highest-cost-scenario-identification

# Highest Cost Scenario Identification ## Dataset Overview The dabstep dataset models payment processing fees with these key files: - `fees.json`: 1000 fee rules, each specifying conditions and fee parameters - `merchant_category_codes.csv`: MCC descriptions (not exhaustive — fee rules may reference MCCs not in this file) - `manual.md`: Domain definitions including ACI codes (A–G) and fee formula **Fee formula**: `fee = fixed_amount + rate * transaction_amount / 10000` ## Two Question Types ### Type 1: Most Expensive MCC *"What is the most expensive MCC for a transaction of X euros, in general?"* Find which MCC(s) can incur the highest fee across all fee rules. ```python import json with open('fees.json') as f: fees = json.load(f) amount = 50 # transaction amount in euros mcc_max_fee = {} for rule in fees: mcc_list = rule['merchant_category_code'] if not mcc_list: # empty list means rule applies to all MCCs, skip for MCC ranking continue fee = rule['fixed_amount'] + rule['rate'] * amount / 10000 for mcc in mcc_list: mcc_max_fee[mcc] = max(mcc_max_fee.get(mcc, 0), fee) max_fee = max(mcc_max_fee.values()) result_mccs = sorted([mcc for mcc, f in mcc_max_fee.items() if f == max_fee]) # Output as comma-separated sorted list print(', '.join(str(m) for m in result_mccs)) ``` **Critical**: Do NOT filter MCCs against `merchant_category_codes.csv`. Some MCCs in fee rules (e.g., 3003, 7231) are absent from the description file but are valid and must be included in results. ### Type 2: Most Expensive ACI *"For a credit transaction of X euros on [CardScheme], what would be the most expensive ACI?"* Find which ACI letter leads to the highest possible fee for the specified card scheme and credit type. ```python import json with open('fees.json') as f: fees = json.load(f) card_scheme = 'GlobalCard' # exact match required is_credit = True amount = 1 # transaction amount in euros ALL_ACIS = ['A', 'B', 'C', 'D', 'E', 'F', 'G'] aci_max_fee = {} for rule in fees: # Filter by card scheme if rule['card_scheme'] != card_scheme: continue # Filter by credit status: null means applies to both credit and debit if rule['is_credit'] is not None and rule['is_credit'] != is_credit: continue fee = rule['fixed_amount'] + rule['rate'] * amount / 10000 # Empty aci list means rule applies to ALL ACI values acis = rule['aci'] if rule['aci'] else ALL_ACIS for aci in acis: aci_max_fee[aci] = max(aci_max_fee.get(aci, 0), fee) max_fee = max(aci_max_fee.values()) best_acis = sorted([a for a, f in aci_max_fee.items() if f == max_fee]) result = best_acis[0] # alphabetically first when tied print(result) # Output: single letter like 'C' ``` ## Key Rules and Pitfalls ### Null/Empty field semantics (from manual.md) | Field | Null/Empty means | |-------|-----------------| | `is_credit: null` | Applies to both credit and debit | | `aci: []` | Applies to all ACI values (A–G) | | `merchant_category_code: []` | Applies to all MCCs (skip for MCC ranking) | | `account_type: []` | Applies to all account types | | Other null fields | Apply to all values of that field | ### Common errors to avoid 1. **Filtering MCCs by merchant_category_codes.csv** — wrong. MCC 3003 and 7231 exist in fee rules but not in the CSV. Always use the MCCs from `fees.json` directly. 2. **Outputting fee amount instead of ACI letter** — for ACI questions the answer is a letter (e.g., `C`), not the fee value (e.g., `0.23`). 3. **Ignoring null is_credit rules for ACI questions** — rules with `is_credit: null` apply to credit transactions and must be included. 4. **Forgetting empty aci list** — an empty `aci` list in a rule means it covers ALL ACIs; don't skip these rules. ### "In general" interpretation "Most expensive in general" means the worst-case maximum fee across all possible rule configurations. For each MCC or ACI, find the highest fee achievable under any applicable fee rule — you do not need to match all rule conditions, just find the global maximum. ## Output Format - **MCC questions**: Comma-separated sorted list of MCC integers, e.g., `3000, 3001, 3002` - **ACI questions**: Single letter in a list, e.g., `['C']` or `["C"]` — do NOT output the fee amount ## ACI Reference (from manual.md) | ACI | Description | |-----|-------------| | A | Card Present - Non-authenticated | | B | Card Present - Authenticated | | C | Tokenized card with mobile device | | D | Card Not Present - Card On File | | E | Card Not Present - Recurring Bill Payment | | F | Card Not Present - 3-D Secure | | G | Card Not Present - Non-3-D Secure | ## Card Schemes in Dataset GlobalCard, NexPay, SwiftCharge, TransactPlus