""" The original Metaphone algorithm was published in 1990 as an improvement over the Soundex algorithm. Like Soundex, it was limited to English-only use. The Metaphone algorithm does not produce phonetic representations of an input word or name; rather, the output is an intentionally approximate phonetic representation. The approximate encoding is necessary to account for the way speakers vary their pronunciations and misspell or otherwise vary words and names they are trying to spell. The Double Metaphone phonetic encoding algorithm is the second generation of the Metaphone algorithm. Its implementation was described in the June 2000 issue of C/C++ Users Journal. It makes a number of fundamental design improvements over the original Metaphone algorithm. It is called "Double" because it can return both a primary and a secondary code for a string; this accounts for some ambiguous cases as well as for multiple variants of surnames with common ancestry. For example, encoding the name "Smith" yields a primary code of SM0 and a secondary code of XMT, while the name "Schmidt" yields a primary code of XMT and a secondary code of SMT--both have XMT in common. Double Metaphone tries to account for myriad irregularities in English of Slavic, Germanic, Celtic, Greek, French, Italian, Spanish, Chinese, and other origin. Thus it uses a much more complex ruleset for coding than its predecessor; for example, it tests for approximately 100 different contexts of the use of the letter C alone. This script implements the Double Metaphone algorithm (c) 1998, 1999 originally implemented by Lawrence Philips in C++. It was further modified in C++ by Kevin Atkinson (http://aspell.net/metaphone/). It was translated to C by Maurice Aubrey for use in a Perl extension. A Python version was created by Andrew Collins on January 12, 2007, using the C source (http://www.atomodo.com/code/double-metaphone/metaphone.py/view). Updated 2007-02-14 - Found a typo in the 'gh' section (0.1.1) Updated 2007-12-17 - Bugs fixed in 'S', 'Z', and 'J' sections (0.2; Chris Leong) Updated 2009-03-05 - Various bug fixes against the reference C++ implementation (0.3; Matthew Somerville) Updated 2012-07 - Fixed long lines, added more docs, changed names, reformulated as objects, fixed a bug in 'G' (0.4; Duncan McGreggor) Updated 2013-06 - Enforced unicode literals (0.5; Ian Beaver) """ from __future__ import unicode_literals from ..utils import check_str, check_empty from .phonetic_algorithm import PhoneticAlgorithm VOWELS = ['A', 'E', 'I', 'O', 'U', 'Y'] SILENT_STARTERS = ["GN", "KN", "PN", "WR", "PS"] class DoubleMetaphone(PhoneticAlgorithm): def __init__(self): super().__init__() def phonetics(self, word : str) -> str | None: check_str(word) check_empty(word) st = word """dm(string) -> (string, string or None) returns the double metaphone codes for given string - always a tuple there are no checks done on the input string, but it should be a single word or name.""" vowels = ['A', 'E', 'I', 'O', 'U', 'Y'] #st = st.decode('utf-8', 'ignore') st = st.upper() # st is short for string. I usually prefer descriptive over short, but this var is used a lot! is_slavo_germanic = (st.find('W') > -1 or st.find('K') > -1 or st.find('CZ') > -1 or st.find('WITZ') > -1) length = len(st) first = 2 st = ('-') * first + st + (' ' * 5) # so we can index beyond the begining and end of the input string last = first + length -1 pos = first # pos is short for position pri = sec = '' # primary and secondary metaphone codes #skip these silent letters when at start of word if st[first:first+2] in ["GN", "KN", "PN", "WR", "PS"] : pos += 1 # Initial 'X' is pronounced 'Z' e.g. 