code: def pad(num, n=2, sign=False):
      '''returns n digit string representation of the num'''
      s = unicode(abs(num))
      if len(s) < n:
          s = '0' * (n - len(s)) + s
      if not sign:
          return s
      if num >= 0:
          return '+' + s
      else:
          return '-' + f pad(num, n=2, sign=False):
      '''returns n digit string representation of the num'''
      s = unicode(abs(num))
      if len(s) < n:
          s = '0' * (n - len(s)) + s
      if not sign:
          return s
      if num >= 0:
          return '+' + s
      else:
          return '-' + s
docs: returns n digit string representation of the num