在python中对日期进行操作的库有：datetime、time
无论在哪种语言，日期函数肯定是最常用的函数。下面直接上实例代码
#datetimeimport datetime#当前日期now = datetime.datetime.now()print(now.strftime('%Y-%m-%d %H:%M:%S'))print(now.strftime('%Y-%m-%d'))#string convert to datetimetime_str = '2013-07-29 09:05:00'str_convert_2_time = datetime.datetime.strptime(time_str, '%Y-%m-%d %H:%M:%S')print(str_convert_2_time)#比较两个日期相差多少天time_strA = '2013-07-29 09:05:00'time_strB ='2013-08-29 09:05:00'day = datetime.datetime.strptime(time_strA, '%Y-%m-%d %H:%M:%S')day2 = datetime.datetime.strptime(time_strB, '%Y-%m-%d %H:%M:%S')sub_day = day2 - dayprint('{0}和{1}相差{2}天'.format(time_strA, time_strB, str(sub_day.days)))#今后的n天的日期n_days = 4now = datetime.datetime.now()my_date = datetime.timedelta(days=n_days) n_day = now + my_dateprint('从今天起的{0}天的日期是：'.format(n_days))print(n_day.strftime('%Y-%m-%d %H:%M:%S'))运行结果：
>>>
2013-07-29 09:48:16
2013-07-29
2013-07-29 09:05:00
2013-07-29 09:05:00和2013-08-29 09:05:00相差31天
从今天起的4天的日期是：
2013-08-02 09:48:16
>>>
