import datetime


def date_week(date):
    '''
    功能：获取日期对应的周数（一年算52周，超过一年的范围，相同周数按照年区分）
        week=00时周数算去年最后一周
        判断 date 类型来分别做处理（字符串日期和日期类型）
    :param date: 字符串日期，strptime方法 格式化规则
    :return: 返回值，日期对应周数
    '''
    week = ''
    if isinstance(date, str):
        week = datetime.datetime.strptime(date, '%Y%m%d').strftime('%W')
        if week == '00':
            year = datetime.datetime.strptime(date, '%Y%m%d').year - 1
            week = str(year) + '-52'
        else:
            week = datetime.datetime.strptime(date, '%Y%m%d').strftime('%Y-%W')
    elif isinstance(date, datetime.datetime):
        week = date.strftime('%W')
        if week == '00':
            year = date.year - 1
            week = str(year) + '-52'
        else:
            week = date.strftime('%Y-%W')
    else:
        raise ValueError('{} 需要包含（年月日），字符串日期或者日期格式'.format(date))
    return week