'Xavier' if st[first] == 'X' : pri = sec = 'S' #'Z' maps to 'S' pos += 1 # main loop through chars in st while pos <= last : #print str(pos) + '\t' + st[pos] ch = st[pos] # ch is short for character # nxt (short for next characters in metaphone code) is set to a tuple of the next characters in # the primary and secondary codes and how many characters to move forward in the string. # the secondary code letter is given only when it is different than the primary. # This is just a trick to make the code easier to write and read. nxt = (None, 1) # default action is to add nothing and move to next char if ch in vowels : nxt = (None, 1) if pos == first : # all init vowels now map to 'A' nxt = ('A', 1) elif ch == 'B' : #"-mb", e.g", "dumb", already skipped over... see 'M' below if st[pos+1] == 'B' : nxt = ('P', 2) else : nxt = ('P', 1) elif ch == 'C' : # various germanic if (pos > (first + 1) and st[pos-2] not in vowels and st[pos-1:pos+2] == 'ACH' and \ (st[pos+2] not in ['I', 'E'] or st[pos-2:pos+4] in ['BACHER', 'MACHER'])) : nxt = ('K', 2) # special case 'CAESAR' elif pos == first and st[first:first+6] == 'CAESAR' : nxt = ('S', 2) elif st[pos:pos+4] == 'CHIA' : #italian 'chianti' nxt = ('K', 2) elif st[pos:pos+2] == 'CH' : # find 'michael' if pos > first and st[pos:pos+4] == 'CHAE' : nxt = ('K', 'X', 2) elif pos == first and (st[pos+1:pos+6] in ['HARAC', 'HARIS'] or \ st[pos+1:pos+4] in ["HOR", "HYM", "HIA", "HEM"]) and st[first:first+5] != 'CHORE' : nxt = ('K', 2) #germanic, greek, or otherwise 'ch' for 'kh' sound elif st[first:first+4] in ['VAN ', 'VON '] or st[first:first+3] == 'SCH' \ or st[pos-2:pos+4] in ["ORCHES", "ARCHIT", "ORCHID"] \ or st[pos+2] in ['T', 'S'] \ or ((st[pos-1] in ["A", "O", "U", "E"] or pos == first) \ and st[pos+2] in ["L", "R", "N", "M", "B", "H", "F", "V", "W", " "]) : nxt = ('K', 1) else : if pos > first : if st[first:first+2] == 'MC' : nxt = ('K', 2) else : nxt = ('X', 'K', 2) else : nxt = ('X', 2) #e.g, 'czerny' elif st[pos:pos+2] == 'CZ' and st[pos-2:pos+2] != 'WICZ' : nxt = ('S', 'X', 2) #e.g., 'focaccia' elif st[pos+1:pos+4] == 'CIA' : nxt = ('X', 3) #double 'C', but not if e.g. 'McClellan' elif st[pos:pos+2] == 'CC' and not (pos == (first +1) and st[first] == 'M') : #'bellocchio' but not 'bacchus' if st[pos+2] in ["I", "E", "H"] and st[pos+2:pos+4] != 'HU' : #'accident', 'accede' 'succeed' if (pos == (first +1) and st[first] == 'A') or \ st[pos-1:pos+4] in ['UCCEE', 'UCCES'] : nxt = ('KS', 3) #'bacci', 'bertucci', other italian else: nxt = ('X', 3) else : nxt = ('K', 2) elif st[pos:pos+2] in ["CK", "CG", "CQ"] : nxt = ('K', 'K', 2) elif st[pos:pos+2] in ["CI", "CE", "CY"] : #italian vs. english if st[pos:pos+3] in ["CIO", "CIE", "CIA"] : nxt = ('S', 'X', 2) else : nxt = ('S', 2) else : #name sent in 'mac caffrey', 'mac gregor if st[pos+1:pos+3] in [" C", " Q", " G"] : nxt = ('K', 3) else : if st[pos+1] in ["C", "K", "Q"] and st[pos+1:pos+3] not in ["CE", "CI"] : nxt = ('K', 2) else : # default for 'C' nxt = ('K', 1) elif ch == u'Ç' : nxt = ('S', 1) elif ch == 'D' : if st[pos:pos+2] == 'DG' : if st[pos+2] in ['I', 'E', 'Y'] : #e.g. 