Detecting syllables in a word

Question

Read about the TeX approach to this problem for the purposes of hyphenation. Especially see Frank Liang's thesis dissertation Word Hy-phen-a-tion by Com-put-er. His algorithm is very accurate, and then includes a small exceptions dictionary for cases where the algorithm does not work.

I stumbled across this page looking for the same thing, and found a few implementations of the Liang paper here: https://github.com/mnater/hyphenator or the successor: https://github.com/mnater/Hyphenopoly

That is unless you're the type that enjoys reading a 60 page thesis instead of adapting freely available code for non-unique problem. :)

Here is a solution using NLTK:

from nltk.corpus import cmudict
d = cmudict.dict()
def nsyl(word):
  return [len(list(y for y in x if y[-1].isdigit())) for x in d[word.lower()]] 

I'm trying to tackle this problem for a program that will calculate the flesch-kincaid and flesch reading score of a block of text. My algorithm uses what I found on this website: http://www.howmanysyllables.com/howtocountsyllables.html and it gets reasonably close. It still has trouble on complicated words like invisible and hyphenation, but I've found it gets in the ballpark for my purposes.

It has the upside of being easy to implement. I found the "es" can be either syllabic or not. It's a gamble, but I decided to remove the es in my algorithm.

private int CountSyllables(string word)
    {
        char[] vowels = { 'a', 'e', 'i', 'o', 'u', 'y' };
        string currentWord = word;
        int numVowels = 0;
        bool lastWasVowel = false;
        foreach (char wc in currentWord)
        {
            bool foundVowel = false;
            foreach (char v in vowels)
            {
                //don't count diphthongs
                if (v == wc && lastWasVowel)
                {
                    foundVowel = true;
                    lastWasVowel = true;
                    break;
                }
                else if (v == wc && !lastWasVowel)
                {
                    numVowels++;
                    foundVowel = true;
                    lastWasVowel = true;
                    break;
                }
            }

            //if full cycle and no vowel found, set lastWasVowel to false;
            if (!foundVowel)
                lastWasVowel = false;
        }
        //remove es, it's _usually? silent
        if (currentWord.Length > 2 && 
            currentWord.Substring(currentWord.Length - 2) == "es")
            numVowels--;
        // remove silent e
        else if (currentWord.Length > 1 &&
            currentWord.Substring(currentWord.Length - 1) == "e")
            numVowels--;

        return numVowels;
    }

This is a particularly difficult problem which is not completely solved by the LaTeX hyphenation algorithm. A good summary of some available methods and the challenges involved can be found in the paper Evaluating Automatic Syllabification Algorithms for English (Marchand, Adsett, and Damper 2007).

Why calculate it? Every online dictionary has this info. http://dictionary.reference.com/browse/invisible in·vis·i·ble

Bumping @Tihamer and @joe-basirico. Very useful function, not perfect, but good for most small-to-medium projects. Joe, I have re-written an implementation of your code in Python:

def countSyllables(word):
    vowels = "aeiouy"
    numVowels = 0
    lastWasVowel = False
    for wc in word:
        foundVowel = False
        for v in vowels:
            if v == wc:
                if not lastWasVowel: numVowels+=1   #don't count diphthongs
                foundVowel = lastWasVowel = True
                        break
        if not foundVowel:  #If full cycle and no vowel found, set lastWasVowel to false
            lastWasVowel = False
    if len(word) > 2 and word[-2:] == "es": #Remove es - it's "usually" silent (?)
        numVowels-=1
    elif len(word) > 1 and word[-1:] == "e":    #remove silent e
        numVowels-=1
    return numVowels

Hope someone finds this useful!