python从字符串中提取指定的内容

有如下字符串：

text=cssPath:"http://imgcache.qq.com/ptlogin/v4/style/32",sig:"OvL7F1OQEojtPkn5x2xdj1*uYPm*H3mpaOf3rs2M",clientip:"82ee3af631dd6ffe",serverip:"",version:"201404010930"

怎么提取元素为sig的值？就是OvL7F1OQEojtPkn5x2xdj1*uYPm*H3mpaOf3rs2M

 import re

 s = 'text=cssPath:"http://imgcache.qq.com/ptlogin/v4/style/32",sig:"OvL7F1OQEojtPkn5x2xdj1*uYPm*H3mpaOf3rs2M",clientip:"82ee3af631dd6ffe",serverip:"",version:"201404010930"'

 res = re.findall(r'sig:"([^"]+)"',s)
 print(res)
 print(res[0])

运行结果如下：

['OvL7F1OQEojtPkn5x2xdj1*uYPm*H3mpaOf3rs2M']
OvL7F1OQEojtPkn5x2xdj1*uYPm*H3mpaOf3rs2M