'edge' nxt = ('J', 3) else : nxt = ('TK', 2) elif st[pos:pos+2] in ['DT', 'DD'] : nxt = ('T', 2) else : nxt = ('T', 1) elif ch == 'F' : if st[pos+1] == 'F' : nxt = ('F', 2) else : nxt = ('F', 1) elif ch == 'G' : if st[pos+1] == 'H' : if pos > first and st[pos-1] not in vowels : nxt = ('K', 2) elif pos < (first + 3) : if pos == first : #'ghislane', ghiradelli if st[pos+2] == 'I' : nxt = ('J', 2) else : nxt = ('K', 2) #Parker's rule (with some further refinements) - e.g., 'hugh' elif (pos > (first + 1) and st[pos-2] in ['B', 'H', 'D'] ) \ or (pos > (first + 2) and st[pos-3] in ['B', 'H', 'D'] ) \ or (pos > (first + 3) and st[pos-4] in ['B', 'H'] ) : nxt = (None, 2) else : # e.g., 'laugh', 'McLaughlin', 'cough', 'gough', 'rough', 'tough' if pos > (first + 2) and st[pos-1] == 'U' \ and st[pos-3] in ["C", "G", "L", "R", "T"] : nxt = ('F', 2) else : if pos > first and st[pos-1] != 'I' : nxt = ('K', 2) elif st[pos+1] == 'N' : if pos == (first +1) and st[first] in vowels and not is_slavo_germanic : nxt = ('KN', 'N', 2) else : # not e.g. 'cagney' if st[pos+2:pos+4] != 'EY' and st[pos+1] != 'Y' and not is_slavo_germanic : nxt = ('N', 'KN', 2) else : nxt = ('KN', 2) # 'tagliaro' elif st[pos+1:pos+3] == 'LI' and not is_slavo_germanic : nxt = ('KL', 'L', 2) # -ges-,-gep-,-gel-, -gie- at beginning elif pos == first and (st[pos+1] == 'Y' \ or st[pos+1:pos+3] in ["ES", "EP", "EB", "EL", "EY", "IB", "IL", "IN", "IE", "EI", "ER"]) : nxt = ('K', 'J', 2) # -ger-, -gy- elif (st[pos+1:pos+2] == 'ER' or st[pos+1] == 'Y') \ and st[first:first+6] not in ["DANGER", "RANGER", "MANGER"] \ and st[pos-1] not in ['E', 'I'] and st[pos-1:pos+2] not in ['RGY', 'OGY'] : nxt = ('K', 'J', 2) # italian e.g, 'biaggi' elif st[pos+1] in ['E', 'I', 'Y'] or st[pos-1:pos+3] in ["AGGI", "OGGI"] : # obvious germanic if st[first:first+4] in ['VON ', 'VAN '] or st[first:first+3] == 'SCH' \ or st[pos+1:pos+3] == 'ET' : nxt = ('K', 2) else : # always soft if french ending if st[pos+1:pos+5] == 'IER ' : nxt = ('J', 2) else : nxt = ('J', 'K', 2) elif st[pos+1] == 'G' : nxt = ('K', 2) else : nxt = ('K', 1) elif ch == 'H' : # only keep if first & before vowel or btw. 2 vowels if (pos == first or st[pos-1] in vowels) and st[pos+1] in vowels : nxt = ('H', 2) else : # (also takes care of 'HH') nxt = (None, 1) elif ch == 'J' : # obvious spanish, 'jose', 'san jacinto' if st[pos:pos+4] == 'JOSE' or st[first:first+4] == 'SAN ' : if (pos == first and st[pos+4] == ' ') or st[first:first+4] == 'SAN ' : nxt = ('H',) else : nxt = ('J', 'H') elif pos == first and st[pos:pos+4] != 'JOSE' : nxt = ('J', 'A') # Yankelovich/Jankelowicz else : # spanish pron. of e.g. 'bajador' if st[pos-1] in vowels and not is_slavo_germanic \ and st[pos+1] in ['A', 'O'] : nxt = ('J', 'H') else : if pos == last : nxt = ('J', ' ') else : if st[pos+1] not in ["L", "T", "K", "S", "N", "M", "B", "Z"] \ and st[pos-1] not in ["S", "K", "L"] : nxt = ('J',) else : nxt = (None, ) if st[pos+1] == 'J' : nxt = nxt + (2,) else : nxt = nxt + (1,) elif ch == 'K' : if st[pos+1] == 'K' : nxt = ('K', 2) else : nxt = ('K', 1) elif ch == 'L' : if st[pos+1] == 'L' : # spanish e.g. 'cabrillo', 'gallegos' if (pos == (last - 2) and st[pos-1:pos+3] in ["ILLO", "ILLA", "ALLE"]) \ or ((st[last-1:last+1] in ["AS", "OS"] or st[last] in ["A", "O"]) \ and st[pos-1:pos+3] == 'ALLE') : nxt = ('L', '', 2) else : nxt = ('L', 2) else : nxt = ('L', 1) elif ch == 'M' : if st[pos+1:pos+4] == 'UMB' \ and (pos + 1 == last or st[pos+2:pos+4] == 'ER') \ or st[pos+1] == 'M' : nxt = ('M', 2) else : nxt = ('M', 1) elif ch == 'N' : if st[pos+1] == 'N' : nxt = ('N', 2) else : nxt = ('N', 1) elif ch == u'Ñ' : nxt = ('N', 1) elif ch == 'P' : if st[pos+1] == 'H' : nxt = ('F', 2) elif st[pos+1] in ['P', 'B'] : # also account for "campbell", "raspberry" nxt = ('P', 2) else : nxt = ('P', 1) elif ch == 'Q' : if st[pos+1] == 'Q' : nxt = ('K', 2) else : nxt = ('K', 1) elif ch == 'R' : # french e.g. 