统计文件中去重后的uuid个数

import re
pattern=re.compile(r'&uuid=.*&')
uuidset=set()
with open('request.log.2015-05-26','rt') as f:
        for line in f:
                all=pattern.findall(line)
                if len(all)>0 and line.find('iphone')>0:
                        # print(all[0])
                        uuidset.add(all[0])
print(len(uuidset))