If the goal of the elif block where your error is occurring is to put the variable cmd into a list of characters. Then set ansnum = 0 rather than ansnum = 4

Could you explain what

  elif "ans" in cmd:
    ansnum = 4
    answer = list()
    for i in range(len(cmd)):
      print(i)
      answer.append(cmd[ansnum])
      ansnum += 1
    print(answer)

does?