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# -*- coding: utf-8 -*-
A port of Ruby on Rails' inflector to Python.
:copyright: (c) 2012-2020 by Janne Vanhala
:license: MIT, see LICENSE for more details.
import re
import unicodedata
__version__ = '0.4.0'
(r"(?i)(quiz)$", r'\1zes'),
(r"(?i)^(oxen)$", r'\1'),
(r"(?i)^(ox)$", r'\1en'),
(r"(?i)(m|l)ice$", r'\1ice'),
(r"(?i)(m|l)ouse$", r'\1ice'),
(r"(?i)(passer)s?by$", r'\1sby'),
(r"(?i)(matr|vert|ind)(?:ix|ex)$", r'\1ices'),
(r"(?i)(x|ch|ss|sh)$", r'\1es'),
(r"(?i)([^aeiouy]|qu)y$", r'\1ies'),
(r"(?i)(hive)$", r'\1s'),
(r"(?i)([lr])f$", r'\1ves'),
(r"(?i)([^f])fe$", r'\1ves'),
(r"(?i)sis$", 'ses'),
(r"(?i)([ti])a$", r'\1a'),
(r"(?i)([ti])um$", r'\1a'),
(r"(?i)(buffal|potat|tomat)o$", r'\1oes'),
(r"(?i)(bu)s$", r'\1ses'),
(r"(?i)(alias|status)$", r'\1es'),
(r"(?i)(octop|vir)i$", r'\1i'),
(r"(?i)(octop|vir)us$", r'\1i'),
(r"(?i)^(ax|test)is$", r'\1es'),
(r"(?i)s$", 's'),
(r"$", 's'),
(r"(?i)(database)s$", r'\1'),
(r"(?i)(quiz)zes$", r'\1'),
(r"(?i)(matr)ices$", r'\1ix'),
(r"(?i)(vert|ind)ices$", r'\1ex'),
(r"(?i)(passer)sby$", r'\1by'),
(r"(?i)^(ox)en", r'\1'),
(r"(?i)(alias|status)(es)?$", r'\1'),
(r"(?i)(octop|vir)(us|i)$", r'\1us'),
(r"(?i)^(a)x[ie]s$", r'\1xis'),
(r"(?i)(cris|test)(is|es)$", r'\1is'),
(r"(?i)(shoe)s$", r'\1'),
(r"(?i)(o)es$", r'\1'),
(r"(?i)(bus)(es)?$", r'\1'),
(r"(?i)(m|l)ice$", r'\1ouse'),
(r"(?i)(x|ch|ss|sh)es$", r'\1'),
(r"(?i)(m)ovies$", r'\1ovie'),
(r"(?i)(s)eries$", r'\1eries'),
(r"(?i)([^aeiouy]|qu)ies$", r'\1y'),
(r"(?i)([lr])ves$", r'\1f'),
(r"(?i)(tive)s$", r'\1'),
(r"(?i)(hive)s$", r'\1'),
(r"(?i)([^f])ves$", r'\1fe'),
(r"(?i)(t)he(sis|ses)$", r"\1hesis"),
(r"(?i)(s)ynop(sis|ses)$", r"\1ynopsis"),
(r"(?i)(p)rogno(sis|ses)$", r"\1rognosis"),
(r"(?i)(p)arenthe(sis|ses)$", r"\1arenthesis"),
(r"(?i)(d)iagno(sis|ses)$", r"\1iagnosis"),
(r"(?i)(b)a(sis|ses)$", r"\1asis"),
(r"(?i)(a)naly(sis|ses)$", r"\1nalysis"),
(r"(?i)([ti])a$", r'\1um'),
(r"(?i)(n)ews$", r'\1ews'),
(r"(?i)(ss)$", r'\1'),
(r"(?i)s$", ''),
def _irregular(singular, plural):
A convenience function to add appropriate rules to plurals and singular
for irregular words.
:param singular: irregular word in singular form
:param plural: irregular word in plural form
def caseinsensitive(string):
return ''.join('[' + char + char.upper() + ']' for char in string)
if singular[0].upper() == plural[0].upper():
PLURALS.insert(0, (
r"(?i)({}){}$".format(singular[0], singular[1:]),
r'\1' + plural[1:]
PLURALS.insert(0, (
r"(?i)({}){}$".format(plural[0], plural[1:]),
r'\1' + plural[1:]
SINGULARS.insert(0, (
r"(?i)({}){}$".format(plural[0], plural[1:]),
r'\1' + singular[1:]
PLURALS.insert(0, (
plural[0].upper() + plural[1:]
PLURALS.insert(0, (
plural[0].lower() + plural[1:]
PLURALS.insert(0, (
r"{}{}$".format(plural[0].upper(), caseinsensitive(plural[1:])),
plural[0].upper() + plural[1:]
PLURALS.insert(0, (
r"{}{}$".format(plural[0].lower(), caseinsensitive(plural[1:])),
plural[0].lower() + plural[1:]
SINGULARS.insert(0, (
r"{}{}$".format(plural[0].upper(), caseinsensitive(plural[1:])),
singular[0].upper() + singular[1:]
SINGULARS.insert(0, (
r"{}{}$".format(plural[0].lower(), caseinsensitive(plural[1:])),
singular[0].lower() + singular[1:]
def camelize(string, uppercase_first_letter=True):
Convert strings to CamelCase.
