Python标准库笔记(3) — datetime模块

from datetime import date

print 'today():', date.today()  # 返回当前日期对象

print 'fromtimestamp(1491448600):', date.fromtimestamp(1491448600)  # 返回时间戳的日期对象

print 'date.fromordinal(1):', date.fromordinal(1)  # 返回对应公历序数的日期对象

# 输出
today():2017-04-06
fromtimestamp(1491448600):2017-04-06
date.fromordinal(1): 0001-01-01

from datetime import date

d = date(2017, 04, 06)

print 'd.year:', d.year    # 返回date对象的年份

print 'd.month:', d.month  # 返回date对象的月份

print 'd.day：', d.day     # 返回date对象的日

print 'd.timetuple():', d.timetuple()  # 返回date对象的struct_time结构

print 'd.toordinal():', d.toordinal()  # 返回公历日期的序数

print 'd.weekday():', d.weekday()      # 返回一星期中的第几天,星期一是0

print 'd.isoweekday():', d.isoweekday()  # 返回一星期中的第几天, 星期一1

print 'd.isocalendar():', d.isocalendar()  # 返回一个元组(年份, 这一年的第几周, 周几)

print 'd.isoformat():', d.isoformat()  # 以ISO 8601格式‘YYYY-MM-DD’返回date的字符串形式

print 'd.ctime():', d.ctime()  # 返回一个表示日期的字符串

print 'd.strftime("%Y-%m-%d"):', d.strftime("%Y-%m-%d")  # 返回指定格式的日期字符串

print 'd.replace(year=2012, month=12) :', d.replace(year=2012, month=12)  # 替换



# 输出

d.year: 2017
d.month: 4
d.day： 6
d.timetuple(): time.struct_time(tm_year=2017, tm_mon=4, tm_mday=6, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=3, tm_yday=96, tm_isdst=-1)
d.toordinal(): 736425
d.weekday(): 3
d.isoweekday(): 4
d.isocalendar(): (2017, 14, 4)
d.isoformat(): 2017-04-06
d.ctime(): Thu Apr  6 00:00:00 2017
d.strftime("%Y-%m-%d"): 2017-04-06
d.replace(year=2012, month=12) : 2012-12-06

from datetime import time

t = time(12, 10, 30, 50)

print 't.hour:', t.hour      # time对象小时数

print 't.minute:', t.minute  # time对象分钟数

print 't.second:', t.second  # time对象秒数

print 't.microsecond:', t.microsecond  # time对象微秒数

print 't.isoformat():', t.isoformat()  # 返回ISO 8601格式的时间字符串

print 't.strftime("%H:%M:%S:%f"):', t.strftime("%H:%M:%S:%f")  # 返回指定格式的时间格式

print 't.replace(hour=23, minute=0):', t.replace(hour=23, minute=0)  # 替换

# 输出

t.hour: 12
t.minute: 10
t.second: 30
t.microsecond: 50
t.isoformat(): 12:10:30.000050
t.strftime("%H:%M:%S:%f"): 12:10:30:000050
t.replace(hour=23, minute=0): 23:00:30.000050

from datetime import datetime, time, date

print 'datetime.today():', datetime.today()  # 返回本地当前的时间datetime对象

print 'datetime.now():', datetime.now()  # 返回本地当前的日期和时间的datetime对象

print 'datetime.utcnow():', datetime.utcnow()  # 返回当前UTC日期和时间的datetime对象

print 'datetime.fromtimestamp(1491468000):', datetime.fromtimestamp(1491468000)  # 返回对应时间戳的datetime对象

print 'datetime.fromordinal(699000):', datetime.fromordinal(699000)  # 同date.fromordinal类似

print 'datetime.combine(date(2012,12,12), time(12,12,12)):', datetime.combine(date(2012, 12, 12), time(23, 59, 59))  # 拼接date和time

print 'datetime.strptime("2012-12-10", "%Y-%m-%d"):', datetime.strptime("2012-12-10", "%Y-%m-%d")  # 将特定格式的日期时间字符串解析成datetime对象

# 输出
datetime.today(): 2017-04-06 16:53:12.080000
datetime.now(): 2017-04-06 16:53:12.080000
datetime.utcnow(): 2017-04-06 08:53:12.080000
datetime.fromtimestamp(1491468000): 2017-04-06 16:40:00
datetime.fromordinal(699000): 1914-10-19 00:00:00
datetime.combine(date(2012,12,12), time(12,12,12)): 2012-12-12 23:59:59
datetime.strptime("2012-12-10", "%Y-%m-%d"): 2012-12-10 00:00:00

from datetime import datetime
d = datetime(2017, 04, 06, 12, 10, 30)

print 'd.date():', d.date()  # 从datetime中拆分出date

print 'd.time():', d.time()  # 从datetime中拆分出time

print 'd.timetz()', d.timetz()  # 从datetime中拆分出具体时区属性的time

print 'd.replace(year=2016):', d.replace(year=2016)  # 替换

print 'd.timetuple():', d.timetuple()  # 时间数组,即struct_time结构

print 'd.toordinal():', d.toordinal()  # 和date.toordinal一样

print 'd.weekday():', d.weekday()      # 和date.weekday一样

print 'd.isoweekday():', d.isoweekday()  # 和date.isoweekday一样

print 'd.isocalendar():', d.isocalendar()  # 和date.isocalendar一样

print 'd.isoformat():', d.isoformat()  # 同上

print 'd.ctime():', d.ctime()  # 同上

print 'd.strftime("%Y/%m/%d %H:%M:%S"):', d.strftime('%Y/%m/%d %H:%M:%S')  # 同上

# 输出
d.date(): 2017-04-06
d.time(): 12:10:30
d.timetz() 12:10:30
d.replace(year=2016): 2016-04-06 12:10:30
d.timetuple(): time.struct_time(tm_year=2017, tm_mon=4, tm_mday=6, tm_hour=12, tm_min=10, tm_sec=30, tm_wday=3, tm_yday=96, tm_isdst=-1)
d.toordinal(): 736425
d.weekday(): 3
d.isoweekday(): 4
d.isocalendar(): (2017, 14, 4)
d.isoformat(): 2017-04-06T12:10:30
d.ctime(): Thu Apr  6 12:10:30 2017
d.strftime("%Y/%m/%d %H:%M:%S"): 2017/04/06 12:10:30

>>>from datetime import timedelta, date, datetime
>>>d = date.today()
>>>print d
2017-04-06
>>>print d - timedelta(days=5)  # 计算前5天
2017-04-01

>>>dt = datetime.now()
>>>print dt
2017-04-06 17:51:03.568000
>>>print dt - timedelta(days=1, hours=5)  # 计算前1天5小时
2017-04-05 12:51:03.568000

>>>from datetime import datetime
>>>timestamp = 1491550000
>>>dt = datetime.fromtimestamp(timestamp)
>>>print dt
2017-04-07 15:26:40
>>>print dt.strftime('%Y-%m-%d')
2017-04-07

>>>from datetime import datetime
>>>str = '2012-12-10'
>>>dt =datetime.strptime(str, '%Y-%m-%d')
>>>print dt.strftime('%Y/%m/%d')
>>>2012/12/10

>>>from datetime import datetime, timedelta
>>>td = datetime.today()
>>>print td
2017-04-07 16:27:52.111000
>>>print dt.strftime('%Y/%m/%d')
2017-04-06 16:27:52.111000