old_contents: # 6.22
  
  
  def get_mnemonics(ph_num, mapping):
      pass
  
  
  def test():
      pass
  
new_contents: # 6.22
  mapping = {
      2: ["a", "b", "c"],
      3: ["d", "e", "f"],
      4: ["g", "h", "i"],
      5: ["j", "k", "l"],
      6: ["m", "n", "o"],
      7: ["p", "q", "r", "s"],
      8: ["t", "u", "v"],
      9: ["w", "x", "y", "z"]
  }
  
  
  def get_mnemonics_recursive(ph_num, mnemonic):
      if len(ph_num) == 0:
          print mnemonic
          return
      digit = ph_num[0]
      for letter in mapping[digit]:
          m = mnemonic + letter
          get_mnemonics_recursive(ph_num[1:], m)
  
  
  def test():
      ph_num = [2, 3, 2]
      get_mnemonics_recursive(ph_num, "")
  
subject: Update phone_number_mnemonic.py