File: inflect.py

package info (click to toggle)
python-pattern 2.6%2Bgit20150109-2
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 78,464 kB
  • ctags: 9,537
  • sloc: python: 53,863; xml: 11,965; ansic: 2,318; makefile: 94
file content (581 lines) | stat: -rw-r--r-- 29,115 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
#### PATTERN | DE | INFLECT ########################################################################
# -*- coding: utf-8 -*-
# Copyright (c) 2012 University of Antwerp, Belgium
# Author: Tom De Smedt <tom@organisms.be>
# License: BSD (see LICENSE.txt for details).

####################################################################################################
# Regular expressions-based rules for German word inflection:
# - pluralization and singularization of nouns and adjectives,
# - conjugation of verbs,
# - attributive and predicative of adjectives,
# - comparative and superlative of adjectives.

# Accuracy (measured on CELEX German morphology word forms):
# 75% for gender()
# 72% for pluralize()
# 84% for singularize() (for nominative)
# 87% for Verbs.find_lemma()
# 87% for Verbs.find_lexeme()
# 98% for predicative

import os
import sys
import re

try:
    MODULE = os.path.dirname(os.path.realpath(__file__))
except:
    MODULE = ""
    
sys.path.insert(0, os.path.join(MODULE, "..", "..", "..", ".."))

from pattern.text import Verbs as _Verbs
from pattern.text import (
    INFINITIVE, PRESENT, PAST, FUTURE,
    FIRST, SECOND, THIRD,
    SINGULAR, PLURAL, SG, PL,
    INDICATIVE, IMPERATIVE, SUBJUNCTIVE,
    PROGRESSIVE,
    PARTICIPLE, GERUND
)

sys.path.pop(0)

VERB, NOUN, ADJECTIVE, ADVERB = "VB", "NN", "JJ", "RB"

VOWELS = "aeiouy"
re_vowel = re.compile(r"a|e|i|o|u|y", re.I)
is_vowel = lambda ch: ch in VOWELS

#### ARTICLE #######################################################################################
# German inflection of depends on gender, role and number + the determiner (if any).

# Inflection gender.
# Masculine is the most common, so it is the default for all functions.
MASCULINE, FEMININE, NEUTER, PLURAL = \
    MALE, FEMALE, NEUTRAL, PLURAL = \
        M, F, N, PL = "m", "f", "n", "p"

# Inflection role.
# - nom = subject, "Der Hund bellt" (the dog barks).
# - acc = object, "Das Mädchen küsst den Hund" (the girl kisses the dog).
# - dat = object (indirect), "Der Mann gibt einen Knochen zum Hund" (the man gives the dog a bone).
# - gen = property, "die Knochen des Hundes" (the dog's bone).
NOMINATIVE, ACCUSATIVE, DATIVE, GENITIVE = SUBJECT, OBJECT, INDIRECT, PROPERTY = \
    "nominative", "accusative", "dative", "genitive"

article_definite = {
    ("m", "nom"): "der", ("f", "nom"): "die", ("n", "nom"): "das", ("p", "nom"): "die",
    ("m", "acc"): "den", ("f", "acc"): "die", ("n", "acc"): "das", ("p", "acc"): "die",
    ("m", "dat"): "dem", ("f", "dat"): "der", ("n", "dat"): "dem", ("p", "dat"): "den",
    ("m", "gen"): "des", ("f", "gen"): "der", ("n", "gen"): "des", ("p", "gen"): "der",
}

article_indefinite = {
    ("m", "nom"): "ein"  , ("f", "nom"): "eine" , ("n", "nom"): "ein"  , ("p", "nom"): "eine",
    ("m", "acc"): "einen", ("f", "acc"): "eine" , ("n", "acc"): "ein"  , ("p", "acc"): "eine",
    ("m", "dat"): "einem", ("f", "dat"): "einer", ("n", "dat"): "einem", ("p", "dat"): "einen",
    ("m", "gen"): "eines", ("f", "gen"): "einer", ("n", "gen"): "eines", ("p", "gen"): "einer",
}

def definite_article(word, gender=MALE, role=SUBJECT):
    """ Returns the definite article (der/die/das/die) for a given word.
    """
    return article_definite.get((gender[:1].lower(), role[:3].lower()))

def indefinite_article(word, gender=MALE, role=SUBJECT):
    """ Returns the indefinite article (ein) for a given word.
    """
    return article_indefinite.get((gender[:1].lower(), role[:3].lower()))

