import datetime

 import time

 DATETIME_FORMAT = "%Y-%m-%d  %H:%M:%S"

 DATE_FORMAT = "%Y-%m-%d"

 def get_now_timestamp_13():

     return int(time.time()*1000)

 def get_now_date():

     return time.strftime(DATE_FORMAT)

 # 使用datetime.date.today()返回的类型是datetime类型，需要将它变为字符串型

 def get_yesterday():

     today = datetime.date.today()

     return str(today - datetime.timedelta(days=1))

 def get_now_datetime():

     return time.strftime(DATETIME_FORMAT)

 def timestamp_to_datetime(timestamp):

     # 时间戳转日期时间格式  都是先转为一个下面一样的tuple，再通过strftime(format，tuple)转为datetime，通过strptime(datetime，format)转为时间戳

     # time.struct_time(tm_year=2017, tm_mon=12, tm_mday=20, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=2, tm_yday=354,tm_isdst=-1)

     return time.strftime(DATETIME_FORMAT,time.localtime(timestamp/1000))

 def datetime_to_timestamp_13(datetime):

     return int(time.mktime(time.strptime(datetime,DATETIME_FORMAT))*1000)

 def datetime_to_timestamp_10(datetime):

     return int(time.mktime(time.strptime(datetime,DATETIME_FORMAT)))

 if __name__ == '__main__':

     # print(time.localtime())

     # print(time.strptime("2017-12-20","%Y-%m-%d"))

     # print(time.mktime(time.strptime("2017-12-20","%Y-%m-%d")))

     # print(time.localtime(1513699200))

     # print(1513699210789/1000)

     # print(time.strftime("%Y-%m-%d %H-%M-%S",time.localtime(1513699210789/1000)))

     # print(timestamp_to_datetime(get_now_timestamp_13()))

     # print(datetime_to_timestamp(timestamp_to_datetime(get_now_timestamp_13())))

     # print(get_now_timestamp_13())

     print(get_now_date())

     print(get_now_datetime())