input: Write a function to generate a string from a list of phrases where each phrase is followed by its length in parentheses. The function should return the resulting string. If the input list is empty, the function should return an empty string.
  assert phrase_lengths(["A bird in the hand", "is worth two in the bush"]) == "A bird in the hand (17)is worth two in the bush (25)"
  assert phrase_lengths([]) == ""
  assert phrase_lengths(["Python", "is fun"]) == "Python (6)is fun (7)"
output: def phrase_lengths(phrases):
      if not phrases:
          return ""
      return ''.join(f"{phrase} ({len(phrase)})" for phrase in phrases)