>>> camelize("device_type")
>>> camelize("device_type", False)
:func:`camelize` can be thought of as a inverse of :func:`underscore`,
although there are some cases where that does not hold::
>>> camelize(underscore("IOError"))
:param uppercase_first_letter: if set to `True` :func:`camelize` converts
strings to UpperCamelCase. If set to `False` :func:`camelize` produces
lowerCamelCase. Defaults to `True`.
if uppercase_first_letter:
return re.sub(r"(?:^|_)(.)", lambda m:, string)
return string[0].lower() + camelize(string)[1:]
def dasherize(word):
"""Replace underscores with dashes in the string.
>>> dasherize("puni_puni")
return word.replace('_', '-')
def humanize(word):
Capitalize the first word and turn underscores into spaces and strip a
trailing ``"_id"``, if any. Like :func:`titleize`, this is meant for
creating pretty output.
>>> humanize("employee_salary")
'Employee salary'
>>> humanize("author_id")
word = re.sub(r"_id$", "", word)
word = word.replace('_', ' ')
word = re.sub(r"(?i)([a-z\d]*)", lambda m:, word)
word = re.sub(r"^\w", lambda m:, word)
return word
def ordinal(number):
Return the suffix that should be added to a number to denote the position
in an ordered sequence such as 1st, 2nd, 3rd, 4th.
>>> ordinal(1)
>>> ordinal(2)
>>> ordinal(1002)
>>> ordinal(1003)
>>> ordinal(-11)
>>> ordinal(-1021)
number = abs(int(number))
if number % 100 in (11, 12, 13):
return "th"
return {
1: "st",
2: "nd",
3: "rd",
}.get(number % 10, "th")
def ordinalize(number):
Turn a number into an ordinal string used to denote the position in an
ordered sequence such as 1st, 2nd, 3rd, 4th.
>>> ordinalize(1)
>>> ordinalize(2)
>>> ordinalize(1002)
>>> ordinalize(1003)
>>> ordinalize(-11)
>>> ordinalize(-1021)
return "{}{}".format(number, ordinal(number))
def parameterize(string, separator='-'):
Replace special characters in a string so that it may be used as part of a
'pretty' URL.
>>> parameterize(u"Donald E. Knuth")
string = transliterate(string)
# Turn unwanted chars into the separator
string = re.sub(r"(?i)[^a-z0-9\-_]+", separator, string)
if separator:
re_sep = re.escape(separator)
# No more than one of the separator in a row.
string = re.sub(r'%s{2,}' % re_sep, separator, string)
# Remove leading/trailing separator.
string = re.sub(r"(?i)^{sep}|{sep}$".format(sep=re_sep), '', string)
return string.lower()
def pluralize(word):
Return the plural form of a word.
>>> pluralize("posts")
>>> pluralize("octopus")
>>> pluralize("sheep")
>>> pluralize("CamelOctopus")
if not word or word.lower() in UNCOUNTABLES:
return word
for rule, replacement in PLURALS:
if, word):
return re.sub(rule, replacement, word)
return word
def singularize(word):
Return the singular form of a word, the reverse of :func:`pluralize`.
>>> singularize("posts")
>>> singularize("octopi")
>>> singularize("sheep")
>>> singularize("word")
>>> singularize("CamelOctopi")
for inflection in UNCOUNTABLES:
if'(?i)\b(%s)\Z' % inflection, word):
return word
for rule, replacement in SINGULARS:
if, word):
return re.sub(rule, replacement, word)
return word
def tableize(word):
Create the name of a table like Rails does for models to table names. This
method uses the :func:`pluralize` method on the last word in the string.
>>> tableize('RawScaledScorer')
>>> tableize('egg_and_ham')
>>> tableize('fancyCategory')
return pluralize(underscore(word))
def titleize(word):
Capitalize all the words and replace some characters in the string to
create a nicer looking title. :func:`titleize` is meant for creating pretty
>>> titleize("man from the boondocks")
'Man From The Boondocks'
>>> titleize("x-men: the last stand")
'X Men: The Last Stand'
>>> titleize("TheManWithoutAPast")
'The Man Without A Past'
>>> titleize("raiders_of_the_lost_ark")
'Raiders Of The Lost Ark'
return re.sub(
lambda match:,
def transliterate(string):
Replace non-ASCII characters with an ASCII approximation. If no
approximation exists, the non-ASCII character is ignored. The string must
be ``unicode``.
>>> transliterate('älämölö')
>>> transliterate('Ærøskøbing')
normalized = unicodedata.normalize('NFKD', string)
return normalized.encode('ascii', 'ignore').decode('ascii')
def underscore(word):
Make an underscored, lowercase form from the expression in the string.
>>> underscore("DeviceType")
As a rule of thumb you can think of :func:`underscore` as the inverse of
:func:`camelize`, though there are cases where that does not hold::
>>> camelize(underscore("IOError"))
word = re.sub(r"([A-Z]+)([A-Z][a-z])", r'\1_\2', word)
word = re.sub(r"([a-z\d])([A-Z])", r'\1_\2', word)
word = word.replace("-", "_")
return word.lower()
_irregular('person', 'people')
_irregular('man', 'men')
_irregular('human', 'humans')
_irregular('child', 'children')
_irregular('sex', 'sexes')
_irregular('move', 'moves')
_irregular('cow', 'kine')
_irregular('zombie', 'zombies')
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