python 日期大小比较

输入的日期跟当前日期比较大小 

日期在python中 存在time,datetime，string三种形式转化如下 

#str转time 

time.strptime('2018-09-28',"%Y-%m-%d")

#str转datetime

datetime.datetime.striptime('2018-09-28',"%Y-%m-%d")

#time 转string 

time.strftime("%y-%m-%d",time.localtime())

需求实现：

import datetime
import time
#将日期字符串转为时间再比较，time，datetime,str
def valid_date(timestr):
    #获取当前时间日期
    nowTime_str = datetime.datetime.now().strftime('%Y-%m-%d') 
    print(nowTime_str)
    #mktime参数为struc_time,将日期转化为秒，
    e_time = time.mktime(time.strptime(nowTime_str,"%Y-%m-%d"))
    print(e_time)
    try:
        s_time = time.mktime(time.strptime(timestr, '%Y-%m-%d'))
        print(s_time)
        #日期转化为int比较
        diff = int(s_time)-int(e_time)
        print(diff)
        if diff >= 0:
            return 1
        else:
            print('所查日期不能小于当前时间！！！')
            return 0
    except Exception as e:
        print(e)
        return 0
if __name__=='__main__':
    valid_date("2018-10-07")

执行结果：