DEFINITE   = "definite"
INDEFINITE = "indefinite"

def article(word, function=INDEFINITE, gender=MALE, role=SUBJECT):
    """ Returns the indefinite (ein) or definite (der/die/das/die) article for the given word.
    """
    return function == DEFINITE \
       and definite_article(word, gender, role) \
        or indefinite_article(word, gender, role)
_article = article

def referenced(word, article=INDEFINITE, gender=MALE, role=SUBJECT):
    """ Returns a string with the article + the word.
    """
    return "%s %s" % (_article(word, article, gender, role), word)

#### GENDER #########################################################################################

gender_masculine = (
    "ant", "ast", "ich", "ig", "ismus", "ling", "or", "us"
)
gender_feminine = (
    "a", "anz", "ei", "enz", "heit", "ie", "ik", "in", "keit", "schaf", "sion", "sis", 
    u"tät", "tion", "ung", "ur"
)
gender_neuter = (
    "chen", "icht", "il", "it", "lein", "ma", "ment", "tel", "tum", "um","al", "an", "ar", 
    u"ät", "ent", "ett", "ier", "iv", "o", "on", "nis", "sal"
)
gender_majority_vote = {
    MASCULINE: (
        "ab", "af", "ag", "ak", "am", "an", "ar", "at", "au", "ch", "ck", "eb", "ef", "eg", 
        "el", "er", "es", "ex", "ff", "go", "hn", "hs", "ib", "if", "ig", "ir", "kt", "lf", 
        "li", "ll", "lm", "ls", "lt", "mi", "nd", "nk", "nn", "nt", "od", "of", "og", "or", 
        "pf", "ph", "pp", "ps", "rb", "rd", "rf", "rg", "ri", "rl", "rm", "rr", "rs", "rt", 
        "rz", "ss", "st", "tz", "ub", "uf", "ug", "uh", "un", "us", "ut", "xt", "zt"
    ), 
    FEMININE: (
        "be", "ce", "da", "de", "dt", "ee", "ei", "et", "eu", "fe", "ft", "ge", "he", "hr", 
        "ht", "ia", "ie", "ik", "in", "it", "iz", "ka", "ke", "la", "le", "me", "na", "ne", 
        "ng", "nz", "on", "pe", "ra", "re", "se", "ta", "te", "ue", "ur", "ve", "ze"
    ), 

    NEUTER: (
        "ad", "al", "as", "do", "ed", "eh", "em", "en", "hl", "id", "il", "im", "io", "is", 
        "iv", "ix", "ld", "lk", "lo", "lz", "ma", "md", "mm", "mt", "no", "ns", "ol", "om", 
        "op", "os", "ot", "pt", "rk", "rn", "ro", "to", "tt", "ul", "um", "uz"
    )
}

def gender(word, pos=NOUN):
    """ Returns the gender (MALE, FEMALE or NEUTRAL) for nouns (majority vote).
        Returns None for words that are not nouns.
    """
    w = word.lower()
    if pos == NOUN:
        # Default rules (baseline = 32%).
        if w.endswith(gender_masculine):
            return MASCULINE
        if w.endswith(gender_feminine):
            return FEMININE
        if w.endswith(gender_neuter):
            return NEUTER
        # Majority vote.
        for g in gender_majority_vote:
            if w.endswith(gender_majority_vote[g]):
                return g

