Long method (ARCH2180)

Key python.quality.long-method · Severity info · Category quality

Overly long functions carry multiple responsibilities and become hard to read and test. Split the logic into small, named helper functions.

Incorrect

def process_order(order):
    total = 0
    for item in order.items:
        total += item.price * item.qty
    discount = total * 0.1 if total > 100 else 0
    total -= discount
    tax = total * 0.18
    total += tax
    send_email(order.user, total)
    log.info("processed")
    return total

Correct

def process_order(order):
    total = _subtotal(order) - _discount(order)
    total += total * 0.18
    _notify(order.user, total)
    return total

def _subtotal(order):
    return sum(i.price * i.qty for i in order.items)

Fix

Break the function into small single-responsibility helpers along its logical steps.