code: def for_sz(code):
      
  
      if str(code)[0:2] in ['00', '30', '02']:
          return 'stock_cn'
      elif str(code)[0:2] in ['39']:
          return 'index_cn'
      elif str(code)[0:2] in ['15']:
          return 'etf_cn'
      elif str(code)[0:2] in ['10', '11', '12', '13']:
          # 10xxxx 国债现货
          # 11xxxx 债券
          # 12xxxx 可转换债券
          # 12xxxx 国债回购
          return 'bond_cn'
  
      elif str(code)[0:2] in ['20']:
          return 'stockB_cn'
      else:
          return 'undefined'
docs: 深市代码分类
  
      Arguments:
          code {[type]} -- [description]
  
      Returns:
          [type] -- [description]