#### PLURALIZE ######################################################################################

plural_inflections = [
    ("aal", u"äle"   ), ("aat",  "aaten"), ( "abe",  "aben" ), ("ach", u"ächer"), ("ade",  "aden"  ),
    ("age",  "agen"  ), ("ahn",  "ahnen"), ( "ahr",  "ahre" ), ("akt",  "akte" ), ("ale",  "alen"  ),
    ("ame",  "amen"  ), ("amt", u"ämter"), ( "ane",  "anen" ), ("ang", u"änge" ), ("ank", u"änke"  ),
    ("ann", u"änner" ), ("ant",  "anten"), ( "aph",  "aphen"), ("are",  "aren" ), ("arn",  "arne"  ),
    ("ase",  "asen"  ), ("ate",  "aten" ), ( "att", u"ätter"), ("atz", u"ätze" ), ("aum",  "äume"  ),
    ("aus", u"äuser" ), ("bad", u"bäder"), ( "bel",  "bel"  ), ("ben",  "ben"  ), ("ber",  "ber"   ),
    ("bot",  "bote"  ), ("che",  "chen" ), ( "chs",  "chse" ), ("cke",  "cken" ), ("del",  "del"   ),
    ("den",  "den"   ), ("der",  "der"  ), ( "ebe",  "ebe"  ), ("ede",  "eden" ), ("ehl",  "ehle"  ),
    ("ehr",  "ehr"   ), ("eil",  "eile" ), ( "eim",  "eime" ), ("eis",  "eise" ), ("eit",  "eit"   ),
    ("ekt",  "ekte"  ), ("eld",  "elder"), ( "ell",  "elle" ), ("ene",  "enen" ), ("enz",  "enzen" ),
    ("erd",  "erde"  ), ("ere",  "eren" ), ( "erk",  "erke" ), ("ern",  "erne" ), ("ert",  "erte"  ),
    ("ese",  "esen"  ), ("ess",  "esse" ), ( "est",  "este" ), ("etz",  "etze" ), ("eug",  "euge"  ),
    ("eur",  "eure"  ), ("fel",  "fel"  ), ( "fen",  "fen"  ), ("fer",  "fer"  ), ("ffe",  "ffen"  ),
    ("gel",  "gel"   ), ("gen",  "gen"  ), ( "ger",  "ger"  ), ("gie",  "gie"  ), ("hen",  "hen"   ),
    ("her",  "her"   ), ("hie",  "hien" ), ( "hle",  "hlen" ), ("hme",  "hmen" ), ("hne",  "hnen"  ),
    ("hof", u"höfe"  ), ("hre",  "hren" ), ( "hrt",  "hrten"), ("hse",  "hsen" ), ("hte",  "hten"  ),
    ("ich",  "iche"  ), ("ick",  "icke" ), ( "ide",  "iden" ), ("ieb",  "iebe" ), ("ief",  "iefe"  ),
    ("ieg",  "iege"  ), ("iel",  "iele" ), ( "ien",  "ium"  ), ("iet",  "iete" ), ("ife",  "ifen"  ),
    ("iff",  "iffe"  ), ("ift",  "iften"), ( "ige",  "igen" ), ("ika",  "ikum" ), ("ild",  "ilder" ),
    ("ilm",  "ilme"  ), ("ine",  "inen" ), ( "ing",  "inge" ), ("ion",  "ionen"), ("ise",  "isen"  ),
    ("iss",  "isse"  ), ("ist",  "isten"), ( "ite",  "iten" ), ("itt",  "itte" ), ("itz",  "itze"  ),
    ("ium",  "ium"   ), ("kel",  "kel"  ), ( "ken",  "ken"  ), ("ker",  "ker"  ), ("lag", u"läge"  ),
    ("lan", u"läne"  ), ("lar",  "lare" ), ( "lei",  "leien"), ("len",  "len"  ), ("ler",  "ler"   ),
    ("lge",  "lgen"  ), ("lie",  "lien" ), ( "lle",  "llen" ), ("mel",  "mel"  ), ("mer",  "mer"   ),
    ("mme",  "mmen"  ), ("mpe",  "mpen" ), ( "mpf",  "mpfe" ), ("mus",  "mus"  ), ("mut",  "mut"   ),
    ("nat",  "nate"  ), ("nde",  "nden" ), ( "nen",  "nen"  ), ("ner",  "ner"  ), ("nge",  "ngen"  ),
    ("nie",  "nien"  ), ("nis",  "nisse"), ( "nke",  "nken" ), ("nkt",  "nkte" ), ("nne",  "nnen"  ),
    ("nst",  "nste"  ), ("nte",  "nten" ), ( "nze",  "nzen" ), ("ock", u"öcke" ), ("ode",  "oden"  ),
    ("off",  "offe"  ), ("oge",  "ogen" ), ( "ohn", u"öhne" ), ("ohr",  "ohre" ), ("olz", u"ölzer" ),
    ("one",  "onen"  ), ("oot",  "oote" ), ( "opf", u"öpfe" ), ("ord",  "orde" ), ("orm",  "ormen" ),
    ("orn", u"örner" ), ("ose",  "osen" ), ( "ote",  "oten" ), ("pel",  "pel"  ), ("pen",  "pen"   ),
    ("per",  "per"   ), ("pie",  "pien" ), ( "ppe",  "ppen" ), ("rag", u"räge" ), ("rau", u"raün"  ),
    ("rbe",  "rben"  ), ("rde",  "rden" ), ( "rei",  "reien"), ("rer",  "rer"  ), ("rie",  "rien"  ),
    ("rin",  "rinnen"), ("rke",  "rken" ), ( "rot",  "rote" ), ("rre",  "rren" ), ("rte",  "rten"  ),
    ("ruf",  "rufe"  ), ("rzt",  "rzte" ), ( "sel",  "sel"  ), ("sen",  "sen"  ), ("ser",  "ser"   ),
    ("sie",  "sien"  ), ("sik",  "sik"  ), ( "sse",  "ssen" ), ("ste",  "sten" ), ("tag",  "tage"  ),
    ("tel",  "tel"   ), ("ten",  "ten"  ), ( "ter",  "ter"  ), ("tie",  "tien" ), ("tin",  "tinnen"),
    ("tiv",  "tive"  ), ("tor",  "toren"), ( "tte",  "tten" ), ("tum",  "tum"  ), ("tur",  "turen" ),
    ("tze",  "tzen"  ), ("ube",  "uben" ), ( "ude",  "uden" ), ("ufe",  "ufen" ), ("uge",  "ugen"  ),
    ("uhr",  "uhren" ), ("ule",  "ulen" ), ( "ume",  "umen" ), ("ung",  "ungen"), ("use",  "usen"  ),
    ("uss", u"üsse"  ), ("ute",  "uten" ), ( "utz",  "utz"  ), ("ver",  "ver"  ), ("weg",  "wege"  ),
    ("zer",  "zer"   ), ("zug", u"züge" ), (u"ück", u"ücke" )
]

