defdateRange(start,end,step=1,format="%Y-%m-%d"):strptime,strftime=datetime.datetime.strptime,datetime.datetime.strftimedays=(strptime(end,format)-strptime(start,format)).daysreturn[strftime(strptime(start,format)+datetime.timedelta(i),format)foriinxrange(0,days,step)]efweekend():try:dayday=dateRange(st,ed)fordayindayday:d=day.replace('-','')date=dserver_url="http://www.easybots.cn/api/holiday.php?d="vop_url_request=urllib2.Request(server_url+date)vop_response=urllib2.urlopen(vop_url_request)vop_data=json.loads(vop_response.read())ifvop_data[date]=='1'orvop_data[date]=='2':dayday.remove(day)returndaydayexcept:dayday=dateRange(st,ed)returndayday有这样一个weekend函数，去请求一些内容，但是每次执行出来会缺失一些内容怀疑是网速的问题，该怎么限制遍历时的频率或者几秒内访问一次呢？