suggest.py

# -*- coding: utf-8 -*-
import re

from Levenshtein import ratio
from auxilia import (all_letters_greek, all_letters_latin,
                     some_letters_non_greek)
from words_backend import get_smlar_len_words

cleaner_dict = {
    u"τͅ": u'\u03c4',  # small tau
    u"δ́": u'\u03b4',  # delta
    u"ἴ́": u'\u03af',
    u"ἶͅ": u'\u03af',
    u"γ́": u'\u03b3',  # gamma
    u"κ̣": u'\u03ba',  # kappa
    u"ξ͂": u'\u03be',  # ksi
    u"ὸ́": u'\u03c3',
    u"κ̣": u'\u03ba',  # kappa
    u"τ̀ͅ": u'\u03c4',  # small tau
    u'ν̀': u'\u03bd',  # nu
    u'γ̣': u'\u03b3',  # gamma
    u'κ̓': u'\u03ba',  # kappa
    u"ί̣": u'\u03af',
    u"σ́": u'\u03c3',  # sigma
    u'ῦͅ': u"ῦ",
    u'κ̓': u'\u03ba',  # kappa
    u'τ͂': u'\u03c4',  # small tau
    u'κ́': u'\u03ba',  # kappa
}


def GREEK_ALPHABET():
    x = [u'\u0386', u'\u0388', u'\u0389', u'\u0390', u'\u0391', u'\u0392', \
         u'\u0393', u'\u0394', u'\u0395', u'\u0396', u'\u0397', u'\u0398', \
         u'\u0399', u'\u039a', u'\u039b', u'\u039c', u'\u039d', u'\u039e', \
         u'\u039f', u'\u03a0', u'\u03a1', u'\u03a3', u'\u03a4', u'\u03a5', \
         u'\u03a6', u'\u03a7', u'\u03a8', u'\u03a9', u'\u03ac', u'\u03ad', u'\u03ae', \
         u'\u03af', u'\u03b0', u'\u03b1', u'\u03b2', u'\u03b3', u'\u03b4', u'\u03b5', \
         u'\u03b6', u'\u03b7', u'\u03b8', u'\u03b9', u'\u03ba', u'\u03bb', u'\u03bc', \
         u'\u03bd', u'\u03be', u'\u03bf', u'\u03c0', u'\u03c1', u'\u03c2', u'\u03c3', \
         u'\u03c4', u'\u03c5', u'\u03c6', u'\u03c7', u'\u03c8', u'\u03c9', u'\u03ca', \
         u'\u03cb', u'\u03cc', u'\u03cd', u'\u03ce', u'\u1f00', u'\u1f01', u'\u1f02', \
         u'\u1f03', u'\u1f04', u'\u1f05', u'\u1f06', u'\u1f07', u'\u1f08', u'\u1f09', \
         u'\u1f0c', u'\u1f0e', u'\u1f10', u'\u1f11', u'\u1f13', u'\u1f14', u'\u1f15', \
         u'\u1f18', u'\u1f19', u'\u1f1d', u'\u1f20', u'\u1f21', u'\u1f22', u'\u1f23', \
         u'\u1f24', u'\u1f25', u'\u1f26', u'\u1f27', u'\u1f28', u'\u1f29', u'\u1f30', \
         u'\u1f31', u'\u1f33', u'\u1f34', u'\u1f35', u'\u1f36', u'\u1f37', u'\u1f38', \
         u'\u1f39', u'\u1f40', u'\u1f41', u'\u1f42', u'\u1f43', u'\u1f44', u'\u1f45', \
         u'\u1f48', u'\u1f4f', u'\u1f50', u'\u1f51', u'\u1f53', u'\u1f54', u'\u1f55', \
         u'\u1f56', u'\u1f57', u'\u1f59', u'\u1f60', u'\u1f61', u'\u1f62', u'\u1f63', \
         u'\u1f64', u'\u1f65', u'\u1f66', u'\u1f67', u'\u1f68', u'\u1f70', u'\u1f71', \
         u'\u1f72', u'\u1f73', u'\u1f74', u'\u1f75', u'\u1f76', u'\u1f77', u'\u1f78', \
         u'\u1f79', u'\u1f7a', u'\u1f7b', u'\u1f7c', u'\u1f7d', u'\u1f84', u'\u1f85', \
         u'\u1f86', u'\u1f90', u'\u1f91', u'\u1f94', u'\u1f96', u'\u1f97', u'\u1fa0', \
         u'\u1fa4', u'\u1fa6', u'\u1fa7', u'\u1fb3', u'\u1fb4', u'\u1fb6', u'\u1fb7', \
         u'\u1fbd', u'\u1fbf', u'\u1fc2', u'\u1fc3', u'\u1fc4', u'\u1fc6', u'\u1fc7', \
         u'\u1fd2', u'\u1fd3', u'\u1fd6', u'\u1fe2', u'\u1fe3', u'\u1fe4', u'\u1fe5', \
         u'\u1fe6', u'\u1fec', u'\u1ff3', u'\u1ff4', u'\u1ff6', u'\u1ff7', u'\u2018', \
         u'\u2019', u'\u2219']
    return x