def pluralize(word, pos=NOUN, gender=MALE, role=SUBJECT, custom={}):
    """ Returns the plural of a given word.
        The inflection is based on probability rather than gender and role.
    """
    w = word.lower().capitalize()
    if word in custom:
        return custom[word]
    if pos == NOUN:
        for a, b in plural_inflections:
            if w.endswith(a):
                return w[:-len(a)] + b
        # Default rules (baseline = 69%).
        if w.startswith("ge"):
            return w
        if w.endswith("gie"):
            return w
        if w.endswith("e"):
            return w + "n"
        if w.endswith("ien"):
            return w[:-2] + "um"
        if w.endswith(("au", "ein", "eit", "er", "en", "el", "chen", "mus", u"tät", "tik", "tum", "u")):
            return w
        if w.endswith(("ant", "ei", "enz", "ion", "ist", "or", "schaft", "tur", "ung")):
            return w + "en"
        if w.endswith("in"):
            return w + "nen"
        if w.endswith("nis"):
            return w + "se"
        if w.endswith(("eld", "ild", "ind")):
            return w + "er"
        if w.endswith("o"):
            return w + "s"
        if w.endswith("a"):
            return w[:-1] + "en"
        # Inflect common umlaut vowels: Kopf => Köpfe.
        if w.endswith(("all", "and", "ang", "ank", "atz", "auf", "ock", "opf", "uch", "uss")):
            umlaut = w[-3]
            umlaut = umlaut.replace("a", u"ä")
            umlaut = umlaut.replace("o", u"ö")
            umlaut = umlaut.replace("u", u"ü")
            return w[:-3] + umlaut + w[-2:] + "e"
        for a, b in (
          ("ag",  u"äge"), 
          ("ann", u"änner"), 
          ("aum", u"äume"), 
          ("aus", u"äuser"), 
          ("zug", u"züge")):
            if w.endswith(a):
                return w[:-len(a)] + b
        return w + "e"
    return w

