import datetime

class Quriqi():
    """取区间日期模块，主要传入两个参数:
    Quriqi('20180601','20180608').suanriqi()  将会返回list类型 
    此类用的模块为datetime
    """

    def __init__(self,qishi,jiezhi):
        self.start = qishi
        self.end = jiezhi
        self.suanriqi()

    def suanriqi(self):
        datestart = datetime.datetime.strptime(self.start,'%Y%m%d')  
        dateend = datetime.datetime.strptime(self.end,'%Y%m%d')  
        riqi_list = [] 
        while datestart < dateend:
            datestart += datetime.timedelta(days=1)
            qu = datestart.strftime('%Y%m%d')
            riqi_list.append(qu)
        return riqi_list

a = Quriqi('20180518','20180520').suanriqi()
print(a)
# >>>['20180518','20180519','20180520'] # 打印结果