input: Write a python function to print the lengths of words in a list.
  assert word_lengths(["apple", "pie", "is", "delicious"])==[5, 3, 2, 9]
  assert word_lengths(["hello", "world"])==[5, 5]
  assert word_lengths(["python", "is", "fun"])==[6, 2, 3]
output: def word_lengths(words):
      return [len(word) for word in words]