#### SINGULARIZE ###################################################################################

singular_inflections = [
    ( "innen", "in" ), (u"täten", u"tät"), ( "ahnen",  "ahn"), ( "enten", "ent"), (u"räser",  "ras"),
    ( "hrten", "hrt"), (u"ücher",  "uch"), (u"örner",  "orn"), (u"änder", "and"), (u"ürmer",  "urm"),
    ( "ahlen", "ahl"), ( "uhren",  "uhr"), (u"ätter",  "att"), ( "suren", "sur"), ( "chten",  "cht"),
    ( "kuren", "kur"), ( "erzen",  "erz"), (u"güter",  "gut"), ( "soren", "sor"), (u"änner",  "ann"),
    (u"äuser", "aus"), ( "taten",  "tat"), ( "isten",  "ist"), (u"bäder", "bad"), (u"ämter",  "amt"),
    ( "eiten", "eit"), ( "raten",  "rat"), ( "ormen",  "orm"), ( "ionen", "ion"), ( "nisse",  "nis"),
    (u"ölzer", "olz"), ( "ungen",  "ung"), (u"läser",  "las"), (u"ächer", "ach"), ( "urten",  "urt"),
    ( "enzen", "enz"), ( "aaten",  "aat"), ( "aphen",  "aph"), (u"öcher", "och"), (u"türen", u"tür"),
    ( "sonen", "son"), (u"ühren", u"ühr"), (u"ühner",  "uhn"), ( "toren", "tor"), (u"örter",  "ort"),
    ( "anten", "ant"), (u"räder",  "rad"), ( "turen",  "tur"), (u"äuler", "aul"), ( u"änze",  "anz"),
    (  "tten", "tte"), (  "mben",  "mbe"), ( u"ädte",  "adt"), (  "llen", "lle"), (  "ysen",  "yse"),
    (  "rben", "rbe"), (  "hsen",  "hse"), ( u"raün",  "rau"), (  "rven", "rve"), (  "rken",  "rke"),
    ( u"ünge", "ung"), ( u"üten", u"üte"), (  "usen",  "use"), (  "tien", "tie"), ( u"läne",  "lan"),
    (  "iben", "ibe"), (  "ifen",  "ife"), (  "ssen",  "sse"), (  "gien", "gie"), (  "eten",  "ete"),
    (  "rden", "rde"), ( u"öhne",  "ohn"), ( u"ärte",  "art"), (  "ncen", "nce"), ( u"ünde",  "und"),
    (  "uben", "ube"), (  "lben",  "lbe"), ( u"üsse",  "uss"), (  "agen", "age"), ( u"räge",  "rag"),
    (  "ogen", "oge"), (  "anen",  "ane"), (  "sken",  "ske"), (  "eden", "ede"), ( u"össe",  "oss"),
    ( u"ürme", "urm"), (  "ggen",  "gge"), ( u"üren", u"üre"), (  "nten", "nte"), ( u"ühle", u"ühl"),
    ( u"änge", "ang"), (  "mmen",  "mme"), (  "igen",  "ige"), (  "nken", "nke"), ( u"äcke",  "ack"),
    (  "oden", "ode"), (  "oben",  "obe"), ( u"ähne",  "ahn"), ( u"änke", "ank"), (  "inen",  "ine"),
    (  "seen", "see"), ( u"äfte",  "aft"), (  "ulen",  "ule"), ( u"äste", "ast"), (  "hren",  "hre"),
    ( u"öcke", "ock"), (  "aben",  "abe"), ( u"öpfe",  "opf"), (  "ugen", "uge"), (  "lien",  "lie"),
    ( u"ände", "and"), ( u"ücke", u"ück"), (  "asen",  "ase"), (  "aden", "ade"), (  "dien",  "die"),
    (  "aren", "are"), (  "tzen",  "tze"), ( u"züge",  "zug"), ( u"üfte", "uft"), (  "hien",  "hie"),
    (  "nden", "nde"), ( u"älle",  "all"), (  "hmen",  "hme"), (  "ffen", "ffe"), (  "rmen",  "rma"),
    (  "olen", "ole"), (  "sten",  "ste"), (  "amen",  "ame"), ( u"höfe", "hof"), ( u"üste",  "ust"),
    (  "hnen", "hne"), ( u"ähte",  "aht"), (  "umen",  "ume"), (  "nnen", "nne"), (  "alen",  "ale"),
    (  "mpen", "mpe"), (  "mien",  "mie"), (  "rten",  "rte"), (  "rien", "rie"), ( u"äute",  "aut"),
    (  "uden", "ude"), (  "lgen",  "lge"), (  "ngen",  "nge"), (  "iden", "ide"), ( u"ässe",  "ass"),
    (  "osen", "ose"), (  "lken",  "lke"), (  "eren",  "ere"), ( u"üche", "uch"), ( u"lüge",  "lug"),
    (  "hlen", "hle"), (  "isen",  "ise"), ( u"ären", u"äre"), ( u"töne", "ton"), (  "onen",  "one"),
    (  "rnen", "rne"), ( u"üsen", u"üse"), ( u"haün",  "hau"), (  "pien", "pie"), (  "ihen",  "ihe"),
    ( u"ürfe", "urf"), (  "esen",  "ese"), ( u"ätze",  "atz"), (  "sien", "sie"), ( u"läge",  "lag"),
    (  "iven", "ive"), ( u"ämme",  "amm"), ( u"äufe",  "auf"), (  "ppen", "ppe"), (  "enen",  "ene"),
    (  "lfen", "lfe"), ( u"äume",  "aum"), (  "nien",  "nie"), (  "unen", "une"), (  "cken",  "cke"),
    (  "oten", "ote"), (   "mie",  "mie"), (   "rie",  "rie"), (   "sis", "sen"), (   "rin",  "rin"),
    (   "ein", "ein"), (   "age",  "age"), (   "ern",  "ern"), (   "ber", "ber"), (   "ion",  "ion"),
    (   "inn", "inn"), (   "ben",  "ben"), (  u"äse", u"äse"), (   "eis", "eis"), (   "hme",  "hme"),
    (   "iss", "iss"), (   "hen",  "hen"), (   "fer",  "fer"), (   "gie", "gie"), (   "fen",  "fen"),
    (   "her", "her"), (   "ker",  "ker"), (   "nie",  "nie"), (   "mer", "mer"), (   "ler",  "ler"),
    (   "men", "men"), (   "ass",  "ass"), (   "ner",  "ner"), (   "per", "per"), (   "rer",  "rer"),
    (   "mus", "mus"), (   "abe",  "abe"), (   "ter",  "ter"), (   "ser", "ser"), (  u"äle",  "aal"),
    (   "hie", "hie"), (   "ger",  "ger"), (   "tus",  "tus"), (   "gen", "gen"), (   "ier",  "ier"),
    (   "ver", "ver"), (   "zer",  "zer"),
]

