Unicode RBNF
A pure Python implementation of rule based number formatting (RBNF) using the Unicode Common Locale Data Repository (CLDR).
This lets you spell out numbers for a large number of locales:
from unicode_rbnf import RbnfEngine
engine = RbnfEngine.for_language("en")
assert engine.format_number(1234).text == "one thousand two hundred thirty-four"
Different formatting purposes are supported as well, depending on the locale:
from unicode_rbnf import RbnfEngine, FormatPurpose
engine = RbnfEngine.for_language("en")
assert engine.format_number(1999, FormatPurpose.CARDINAL).text == "one thousand nine hundred ninety-nine"
assert engine.format_number(1999, FormatPurpose.YEAR).text == "nineteen ninety-nine"
assert engine.format_number(11, FormatPurpose.ORDINAL).text == "eleventh"
For locales with multiple genders, cases, etc., the different texts are accessible in the result of format_number
:
from unicode_rbnf import RbnfEngine
engine = RbnfEngine.for_language("de")
print(engine.format_number(1))
Result:
FormatResult(
text='eins',
text_by_ruleset={
'spellout-numbering': 'eins',
'spellout-cardinal-neuter': 'ein',
'spellout-cardinal-masculine': 'ein',
'spellout-cardinal-feminine': 'eine',
'spellout-cardinal-n': 'einen',
'spellout-cardinal-r': 'einer',
'spellout-cardinal-s': 'eines',
'spellout-cardinal-m': 'einem'
}
)
The text
property of the result holds the text of the ruleset with the shortest name (least specific).
Supported locales
See: https://github.com/unicode-org/cldr/tree/release-44/common/rbnf
Engine implementation
Not all features of the RBNF engine are implemented. The following features are available:
- Literal text (
hundred
) - Quotient substitution (
<<
or ←←
) - Reminder substitution (
>>
or →→
) - Optional substitution (
[...]
) - Rule substituton (
←%ruleset_name←
) - Rule replacement (
=%ruleset_name=
) - Special rules:
- Negative numbers (
-x
) - Improper fractions (
x.x
) - Not a number (
NaN
) - Infinity (
Inf
)
Some features that will need to be added eventually:
- Proper fraction rules (
0.x
) - Preceding reminder substitution (
>>>
or →→→
) - Number format strings (
==
) - Decimal format patterns (
#,##0.00
) - Plural replacements (
$(ordinal,one{st}...)
)