v0.3.0

⚠️ Breaking release

This release renames the year-month value type and everything named after it, and ships the first Python bindings on PyPI.

Python bindings — new

pip install hmrc-rates (Python ≥ 3.10). abi3 wheels for Linux (glibc + musl, x86_64 + aarch64), macOS (universal2) and Windows (x64); the sdist builds anywhere with a Rust toolchain.

from decimal import Decimal
from hmrc_rates import YearMonth, Rates, YearEnd

rates = Rates()
rate = rates.monthly_rate("USD", YearMonth(2025, 8))   # also accepts datetime.date or "2025-08"
gbp = rate.to_gbp(Decimal("2500"))                     # exact decimal.Decimal — you choose the rounding

Breaking changes

Rust crate

• Month → YearMonth, and ParseMonthError → ParseYearMonthError.
• month arguments → year_month on Rates::monthly_rate, monthly_rate_or_earlier, monthly.
• YearEnd::from_month → from_year_month; YearEnd::end_month → end_year_month.
• Period::Month variant → Period::YearMonth.
• Serde wire format changed: a Period now serializes as {"year_month": "2025-08"} (previously {"month": …}). Data serialized by earlier versions will not deserialize.
• The dependency pin is now hmrc-rates = "0.3".

Python

• Class Month → YearMonth; type alias MonthLike → YearMonthLike.
• Keyword argument month= → year_month= on the lookup methods.
• YearEnd.from_month → from_year_month; YearEnd.end_month → end_year_month.
• Period.kind now returns "year_month" (was "month"); the Period.month property is now Period.year_month.

Unchanged

YearMonth.month/.year (the numeric 1–12 month and the year), RateType/MONTHLY, the monthly*() lookups, the exception hierarchy, and the bundled data coverage.