not None, field + ' must be an explicit nonnegative integer') return int(value) def validate_rows(entries, events, use_oracle=True): event_ids = [r['event_id'] for r in events] entry_ids = [r['entry_id'] for r in entries] require(all(event_ids) and len(set(event_ids)) == len(event_ids), 'Duplicate/empty event ID: one settled prize record per event') require(all(entry_ids) and len(set(entry_ids)) == len(entry_ids), 'Duplicate/empty entry ID') for row in events: require(row['currency'] == 'USD', 'Event currency mismatch') require(row['settled'] == 'true', 'Unsettled event cannot be treated as a zero or final prize') require(integer(row['expected_entries'], 'expected_entries') > 0, 'Expected count must be positive') integer(row['prize_cents'], 'prize_cents') for row in entries: require(row['event_id'] in event_ids, 'Entry references a missing event') require(row['currency'] == 'USD', 'Entry currency mismatch') contribution = integer(row['contribution_cents'], 'contribution_cents') fee = integer(row['fee_cents'], 'fee_cents') paid = integer(row['paid_cents'], 'paid_cents') require(paid > 0, 'Every entry requires a known positive cost') require(contribution + fee == paid, 'Contribution plus fee must equal paid amount') for row in events: count = sum(r['event_id'] == row['event_id'] for r in entries) require(count == integer(row['expected_entries'], 'expected_entries'), 'Entry count does not reconcile') if use_oracle: require(sorted([r[f] for f in ENTRY_FIELDS] for r in entries) == ENTRY_ORACLE, 'Literal six-entry fixture mismatch; this is not proof of real-world completeness') require(sorted([r[f] for f in EVENT_FIELDS] for r in events) == EVENT_ORACLE, 'Literal three-event fixture mismatch') def ratio(value): with localcontext() as context: context.prec = 80 pct = (Decimal(value.numerator) * 100 / Decimal(value.denominator)).quantize(Decimal('0.01'), rounding=ROUND_HALF_UP) return {'numerator': value.numerator, 'denominator': value.denominator, 'percent_display': format(pct, '.2f')} def calculate(entries, events): out = [] for event in sorted(events, key=lambda r: r['event_id']): matching = [r for r in entries if r['event_id'] == event['event_id']] paid = sum(int(r['paid_cents']) for r in matching) prize = int(event['prize_cents']) out.append({'event_id': event['event_id'], 'entry_count': len(matching), 'paid_cents': paid, 'prize_cents': prize, 'net_cents': prize - paid, 'roi': ratio(Fraction(prize - paid, paid))}) paid = sum(r['paid_cents'] for r in out) prize = sum(r['prize_cents'] for r in out) net = prize - paid mean = sum((Fraction(r['net_cents'], r['paid_cents']) for r in out), Fraction()) / len(out) sensitivity = [] for count in (1, 2, 3): cost = count * 11000 sensitivity.append({'entry_count': count, 'paid_cents': cost, 'prize_cents': 25000, 'net_cents': 25000 - cost, 'roi': ratio(Fraction(25000 - cost, cost))}) require((paid, prize, net) == (82500, 105000, 22500), 'Literal total oracle failed') require(Fraction(net, paid) == Fraction(3, 11), 'Literal pooled ROI oracle failed') require(mean == Fraction(-14, 99), 'Literal event-mean oracle failed') return {'schema_version': 1, 'synthetic': True, 'currency': 'USD', 'scope': SCOPE, 'events': out, 'total': {'event_count': len(out), 'entry_count': len(entries), 'paid_cents': paid, 'prize_cents': prize, 'net_cents': net, 'roi': ratio(Fraction(net, paid))}, 'mean_event_roi': ratio(mean), 'unknown_A_entry_count_sensitivity': sensitivity} def json_pairs(pairs): result = {} for key, value in pairs: require(key not in result, 'Duplicate JSON key: ' + key) result[key] = value return result def same_json(actual, expected): # JSON string equality additionally distinguishes true/1 and 1.0/1. require(json.dumps(actual, sort_keys=True) == json.dumps(expected, sort_keys=True), 'Published result does not match independent exact calculation') def rejection_controls(entries, events, expected): controls = [] def reject(name, change, oracle=True): e, v = copy.deepcopy(entries), copy.deepcopy(events) change(e, v) try: validate_rows(e, v, oracle) except ValueError: controls.append(name) else: raise ValueError('Rejection control unexpectedly accepted: ' + name) reject('duplicate entry ID', lambda e, v: e[1].update(entry_id='A1')) reject('duplicate prize/event record', lambda e, v: v.append(dict(v[0]))) reject('missing event reference', lambda e, v: e[0].update(event_id='Z')) reject('entry currency mismatch', lambda e, v: e[0].update(currency='EUR')) reject('event currency mismatch', lambda e, v: v[0].update(currency='EUR')) reject('unsettled prize', lambda e, v: v[0].update(settled='false')) reject('unknown prize', lambda e, v: v[0].update(prize_cents='')) reject('negative prize', lambda e, v: v[0].update(prize_cents='-1')) reject('unknown paid cost', lambda e, v: e[0].update(paid_cents='')) reject('zero paid cost', lambda e, v: e[0].update(contribution_cents='0', fee_cents='0', paid_cents='0')) reject('negative fee', lambda e, v: e[0].update(fee_cents='-1')) reject('inexact split', lambda e, v: e[0].update(fee_cents='999')) reject('fractional cents', lambda e, v: e[0].update(paid_cents='11000.5')) reject('missing entry with original count', lambda e, v: e.pop(0)) def hide_entry(e, v): e.pop(0) v[0]['expected_entries'] = '2' # Demonstrate explicitly why counts alone cannot prove completeness. e, v = copy.deepcopy(entries), copy.deepcopy(events) hide_entry(e, v) validate_rows(e, v, use_oracle=False) reject('missing entry plus altered count rejected by fixed fixture oracle', hide_entry) altered = copy.deepcopy(expected) altered['total']['roi']['denominator'] = 22 try: same_json(altered, expected) except ValueError: controls.append('tampered published ratio') else: raise ValueError('Tampered result control unexpectedly accepted') return controls def verify_manifest(directory): path = directory / 'SHA256SUMS' if not path.exists(): return 'absent (optional during development)' count, seen = 0, set() for line in path.read_text(encoding='utf-8-sig').splitlines(): if not line.strip(): continue match = re.fullmatch(r'([0-9a-fA-F]{64})\s+\*?(.+)', line) require(match is not None, 'Malformed manifest line') digest, name = match.groups() require(name == Path(name).name and name not in ('.', '..') and '\\' not in name and '/' not in name, 'Manifest file must be a local basename') require(name not in seen, 'Duplicate manifest file') seen.add(name) target = directory / name require(target.is_file(), 'Manifest file missing: ' + name) require(hashlib.sha256(target.read_bytes()).hexdigest() == digest.lower(), 'Manifest digest mismatch: ' + name) count += 1 require({'entries.csv', 'events.csv', 'results.json', 'verify.py'} <= seen, 'Manifest omits a core fixture/verifier file') return str(count) + ' file hashes checked' def main(): require(len(sys.argv) <= 2, 'Usage: python verify.py [fixture-directory]') directory = Path(sys.argv[1]).resolve() if len(sys.argv) == 2 else Path(__file__).resolve().parent entries = csv_rows((directory / 'entries.csv').read_text(encoding='utf-8-sig'), ENTRY_FIELDS) events = csv_rows((directory / 'events.csv').read_text(encoding='utf-8-sig'), EVENT_FIELDS) validate_rows(entries, events) expected = calculate(entries, events) actual = json.loads((directory / 'results.json').read_text(encoding='utf-8-sig'), object_pairs_hook=json_pairs) same_json(actual, expected) controls = rejection_controls(entries, events, expected) print(json.dumps({'status': 'PASS', 'events': 3, 'entries': 6, 'exact_values': True, 'rejection_controls': controls, 'manifest': verify_manifest(directory), 'limitation': 'Validates a fixed synthetic fixture, not real-world receipt completeness.'}, indent=2)) if __name__ == '__main__': try: main() except (OSError, ValueError, csv.Error, KeyError) as error: print('FAIL: ' + str(error), file=sys.stderr) sys.exit(1)