docs: def get_tape(self, start=0, end=10):
          '''Pretty prints the tape values'''
          self.tape_start = start
          self.tape_end = end
          self.tape_length = end - start
          tmp = '\n'+"|"+str(start)+"|  "
          for i in xrange(len(self.tape[start:end])):
              if i == self.cur_cell:
                  tmp += "[" + str(self.tape[i]) + "] "
              else: tmp += ":" + str(self.tape[i]) + ": "
          tmp += " |"+str(end)+"|"
          return tmp