def smart_suggest(incorrect):
    """
    Called smart suggest because the prev version 
    was really dummy.
    :param incorrect str
    :return dict with suggested correct words
    :rtype dict
    """
    suggestions = []
    if all_letters_greek(incorrect):
        suggestions = get_similar_by_levens(incorrect)
    if all_letters_latin(incorrect):
        suggestions = translate_latin_chars(incorrect)
    if some_letters_non_greek(incorrect):
        suggestions = find_by_re_substitution(incorrect)
    return {w: w for w in suggestions}


def find_by_re_substitution(incorr):
    """
    incorr is a greek word that possibly has only one letter
    mis-ocred, so replace it with dot and run re match
    """
    GREEK_ALP = range(900, 988)
    for letter in incorr:
        if ord(letter) not in GREEK_ALP:
            pattern = incorr.replace(letter, '.')
    pat = re.compile(pattern)
    WORDS = get_smlar_len_words(incorr)
    suggestions = [w for w in WORDS if \
                   re.match(incorr, w) is not None]
    return suggestions


def get_similar_by_levens(incorrect):
    """Take all words of similar distance
    and return five most similar as measured
    by Levenstein distance"""
    vals = {}
    WORDS = get_smlar_len_words(incorrect)
    for correct in WORDS:
        similarity_ratio = ratio(incorrect, correct)
        if similarity_ratio > 0.65:
            vals[correct] = similarity_ratio
    all_suggestions = sorted([c for c, v in vals.items()], key=lambda v: v)
    return all_suggestions[:5]


def translate_latin_chars(incorrect):
    """
    Given most common mistakes OCR makes
    try to translate mistaken latin chars
    to their most likely greek origins
    :param incorrect: 
    :return: 
    """
    diphthongs = {u'rj': u'\u1f21',  # eta
                  u'qp': u'\u03c6',  # hhi
                  u'ft': u'\u03bc',  # mi
                  u'fi': u'\u03b2',  # beta
                  }
    dykt = {
        'a': 'α',  # u'\u03b1',  # alpha
        # u'b':,
        # 'c':,
        'd': 'δ',  # u'\u03b4',  # delta
        'e': 'ε',  # u'\u03b5',  # epsilon
        # 'f': '' #,
        'g': 'ς',  # u'\u03c2',  # final sigma
        # 'h':,
        'i': 'ι',  # u'\u03b9',  # iota
        # 'j':,
        # 'k':,
        # 'l':,
        # 'm':,
        'n': 'π',  # u'\u03c0',  # pi
        'o': 'σ',  # u'\u03c3',  # sigma or omikron
        # 'p':,
        'q': 'ρ',  # u'\u03c1',  # rho
        'r': 'η',  # u'\u03b7',  # eta
        # u's':,
        't': 'ι',  # u'\u03b9',
        'u': 'α',  # u'\u03b1',  # alpha,
        'v': 'ν',  # u'\u03bd',  # nu
        'w': 'ω',  # u'\u03c9',  # omega
        'x': 'κ',  # u'\u03ba',  # kappa
        'y': 'γ',  # u'\u03b3',  # gamma
        # 'z':,
        # 'A':,
        # 'B':,
        # 'C':,
        # 'D':,
        # 'E':,
        # 'F':,
        # 'G':,
        # 'H':,
        # 'I':,
        # 'J':,
        # 'K':,
        'L': 'ί',  # u'\u03af',  # iota with acutus
        # 'M':,
        # 'N':,
        # 'O':,
        # 'P':,
        'Q': 'ρ',  # u'\u03c1',  # rho
        # 'R':,
        'S': 'δ',  # u'\u03b4',  # delta
        'T': 'τ',  # u'\u03c4',  # small tau
        # 'U':,
        # 'V':,
        # 'W':,
        'X': 'λ',  # u'\u03bb',  # small lambda
        # 'Y':,
        # 'Z':,
        '\\': '',  # u'\u1f76',  # iota with gravis
        '&': 'θ',  # u'\u03b8',  # theta
        '§': 'ξ',  # u'\u03be',  # ksi
        '6': 'δ',  # u'\u03b4',  # delta
        'ŕ': 'ή',  # u'\u03ae',  # eta z acutusem

    }
    for d in diphthongs.keys():
        incorrect = incorrect.replace(d, diphthongs[d])
    greek_word = ""
    for latin_char in incorrect:
        greek_word += dykt.get(latin_char, latin_char)
    return greek_word