python中测试某一天属于哪一个星期模块

import arrow  # 时间模块，用来测试某一时间属于哪一个星期
from dateutil import tz
date='20180110'
arrow_time = arrow.get(date,"YYYYMMDD",tzinfo =tz.gettz("Asia/Shanghai"))
week = arrow_time.week
print('输出时间为第{}周'.format(week))