new_contents: @bot.message_handler(commands=['calc'])
  def clac(m):
    userid = m.from_user.id
    banlist = redisserver.sismember('zigzag_banlist', '{}'.format(userid))
    if banlist:
      return
    if len(m.text.split()) < 2:
      bot.reply_to(m, "How can i calculate null?")
      return
    text = m.text.replace("/calc ","")
    res = urllib.urlopen("http://api.mathjs.org/v1/?expr={}".format(text).replace("+","%2B")).read()
    bot.send_message(m.chat.id, "_{}_ = `{}`".format(text,res), parse_mode="Markdown", disable_web_page_preview=True)
  
subject: Create calc.py