singular = {
    u"Löwen": u"Löwe",
}

def singularize(word, pos=NOUN, gender=MALE, role=SUBJECT, custom={}):
    """ Returns the singular of a given word.
        The inflection is based on probability rather than gender and role.
    """
    w = word.lower().capitalize()
    if word in custom:
        return custom[word]
    if word in singular:
        return singular[word]
    if pos == NOUN:
        for a, b in singular_inflections:
            if w.endswith(a):
                return w[:-len(a)] + b
        # Default rule: strip known plural suffixes (baseline = 51%).
        for suffix in ("nen", "en", "n", "e", "er", "s"):
            if w.endswith(suffix):
                w = w[:-len(suffix)]
                break
        # Corrections (these add about 1% accuracy):
        if w.endswith(("rr", "rv", "nz")):
            return w + "e"
        return w
    return w

#### VERB CONJUGATION ##############################################################################
# The verb table was trained on CELEX and contains the top 2000 most frequent verbs.

prefix_inseparable = (
    "be", "emp", "ent", "er", "ge", "miss", u"über", "unter", "ver", "voll", "wider", "zer"
)
prefix_separable = (
    "ab", "an", "auf", "aus", "bei", "durch", "ein", "fort", "mit", "nach", "vor", "weg", 
    u"zurück", "zusammen", "zu", "dabei", "daran", "da", "empor", "entgegen", "entlang", 
    "fehl", "fest", u"gegenüber", "gleich", "herab", "heran", "herauf", "heraus", "herum", 
    "her", "hinweg", "hinzu", "hin", "los", "nieder", "statt", "umher", "um", "weg", 
    "weiter", "wieder", "zwischen"
) + ( # There are many more...
     "dort", "fertig", "frei", "gut", "heim", "hoch", "klein", "klar", "nahe", "offen", "richtig"
)
prefixes = prefix_inseparable + prefix_separable

def encode_sz(s):
    return s.replace(u"ß", "ss")
def decode_sz(s):
    return s.replace("ss", u"ß")

class Verbs(_Verbs):
    
    def __init__(self):
        _Verbs.__init__(self, os.path.join(MODULE, "de-verbs.txt"),
            language = "de",
              format = [0, 1, 2, 3, 4, 5, 8, 17, 18, 19, 20, 21, 24, 52, 54, 53, 55, 56, 58, 59, 67, 68, 70, 71],
             default = {6: 4, 22: 20, 57: 55, 60: 58, 69: 67, 72: 70}
            )
    
    def find_lemma(self, verb):
        """ Returns the base form of the given inflected verb, using a rule-based approach.
        """
        v = verb.lower()
        # Common prefixes: be-finden and emp-finden probably inflect like finden.
        if not (v.startswith("ge") and v.endswith("t")): # Probably gerund.
            for prefix in prefixes:
                if v.startswith(prefix) and v[len(prefix):] in self.inflections:
                    return prefix + self.inflections[v[len(prefix):]]
        # Common sufixes: setze nieder => niedersetzen.
        b, suffix = " " in v and v.split()[:2] or  (v, "")
        # Infinitive -ln: trommeln.
        if b.endswith(("ln", "rn")):
            return b
        # Lemmatize regular inflections.
        for x in ("test", "est", "end", "ten", "tet", "en", "et", "te", "st", "e", "t"):
            if b.endswith(x): b = b[:-len(x)]; break
        # Subjunctive: hielte => halten, schnitte => schneiden.
        for x, y in (
          ("ieb",  "eib"), ( "ied", "eid"), ( "ief",  "auf" ), ( "ieg", "eig" ), ("iel", "alt"), 
          ("ien",  "ein"), ("iess", "ass"), (u"ieß", u"aß"  ), ( "iff", "eif" ), ("iss", "eiss"), 
          (u"iß", u"eiß"), (  "it", "eid"), ( "oss",  "iess"), (u"öss", "iess")):
            if b.endswith(x): b = b[:-len(x)] + y; break
        b = b.replace("eeiss", "eiss")
        b = b.replace("eeid", "eit")
        # Subjunctive: wechselte => wechseln
        if not b.endswith(("e", "l")) and not (b.endswith("er") and len(b) >= 3 and not b[-3] in VOWELS):
            b = b + "e"
        # abknallst != abknalln => abknallen
        if b.endswith(("hl", "ll", "ul", "eil")):
            b = b + "e"
        # Strip ge- from (likely) gerund:
        if b.startswith("ge") and v.endswith("t"):
            b = b[2:]
        # Corrections (these add about 1.5% accuracy):
        if b.endswith(("lnde", "rnde")):
            b = b[:-3]
        if b.endswith(("ae", "al", u"öe", u"üe")):
            b = b.rstrip("e") + "te"
        if b.endswith(u"äl"):
            b = b + "e"
        return suffix + b + "n"

