Pig Latin coding

You’re code seems to work for one word – you just need to call it for all words in the sentence:

def pig_latin(string):
  vowels = ['a', 'e', 'o', 'i', 'u']
  if string[0] in vowels:   #if the first letter is vowel 
      return string + 'ay' 
  elif string[1] in vowels: #if the first letter is consonant
      return string[1:] + string[0] + 'ay'
  elif string[2] in vowels: #if first two letters are consonants
      return string[2:] + string[:2] + 'ay'
  else: #if the first three letters are consonants
      return string[3:] + string[:3] + 'ay'

string = "the empire strikes back"
parts = string.split(" ")
pig_latin_parts = [pig_latin(part) for part in parts]
print(" ".join(pig_latin_parts)) // prints "ethay empireay ikesstray ackbay"