'rogier', but exclude 'hochmeier' if pos == last and not is_slavo_germanic \ and st[pos-2:pos] == 'IE' and st[pos-4:pos-2] not in ['ME', 'MA'] : nxt = ('', 'R') else : nxt = ('R',) if st[pos+1] == 'R' : nxt = nxt + (2,) else : nxt = nxt + (1,) elif ch == 'S' : # special cases 'island', 'isle', 'carlisle', 'carlysle' if st[pos-1:pos+2] in ['ISL', 'YSL'] : nxt = (None, 1) # special case 'sugar-' elif pos == first and st[first:first+5] == 'SUGAR' : nxt =('X', 'S', 1) elif st[pos:pos+2] == 'SH' : # germanic if st[pos+1:pos+5] in ["HEIM", "HOEK", "HOLM", "HOLZ"] : nxt = ('S', 2) else : nxt = ('X', 2) # italian & armenian elif st[pos:pos+3] in ["SIO", "SIA"] or st[pos:pos+4] == 'SIAN' : if not is_slavo_germanic : nxt = ('S', 'X', 3) else : nxt = ('S', 3) # german & anglicisations, e.g. 'smith' match 'schmidt', 'snider' match 'schneider' # also, -sz- in slavic language altho in hungarian it is pronounced 's' elif (pos == first and st[pos+1] in ["M", "N", "L", "W"]) or st[pos+1] == 'Z' : nxt = ('S', 'X') if st[pos+1] == 'Z' : nxt = nxt + (2,) else : nxt = nxt + (1,) elif st[pos:pos+2] == 'SC' : # Schlesinger's rule if st[pos+2] == 'H' : # dutch origin, e.g. 'school', 'schooner' if st[pos+3:pos+5] in ["OO", "ER", "EN", "UY", "ED", "EM"] : # 'schermerhorn', 'schenker' if st[pos+3:pos+5] in ['ER', 'EN'] : nxt = ('X', 'SK', 3) else : nxt = ('SK', 3) else : if pos == first and st[first+3] not in vowels and st[first+3] != 'W' : nxt = ('X', 'S', 3) else : nxt = ('X', 3) elif st[pos+2] in ['I', 'E', 'Y'] : nxt = ('S', 3) else : nxt = ('SK', 3) # french e.g. 'resnais', 'artois' elif pos == last and st[pos-2:pos] in ['AI', 'OI'] : nxt = ('', 'S', 1) else : nxt = ('S',) if st[pos+1] in ['S', 'Z'] : nxt = nxt + (2,) else : nxt = nxt + (1,) elif ch == 'T' : if st[pos:pos+4] == 'TION' : nxt = ('X', 3) elif st[pos:pos+3] in ['TIA', 'TCH'] : nxt = ('X', 3) elif st[pos:pos+2] == 'TH' or st[pos:pos+3] == 'TTH' : # special case 'thomas', 'thames' or germanic if st[pos+2:pos+4] in ['OM', 'AM'] or st[first:first+4] in ['VON ', 'VAN '] \ or st[first:first+3] == 'SCH' : nxt = ('T', 2) else : nxt = ('0', 'T', 2) elif st[pos+1] in ['T', 'D'] : nxt = ('T', 2) else : nxt = ('T', 1) elif ch == 'V' : if st[pos+1] == 'V' : nxt = ('F', 2) else : nxt = ('F', 1) elif ch == 'W' : # can also be in middle of word if st[pos:pos+2] == 'WR' : nxt = ('R', 2) elif pos == first and (st[pos+1] in vowels or st[pos:pos+2] == 'WH') : # Wasserman should match Vasserman if st[pos+1] in vowels : nxt = ('A', 'F', 1) else : nxt = ('A', 1) # Arnow should match Arnoff elif (pos == last and st[pos-1] in vowels) \ or st[pos-1:pos+5] in ["EWSKI", "EWSKY", "OWSKI", "OWSKY"] \ or st[first:first+3] == 'SCH' : nxt = ('', 'F', 1) # polish e.g. 'filipowicz' elif st[pos:pos+4] in ["WICZ", "WITZ"] : nxt = ('TS', 'FX', 4) else : # default is to skip it nxt = (None, 1) elif ch == 'X' : # french e.g. breaux nxt = (None,) if not(pos == last and (st[pos-3:pos] in ["IAU", "EAU"] \ or st[pos-2:pos] in ['AU', 'OU'])): nxt = ('KS',) if st[pos+1] in ['C', 'X'] : nxt = nxt + (2,) else : nxt = nxt + (1,) elif ch == 'Z' : # chinese pinyin e.g. 'zhao' if st[pos+1] == 'H' : nxt = ('J',) elif st[pos+1:pos+3] in ["ZO", "ZI", "ZA"] \ or (is_slavo_germanic and pos > first and st[pos-1] != 'T') : nxt = ('S', 'TS') else : nxt = ('S',) if st[pos+1] == 'Z' : nxt = nxt + (2,) else : nxt = nxt + (1,) # ---------------------------------- # --- end checking letters------ # ---------------------------------- #print str(nxt) if len(nxt) == 2 : if nxt[0] : pri += nxt[0] sec += nxt[0] pos += nxt[1] elif len(nxt) == 3 : if nxt[0] : pri += nxt[0] if nxt[1] : sec += nxt[1] pos += nxt[2] return pri, sec if pri != sec else None