Rounding order affects total
Review this Python that rounds each line's tax to cents and totals an invoice that must reconcile against an external ledger using standard 'round half up'.
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1def round_cents(amount):
2 # amount is a float number of dollars, e.g. 2.675
3 return round(amount, 2)
4
5def invoice_tax(line_amounts, rate):
6 total = 0.0
7 for amt in line_amounts:
8 tax = amt * rate # e.g. 26.75 * 0.10 = 2.675
9 total += round_cents(tax)
10 return round_cents(total)
11
12# invoice_tax([26.75], 0.10) -> ledger expects 2.68
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