pigLat.py

#! python
# ATBS Ch 6 - Pig Latin translator.
# Another string manipulation exercise from ATBS.
# English to Pig Latin
print('Enter the English message to translate into Pig Latin:')
message = input()

VOWELS = ('a', 'e', 'i', 'o', 'u', 'y')

pigLatin = [] # A list of the words in pig latin.

for word in message.split():
    # Separate the non-letters at the start of this word:
    prefixNonLetters = ''

    while len(word) > 0 and not word[0].isalpha():
        prefixNonLetters += word[0]
        word = word[1:]
    if len(word) == 0:
        pigLatin.append(prefixNonLetters)
        continue
    
    # Separate the non-letters at the end of this word:
    suffixNonLetters = ''
    while not word[-1].isalpha():
        suffixNonLetters += word[-1]
        word = word[:-1]
    wasUpper = word.isupper()
    wasTitle = word.istitle()
    word = word.lower() # Make the word lowercase for translation.
    # Separate the consonants at the start of this word:
    prefixConsonants = ''
    while len(word) > 0 and not word[0] in VOWELS:
        prefixConsonants += word[0]
        word = word[1:]
    # Add the Pig Latin ending to the word:
    if prefixConsonants != '':
        word += prefixConsonants + 'ay'
    else:
        word += 'yay'
    # Set the word back to uppercase or title case:
    if wasUpper:
        word = word.upper()
    if wasTitle:
        word = word.title()
    #Add the non-letters back to the start or end of the word.
    pigLatin.append(prefixNonLetters + word + suffixNonLetters)

# Join all the words back together in a single string:
print(' '.join(pigLatin))