    def find_lexeme(self, verb):
        """ For a regular verb (base form), returns the forms using a rule-based approach.
        """
        v = verb.lower()
        # Stem = infinitive minus -en, -ln, -rn.
        b = b0 = re.sub("en$", "", re.sub("ln$", "l", re.sub("rn$", "r", v)))
        # Split common prefixes.
        x, x1, x2 = "", "", ""
        for prefix in prefix_separable:
            if v.startswith(prefix):
                b, x = b[len(prefix):], prefix
                x1 = (" " + x).rstrip()
                x2 = x + "ge"
                break
        # Present tense 1sg and subjunctive -el: handeln => ich handle, du handlest.
        pl = b.endswith("el") and b[:-2]+"l" or b
        # Present tense 1pl -el: handeln => wir handeln
        pw = v.endswith(("ln", "rn")) and v or b+"en"
        # Present tense ending in -d or -t gets -e:
        pr = b.endswith(("d", "t")) and b+"e" or b
        # Present tense 2sg gets -st, unless stem ends with -s or -z.
        p2 = pr.endswith(("s","z")) and pr+"t" or pr+"st"
        # Present participle: spiel + -end, arbeiten + -d:
        pp = v.endswith(("en", "ln", "rn")) and v+"d" or v+"end"
        # Past tense regular:
        pt = encode_sz(pr) + "t"
        # Past participle: haushalten => hausgehalten
        ge = (v.startswith(prefix_inseparable) or b.endswith(("r","t"))) and pt or "ge"+pt
        ge = x and x+"ge"+pt or ge
        # Present subjunctive: stem + -e, -est, -en, -et:
        s1 = encode_sz(pl)
        # Past subjunctive: past (usually with Umlaut) + -e, -est, -en, -et:
        s2 = encode_sz(pt)
        # Construct the lexeme:
        lexeme = a = [
            v, 
            pl+"e"+x1, p2+x1, pr+"t"+x1, pw+x1, pr+"t"+x1, pp,             # present
            pt+"e"+x1, pt+"est"+x1, pt+"e"+x1, pt+"en"+x1, pt+"et"+x1, ge, # past
            b+"e"+x1, pr+"t"+x1, x+pw,                                     # imperative
            s1+"e"+x1, s1+"est"+x1, s1+"en"+x1, s1+"et"+x1,                # subjunctive I
            s2+"e"+x1, s2+"est"+x1, s2+"en"+x1, s2+"et"+x1                 # subjunctive II
        ]
        # Encode Eszett (ß) and attempt to retrieve from the lexicon.
        # Decode Eszett for present and imperative.
        if encode_sz(v) in self:
            a = self[encode_sz(v)]
            a = [decode_sz(v) for v in a[:7]] + a[7:13] + [decode_sz(v) for v in a[13:20]] + a[20:]
        # Since the lexicon does not contain imperative for all verbs, don't simply return it.
        # Instead, update the rule-based lexeme with inflections from the lexicon.
        return [a[i] or lexeme[i] for i in range(len(a))]

    def tenses(self, verb, parse=True):
        """ Returns a list of possible tenses for the given inflected verb.
        """
        tenses = _Verbs.tenses(self, verb, parse)
        if len(tenses) == 0:
            # auswirkte => wirkte aus
            for prefix in prefix_separable:
                if verb.startswith(prefix):
                    tenses = _Verbs.tenses(self, verb[len(prefix):] + " " + prefix, parse)
                    break
        return tenses

verbs = Verbs()

conjugate, lemma, lexeme, tenses = \
    verbs.conjugate, verbs.lemma, verbs.lexeme, verbs.tenses

