nlp/count_syllables.py

import re
import string
from nltk.corpus import cmudict


cmu = cmudict.dict()


def count_syllables(word):
    lower_word = word.lower()
    if lower_word in cmu:
        return max([len([y for y in x if y[-1] in string.digits])
                    for x in cmu[lower_word]])
    else:
        return sylco(word)
 

 # by M. Emre Aydin from http://eayd.in/?p=232
def sylco(word) :
 
    word = word.lower()
 
    # exception_add are words that need extra syllables
    # exception_del are words that need less syllables
 
    exception_add = ['serious','crucial']
    exception_del = ['fortunately','unfortunately']
 
    co_one = ['cool','coach','coat','coal','count','coin','coarse','coup','coif','cook','coign','coiffe','coof','court']
    co_two = ['coapt','coed','coinci']
 
    pre_one = ['preach']
 
    syls = 0 #added syllable number
    disc = 0 #discarded syllable number
 
    #1) if letters < 3 : return 1
    if len(word) <= 3 :
        syls = 1
        return syls
 
    #2) if doesn't end with "ted" or "tes" or "ses" or "ied" or "ies", discard "es" and "ed" at the end.
    # if it has only 1 vowel or 1 set of consecutive vowels, discard. (like "speed", "fled" etc.)
 
    if word[-2:] == "es" or word[-2:] == "ed" :
        doubleAndtripple_1 = len(re.findall(r'[eaoui][eaoui]',word))
        if doubleAndtripple_1 > 1 or len(re.findall(r'[eaoui][^eaoui]',word)) > 1 :
            if word[-3:] == "ted" or word[-3:] == "tes" or word[-3:] == "ses" or word[-3:] == "ied" or word[-3:] == "ies" :
                pass
            else :
                disc+=1
 
    #3) discard trailing "e", except where ending is "le"  
 
    le_except = ['whole','mobile','pole','male','female','hale','pale','tale','sale','aisle','whale','while']
 
    if word[-1:] == "e" :
        if word[-2:] == "le" and word not in le_except :
            pass
 
        else :
            disc+=1
 
    #4) check if consecutive vowels exists, triplets or pairs, count them as one.
 
    doubleAndtripple = len(re.findall(r'[eaoui][eaoui]',word))
    tripple = len(re.findall(r'[eaoui][eaoui][eaoui]',word))
    disc+=doubleAndtripple + tripple
 
    #5) count remaining vowels in word.
    numVowels = len(re.findall(r'[eaoui]',word))
 
    #6) add one if starts with "mc"
    if word[:2] == "mc" :
        syls+=1
 
    #7) add one if ends with "y" but is not surrouned by vowel
    if word[-1:] == "y" and word[-2] not in "aeoui" :
        syls +=1
 
    #8) add one if "y" is surrounded by non-vowels and is not in the last word.
 
    for i,j in enumerate(word) :
        if j == "y" :
            if (i != 0) and (i != len(word)-1) :
                if word[i-1] not in "aeoui" and word[i+1] not in "aeoui" :
                    syls+=1
 
    #9) if starts with "tri-" or "bi-" and is followed by a vowel, add one.
 
    if word[:3] == "tri" and word[3] in "aeoui" :
        syls+=1
 
    if word[:2] == "bi" and word[2] in "aeoui" :
        syls+=1
 
    #10) if ends with "-ian", should be counted as two syllables, except for "-tian" and "-cian"
 
    if word[-3:] == "ian" : 
    #and (word[-4:] != "cian" or word[-4:] != "tian") :
        if word[-4:] == "cian" or word[-4:] == "tian" :
            pass
        else :
            syls+=1
 
    #11) if starts with "co-" and is followed by a vowel, check if exists in the double syllable dictionary, if not, check if in single dictionary and act accordingly.
 
    if word[:2] == "co" and word[2] in 'eaoui' :
 
        if word[:4] in co_two or word[:5] in co_two or word[:6] in co_two :
            syls+=1
        elif word[:4] in co_one or word[:5] in co_one or word[:6] in co_one :
            pass
        else :
            syls+=1
 
    #12) if starts with "pre-" and is followed by a vowel, check if exists in the double syllable dictionary, if not, check if in single dictionary and act accordingly.
 
    if word[:3] == "pre" and word[3] in 'eaoui' :
        if word[:6] in pre_one :
            pass
        else :
            syls+=1
 
    #13) check for "-n't" and cross match with dictionary to add syllable.
 
    negative = ["doesn't", "isn't", "shouldn't", "couldn't","wouldn't"]
 
    if word[-3:] == "n't" :
        if word in negative :
            syls+=1
        else :
            pass  
 
    #14) Handling the exceptional words.
 
    if word in exception_del :
        disc+=1
 
    if word in exception_add :
        syls+=1    
 
    # calculate the output
    return numVowels - disc + syls