ABERRANT_PLURAL_MAP = {
'appendix': 'appendices',
'barracks': 'barracks',
'cactus': 'cacti',
'child': 'children',
'criterion': 'criteria',
'deer': 'deer',
'echo': 'echoes',
'elf': 'elves',
'embargo': 'embargoes',
'focus': 'foci',
'fungus': 'fungi',
'goose': 'geese',
'hero': 'heroes',
'hoof': 'hooves',
'index': 'indices',
'knife': 'knives',
'leaf': 'leaves',
'life': 'lives',
'man': 'men',
'mouse': 'mice',
'nucleus': 'nuclei',
'person': 'people',
'phenomenon': 'phenomena',
'potato': 'potatoes',
'self': 'selves',
'syllabus': 'syllabi',
'tomato': 'tomatoes',
'torpedo': 'torpedoes',
'veto': 'vetoes',
'woman': 'women',
}
VOWELS = set('aeiou')
def pluralize(singular):
"""Return plural form of given lowercase singular word (English only). Based on
ActiveState recipe http://code.activestate.com/recipes/413172/
>>> pluralize('')
''
>>> pluralize('goose')
'geese'
>>> pluralize('dolly')
'dollies'
>>> pluralize('genius')
'genii'
>>> pluralize('jones')
'joneses'
>>> pluralize('pass')
'passes'
>>> pluralize('zero')
'zeros'
>>> pluralize('casino')
'casinos'
>>> pluralize('hero')
'heroes'
>>> pluralize('church')
'churches'
>>> pluralize('x')
'xs'
>>> pluralize('car')
'cars'
"""
if not singular:
return ''
plural = ABERRANT_PLURAL_MAP.get(singular)
if plural:
return plural
root = singular
try:
if singular[-1] == 'y' and singular[-2] not in VOWELS:
root = singular[:-1]
suffix = 'ies'
elif singular[-1] == 's':
if singular[-2] in VOWELS:
if singular[-3:] == 'ius':
root = singular[:-2]
suffix = 'i'
else:
root = singular[:-1]
suffix = 'ses'
else:
suffix = 'es'
elif singular[-2:] in ('ch', 'sh'):
suffix = 'es'
else:
suffix = 's'
except IndexError:
suffix = 's'
plural = root + suffix
return plural
if __name__ == '__main__':
import doctest
doctest.testmod()