#### ATTRIBUTIVE & PREDICATIVE #####################################################################

# Strong inflection: no article.
adjectives_strong = {
    ("m", "nom"): "er", ("f", "nom"): "e" , ("n", "nom"): "es", ("p", "nom"): "e",
    ("m", "acc"): "en", ("f", "acc"): "e" , ("n", "acc"): "es", ("p", "acc"): "e",
    ("m", "dat"): "em", ("f", "dat"): "er", ("n", "dat"): "em", ("p", "dat"): "en",
    ("m", "gen"): "en", ("f", "gen"): "er", ("n", "gen"): "en", ("p", "gen"): "er",
}

# Mixed inflection: after indefinite article ein & kein and possessive determiners.
adjectives_mixed = {
    ("m", "nom"): "er", ("f", "nom"): "e" , ("n", "nom"): "es", ("p", "nom"): "en",
    ("m", "acc"): "en", ("f", "acc"): "e" , ("n", "acc"): "es", ("p", "acc"): "en",
    ("m", "dat"): "en", ("f", "dat"): "en", ("n", "dat"): "en", ("p", "dat"): "en",
    ("m", "gen"): "en", ("f", "gen"): "en", ("n", "gen"): "en", ("p", "gen"): "en",
}

# Weak inflection: after definite article.
adjectives_weak = {
    ("m", "nom"): "e",  ("f", "nom"): "e" , ("n", "nom"): "e",  ("p", "nom"): "en",
    ("m", "acc"): "en", ("f", "acc"): "e" , ("n", "acc"): "e",  ("p", "acc"): "en",
    ("m", "dat"): "en", ("f", "dat"): "en", ("n", "dat"): "en", ("p", "dat"): "en",
    ("m", "gen"): "en", ("f", "gen"): "en", ("n", "gen"): "en", ("p", "gen"): "en",
}

# Uninflected + exceptions.
adjective_attributive = {
    "etwas" : "etwas",
    "genug" : "genug",
    "viel"  : "viel",
    "wenig" : "wenig"
}

def attributive(adjective, gender=MALE, role=SUBJECT, article=None):
    """ For a predicative adjective, returns the attributive form (lowercase).
        In German, the attributive is formed with -e, -em, -en, -er or -es,
        depending on gender (masculine, feminine, neuter or plural) and role
        (nominative, accusative, dative, genitive).
    """
    w, g, c, a = \
        adjective.lower(), gender[:1].lower(), role[:3].lower(), article and article.lower() or None
    if w in adjective_attributive:
        return adjective_attributive[w]
    if a is None \
    or a in ("mir", "dir", "ihm") \
    or a in ("ein", "etwas", "mehr") \
    or a.startswith(("all", "mehrer", "wenig", "viel")):
        return w + adjectives_strong.get((g, c), "")
    if a.startswith(("ein", "kein")) \
    or a.startswith(("mein", "dein", "sein", "ihr", "Ihr", "unser", "euer")):
        return w + adjectives_mixed.get((g, c), "")
    if a in ("arm", "alt", "all", "der", "die", "das", "den", "dem", "des") \
    or a.startswith((
      "derselb", "derjenig", "jed", "jeglich", "jen", "manch", 
      "dies", "solch", "welch")):
        return w + adjectives_weak.get((g, c), "")
    # Default to strong inflection.
    return w + adjectives_strong.get((g, c), "")

def predicative(adjective):
    """ Returns the predicative adjective (lowercase).
        In German, the attributive form preceding a noun is always used:
        "ein kleiner Junge" => strong, masculine, nominative,
        "eine schöne Frau" => mixed, feminine, nominative,
        "der kleine Prinz" => weak, masculine, nominative, etc.
        The predicative is useful for lemmatization.
    """
    w = adjective.lower()
    if len(w) > 3:
        for suffix in ("em", "en", "er", "es", "e"):
            if w.endswith(suffix):
                b = w[:max(-len(suffix), -(len(w)-3))]
                if b.endswith("bl"): # plausibles => plausibel
                    b = b[:-1] + "el"
                if b.endswith("pr"): # propres => proper
                    b = b[:-1] + "er"
                return b
    return w

#### COMPARATIVE & SUPERLATIVE #####################################################################

COMPARATIVE = "er"
SUPERLATIVE = "st"

def grade(adjective, suffix=COMPARATIVE):
    """ Returns the comparative or superlative form of the given (inflected) adjective.
    """
    b = predicative(adjective)
    # groß => großt, schön => schönst
    if suffix == SUPERLATIVE and b.endswith(("s", u"ß")):
        suffix = suffix[1:]
    # große => großere, schönes => schöneres
    return adjective[:len(b)] + suffix + adjective[len(b):]

def comparative(adjective):
    return grade(adjective, COMPARATIVE)

def superlative(adjective):
    return grade(adjective, SUPERLATIVE)

#print(comparative(u"schönes"))
#print(superlative(u"schönes"))
#print(superlative(u"große"))