正则提取，替换re.sub，提取组里的值并+1
替换前的原文
content = "<i n='g't='m'v='1669399'/><i n='cdn't='c'v='1669472'/><i n='activity't='s'v='1682611'/>"
表达式
pattern = re.compile("n='cdn'.*?v='(\d+)'")
执行替换
result = re.sub(pattern, replace_num, content)
替换函数
def repace_versionnum(mc):
oldStr = mc.group(0) # 匹配出来的文本
oldV = mc.group(1) # 组提取的值
newV = str(int(oldV)+1) # +1
return oldStr.replace(oldV,newV)
替换后的文本，成功+1
<i n='g't='m'v='1669399'/><i n='cdn't='c'v='1669473'/><i n='activity't='s'v='1682611'/>