code: def convert(number, fromdigits, todigits):
      # Based on http://code.activestate.com/recipes/111286/
      if str(number)[0] == "-":
          number = str(number)[1:]
          neg = 1
      else:
          neg = 0
  
      # make an integer out of the number
      x = 0
      for digit in str(number):
          x = x * len(fromdigits) + fromdigits.index(digit)
  
      # create the result in base 'len(todigits)'
      if x == 0:
          res = todigits[0]
      else:
          res = ""
          while x > 0:
              digit = x % len(todigits)
              res = todigits[digit] + res
              x = int(x / len(todigits))
          if neg:
              res = "-" + res
      return res
  
label_desc: Use image node_id 4 for calling the BaseConverter obj's underlying member method code with example usage: obj.convert(number, fromdigits, todigits) and returns: res