iso_4217: Yet another currency data package for Python

This package contains ISO 4217 active and historical currency data. Written and tested for Python 3.6 and above. Supports pint for operations with currency units.

>>> from iso_4217 import Currency
>>> Currency.USD
<Currency.USD: 'US Dollar'>
>>> Currency.USD.value
'US Dollar'
>>> Currency('US Dollar')
<Currency.USD: 'US Dollar'>
>>> Currency.JPY.entities
frozenset({'JAPAN'})
>>> Currency.ZWR
<Currency.ZWR: 'Zimbabwe Dollar (2009)'>
>>> Currency.ZWR.entities
frozenset()
>>> Currency.ZWR.withdrew_entities
(Historic(entity='ZIMBABWE', name='Zimbabwe Dollar'...2009, month=6), begin=None)),)

Pint units and subunits are available with convenient unit and subunit properties on Currency. Accessing these properties requires pint package installed and automatically defines currency units in application default registry.

>>> Currency.USD.unit * 5 + Currency.USD.subunit * 5
<Quantity(5.05, 'USD')>

Currency units can be defined in any UnitRegistry manually

>>> import pint
>>> from decimal import Decimal
>>> from iso_4217 import define_currency_units
>>> reg = define_currency_units(pint.UnitRegistry(non_int_type=Decimal))
>>> 5 * reg.USD
<Quantity(5, 'USD')>

But units from separate registries should not be mixed

>>> Currency.USD.unit == reg.USD
Traceback (most recent call last):
...
ValueError: Cannot operate with Unit and Unit of different registries.

If you want to replace registry used by Currency just replace the application registry:

>>> pint.set_application_registry(reg)
>>> Currency.USD.unit == reg.USD
True

Subunits are defined with s suffix:

>>> 5 * reg.USDs
<Quantity(5, 'USDs')>
>>> (5 * reg.USDs).to("USD")
<Quantity(0.05, 'USD')>
>>> (5 * reg.BHDs).to_base_units()
<Quantity(0.005, 'BHD')>

Each currency is defined within it’s own dimension:

>>> (5 * reg.USD).to('EUR')
Traceback (most recent call last):
...
pint.errors.DimensionalityError: Cannot convert from 'USD' ([currency_USD]) to 'EUR' ([currency_EUR])

But automatic currency conversion can be made via pint Contexts

>>> context = pint.Context()
>>> eur_to_usd = lambda r, eur: eur * r("1.2 USD/EUR")
>>> context.add_transformation("[currency_EUR]", "[currency_USD]", eur_to_usd)
>>> (Currency.EUR.unit * 5).to('USD', context)
<Quantity(6.0, 'USD')>

Inspired by iso4217 package by Hong Minhee.