Contemporary Persian Inflectional Analyzer

Analyze Informal and Formal words of contemporary Persian.

Install

pip install cpia

Usage

>>> from cpia import FarsiAnalyzer, Converter
>>> farsi = FarsiAnalyzer()

>>> farsi.inflect("کتاب‌هایشان")
['اسمعا=کتاب+جها+وشخصی۶+رسمی']

>>> farsi.inflect("بشینین")
['التزامی=نشین+ش۵', 'امری=نشین+ش۵']

>>> farsi.generate("امری=گو+مفرد+رسمی")
['بگو']

>>> print(farsi.generate('ف.ح.ا=خور+ش۱+ومفعولی۲')[0])
می‌‌خورمت

>>> farsi.lemmatize(farsi.inflect("میچرخوندمش")[0])
{'lemma': 'چرخوند',
 'pos': 'ف.م.ا',
 'register': 'غیررسمی',
 'long_pos': 'فعل ماضی استمراری'}

>>> converter = Converter(farsi)
>>> print(converter.convert("میچرخوندمش", "formal")[0])
می‌چرخاندم

For understanding abbreviations used in inflection rules:

>>> farsi.show_help()
🔹  ف.م.ب 👈 فعل ماضی بعید*
🔹  ف.م.ال 👈 فعل ماضی التزامی*
🔹  ف.م.ا.ب 👈 فعل ماضی ابعد*
🔹  ف.آ 👈 فعل مستقبل (آینده)*
🔹  اسمعام 👈 اسم عام
          ...

Other than standard fst for inflection and generation fst for generating words from rules, cpia has secondary fsts. The main fst is enough for almost all tasks but the secondary fsts can be used for noisy informal Out-Of-Vocabulary words, they normally can produce a lot of useless inflections. They are only useful for special cases. Use them only if you know what you want. If you need to use other fsts, just pass their name as argument to the FarsiAnalyzer constructor:

>>> farsi = FarsiAnalyzer("homophone")

Fsts

Name	word	output
standard	برم	<اسمعام=بره+وشخصی۱> <اسمعام=بر+هم> <اسمعام=بر+وشخصی۱+رسمی> <اسمعام=بر+وربطی۱+رسمی> <اسمعام=برم+رسمی> <حضاف=بر+وشخصی۱+رسمی> <التزامی=ر+ش۱> <امری=رم+مفرد+رسمی>

Secondary Fsts

Name	word	output
homophone	مسؤول مسئول مسیول	<اسمعام=مسئول+رسمی>
phone_change (avaee)	شیطون	<اسمعام=شیطان>
expressive	چرااااااا	<اسمعام=چرا+رسمی>
splitter	چهاربعدی	<شماره=چهار+رسمی> <صفت=بعدی+رسمی>

Evaluation

The analyzer is not aware of context but the output should provide all possible inflections for all possible contexts. Eval dataset is in eval folder. For 1786 unique words extracted from dataset analyzer produced 3,704 inflections rules. Here are the shortcomings counted based on their occurances.

register	OOV	OO-Rules	homophone / Ezafeh Const.	stucking words	phone changing	spelling error
informal	40	4	3	3	5	8
formal	83	6	0	1	0	17

The recall metric is calculated for all FSTs as below

register / FST	standard	homophone	phone_change	expressive	splitter
informal	96.33%	96.42%	97.3%	97.3%	97.48%
formal	95.1%	95.1%	95.1%	95.1%	95.1%
combined (Contemporary)	95.56%	95.64%	96%	96%	96.08%

OOVs and OO-Rules

There is a list of words and inflections in OOs/extra.txt that are not included in Fsts. You can directly contribute to this list. This list will be used to update Fsts in a proper manner periodically. For contributing directly to this list, please use the following format, and for inflection, use the structure of this analyzer. Note that the third column (the context that the word appears in) is optional.

فونت[TAB]اسمعام=فونت+رسمی[TAB]فونت قشنگی استفاده کردن

Persian word structure; informal and formal

Comprehensive structure of words especially informal words are explained in the Contemporary Persian Inflectional Analyzer paper in full detail: docs/informal-analyzer.pdf; or from the Journal website

Citation

@article{Heidarpour2021, 
  title = {Contemporary Persian Inflectional Analyzer}, 
  author = {Heidarpour, Davood and S.Sebt, Elham and Bi Jen Khan, Mahmoud and Salehi, Mostafa and Veisi, Hadi },  
  volume = {36}, 
  number = {4},  
  URL = {http://jipm.irandoc.ac.ir/article-1-4337-en.html},  
  eprint = {http://jipm.irandoc.ac.ir/article-1-4337-en.pdf},  
  journal = {Iranian Journal of Information Processing and Management},   
  doi = {10.52547/jipm.36.4.945},  
  year = {2021}  
}

Fst word rule structure; informal and formal

All the lexicon, morphotactic and morphophonemic rules are in lexc folder. These files are used by a tool called Foma to compile Fsts. How the rules of words are developed to make Fsts are explained in Thesis: docs/thesis.pdf

Citation

@mastersthesis{Heidarpour2018,
  title = {An inflectional analyzer for contemporary Persian},
  author = {Heidarpour, Davood and Salehi, Mostafa and Bi Jen Khan, Mahmoud and Veisi, Hadi},
  year = {2018}
} 

Secondary Fsts

These Fsts are designed for covering out-of-vocabulary informal/noisy words and are explained in Covering Out-of-Vocabulary Words of Informal Persian paper: docs/informal-oov.pdf

Citation

@incollection{Heidarpour2019, 
  title = {Covering Out-of-Vocabulary Words of Informal Persian}, 
  author = {Heidarpour, Davood and Salehi, Mostafa and Bi Jen Khan, Mahmoud and Veisi, Hadi and Ranjbar, Vahid},  
  booktitle = {5th National Conference on Computational Linguistics},
  URL = {https://neveeseh.com},  
  year = {2019}  
}

License

Licensed under GNU General Public License Version 3 (GPLv3)