_list = ('会话数', '失效数', '连接数')

for index, c in enumerate(_list):
    try:
        res+="{}<span style='color: blue;'> ".format(c) + str(info[index + 1]).strip('\n')"</span><br>"
    except Exception,e:
        print e

Initialize info, for example info=[0,0,0] I think this is quite elegant!

JS implementation, similar to other languages.

res = '';
info.forEach(function(inf, i) {
  i === 1 && (res += '会话数' + inf);
  i === 2 && (res += '失效数' + inf);
  i === 3 && (res += '连接数' + inf);
});

Using the format function is a better choice than concatenating strings.

res += "{type}   {count}".format(type = ["会话数"， "失效数"， "连接数"][i],count = info[i])