如何计算定时事件下次执行前的时间增量

使用 dateutil ( ):

import datetime
import random
import dateutil.relativedelta as dr
import itertools

day_of_week = [1,3,5,6]
hour = [1,10,15,17,20]
minute = [4,34,51,58]

now=datetime.datetime.now()
deltas=[]

for min,hr,dow in itertools.product(minute,hour,day_of_week):
    # dateutil convention: Monday = 0, Sunday = 6.
    next_dt=now+dr.relativedelta(minute=min,hour=hr,weekday=dow)
    delta=next_dt-now
    deltas.append(delta)

deltas.sort()

这是下一次Delta:

print(deltas[0])
# 4 days, 14:22:00

下面是相应的日期时间:

print(now+deltas[0])
# 2010-09-02 01:04:23.258204

注意,dateutil使用约定Monday=0,Sunday=6。

以防有人感兴趣,这是我用~unutbu建议开发的代码。它的主要优点是伸缩性好。

import datetime
import dateutil.relativedelta as dr

def next_ocurrance(minutes, hours, days_of_week):
    # days_of_week convention: Sunday = 0, Saturday = 6
    # dateutil convention: Monday = 0, Sunday = 6

    now = datetime.datetime.now()
    weekday = now.isoweekday()
    execute_this_hour = weekday in days_of_week \
                        and now.hour in hours \
                        and now.minute < max(minutes)

    if execute_this_hour:
        next_minute = min([minute for minute in minutes
                           if minute > now.minute])
        return now + dr.relativedelta(minute=next_minute,
                                      second=0,
                                      microsecond=0)
    else:
        next_minute = min(minutes)

    execute_today = weekday in day_of_week \
                    and (now.hour < max(hours) or execute_this_hour)

    if execute_today:
        next_hour = min([hour for hour in hours if hour > now.hour])
        return now + dr.relativedelta(hour=next_hour,
                                      minute=next_minute,
                                      second=0,
                                      microsecond=0)
    else:
        next_hour = min(hours)
        next_day = min([day for day in days_of_week if day > weekday] \
                       or days_of_week)

        return now + dr.relativedelta(weekday=(next_day - 1) % 7,
                                      hour=next_hour,
                                      minute=next_minute,
                                      second=0,
                                      microsecond=0)
if __name__=='__main__':
    day_of_week = [4]
    hour = [1, 10, 12, 13]
    minute = [4, 14, 34, 51, 58]
    print next_ocurrance(minute, hour, day_of_week)