Turns a phrase into pig latin following the rules described on https://en.wikipedia.org/wiki/Pig_Latin

pig_latin.py

# simple check for if something is a "vowel"
def isVowel(letter):
    return letter in ["a","e","i","o","u","y"]

# only phrases that contain only alpha characters is accepted
valid = False
while not valid:
    phrase = raw_input("Enter a phrase ==> ")
    valid = phrase.replace(" ","").isalpha()

# separate it out to handle each word
words = phrase.split()

for i in range(len(words)):
    word = words[i]
    
    # special case for words that start with vowels (y doesn't count here)
    if isVowel(word[0]) and word[0] != 'y':
        word += "-ay"
    else:
        j = 1;
        while j < len(word):
            if isVowel(word[j]):
                break
            j += 1
        word = word[j:]+"-"+word[:(j)]+"ay"

    # make sure new word has the same first letter capitalization as old word
    if word[word.index('-')+1].isupper():
        word = word.lower().capitalize()
    else:
        word = word.lower()
    
    words[i] = word

# .join() applies the string between all elements of the list. Easier than a for loop.
pig_latin = ' '.join(words)

print pig_latin