add revolut

nlb-export/revolut.py

@@ -0,0 +1,95 @@
+import csv
+import re
+import sys
+from collections import Counter
+from datetime import datetime
+from decimal import Decimal
+from pathlib import Path
+# convert revolut account statement csv exports into the same shape as nlb.py / trade_republic.py
+STATEMENTS = "account-statement*.csv"
+IBAN = re.compile(r"\b[A-Z]{2}\d{2}[A-Z0-9]{11,30}\b")
+FIELDS = ["date", "desc", "account", "amount", "balance", "currency", "type"]
+
+
+def decimals(text):
+    return len(text.partition(".")[2])
+
+
+def scale(source):
+    """Revolut writes JPY without decimals and EUR with two, so follow the file."""
+    places = {}
+    for r in source:
+        seen = [decimals(r[c]) for c in ("Amount", "Fee", "Balance") if r[c]]
+        places[r["Currency"]] = max(seen + [places.get(r["Currency"], 0)])
+    return places
+
+
+def extract_transactions(path):
+    print(path)
+    with open(path, newline="") as f:
+        source = list(csv.DictReader(f))
+    source.sort(key=lambda r: r["Completed Date"])
+    places = scale(source)
+
+    rows = []
+    skipped = Counter()
+    for r in source:
+        if r["State"] != "COMPLETED" or not r["Balance"]:
+            skipped[r["State"]] += 1
+            continue
+        digits = places[r["Currency"]]
+        fee = Decimal(r["Fee"] or 0)
+        # the fee is deducted alongside the amount rather than booked separately
+        amount = Decimal(r["Amount"]) - fee
+        desc = r["Description"]
+        if fee:
+            desc += f" (fee {fee:.{digits}f})"
+        account = IBAN.search(desc)
+        rows.append({
+            "date": datetime.strptime(r["Completed Date"][:10], "%Y-%m-%d").strftime("%d.%m.%y"),
+            "desc": desc,
+            "account": account.group() if account else "",
+            "amount": f"{amount:+.{digits}f}",
+            "balance": f"{Decimal(r['Balance']):.{digits}f}",
+            "currency": r["Currency"],
+            "type": r["Type"],
+        })
+    for state, count in sorted(skipped.items()):
+        print(f"  skipped {count} {state or 'unfinished'} transactions")
+    return rows
+
+
+def check_balances(rows, path):
+    """Every balance must be the previous one plus the transaction amount."""
+    for currency in dict.fromkeys(row["currency"] for row in rows):
+        chain = [row for row in rows if row["currency"] == currency]
+        for prev, row in zip(chain, chain[1:]):
+            expected = Decimal(prev["balance"]) + Decimal(row["amount"])
+            if expected != Decimal(row["balance"]):
+                print(f"  warning: {path.name} {row['date']} {row['desc'][:40]!r} "
+                      f"balance {row['balance']} != {expected}")
+
+
+def main():
+    target = Path(sys.argv[1])
+    paths = sorted(target.glob(STATEMENTS)) if target.is_dir() else [target]
+    out_path = target.with_suffix(".csv")
+    if out_path in paths:
+        sys.exit(f"{out_path} would overwrite the statement it reads; pass the directory instead")
+
+    all_rows = []
+    for path in paths:
+        rows = extract_transactions(path)
+        check_balances(rows, path)
+        all_rows.extend(rows)
+
+    with open(out_path, "w", newline="") as f:
+        writer = csv.DictWriter(f, fieldnames=FIELDS)
+        writer.writeheader()
+        writer.writerows(all_rows)
+
+    print(f"Wrote {len(all_rows)} transactions to {out_path}")
+
+
+if __name__ == "__main__":
+    main()