Python 中处理时间的模块有三个，datetime 、time 、calendar 融汇贯通这三个模块，才能随心所欲地用 python 处理日期和时间。

模块分类

datetime

  • 获取当前日期时间（datetime 类型）
>>> import datetime

>>> now = datetime.datetime.now()
或：
>>> now = datetime.datetime.today()
>>> now
datetime.datetime(2018, 7, 26, 22, 37, 0, 511448)
>>> type(now)
<class 'datetime.datetime'>
  • 获取当前日期（date 类型）
>>> date = datetime.datetime.now().date()
>>> date
datetime.date(2018, 7, 26)
>>> type(date)
<class 'datetime.date'>
  • 获取当前时间（time 类型）
>>> time = datetime.datetime.now().time()
>>> time
datetime.time(22, 40, 50, 222226)
>>> type(time)
<class 'datetime.time'>

time

  • 获取当前时间的时间戳
>>> import time

>>> time.time()
1532615540.215679
  • 获取本地时间
>>> time.localtime(time.time())
time.struct_time(tm_year=2018, tm_mon=7, tm_mday=26, tm_hour=22, tm_min=33, tm_sec=26, tm_wday=3, tm_yday=207, tm_isdst=0)
  • 获取格式化时间
>>> time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()) 
'2018-07-26 22:34:23'

calendar

  • 获取年历
>>> import calendar
>>> calendar.calendar(2018)
  • 获取月历
>>> calendar.month(2018, 7)
  • 获取日期为星期几（0-6 代表星期一到星期日）
>>> calendar.weekday(2017, 7, 30)
6

日期和时间计算

日期计算

  • 获取明天
>>> import datetime

>>> tomorrow = datetime.datetime.now() + datetime.timedelta(days=1)
>>> tomorrow
datetime.datetime(2018, 7, 27, 22, 45, 51, 503706)
  • 获取昨天
>>> yesterday = datetime.datetime.now() - datetime.timedelta(days=1)
>>> yesterday
datetime.datetime(2018, 7, 25, 22, 46, 21, 865430)
  • 获取本月第一天
>>> now = datetime.datetime.now()
>>> datetime.date(now.year, now.month, 1)
datetime.date(2018, 7, 1)
  • 获取本月最后一天
>>> import calendar

>>> now = datetime.datetime.now()
>>> first_day_weekday, last_day_num = calendar.monthrange(now.year, now.month)
>>> datetime.date(now.year, now.month, last_day_num)
datetime.date(2018, 7, 31)

时间计算

  • 获取一小时前
>>> import datetime

>>> datetime.datetime.now() - datetime.timedelta(hours=1)
datetime.datetime(2018, 7, 26, 21, 47, 28, 970671)
  • 获取当天最小时间
>>> datetime.datetime.combine(datetime.date.today(), datetime.time.min)
datetime.datetime(2018, 7, 26, 0, 0)

格式转换

格式转换

datetime <=> date

  • datetime => date
>>> datetime.datetime.now().date()
datetime.date(2018, 7, 26)
  • date => datetime
>>> today = datetime.date.today()
>>> datetime.datetime.combine(today, datetime.time.min)
datetime.datetime(2018, 7, 26, 0, 0)

datetime <=> timestamp

  • datetime => timestamp
>>> import time 

>>> time.mktime(datetime.datetime.now().timetuple())
1532617383.0
  • timestamp => datetime
>>> datetime.datetime.fromtimestamp(1532617383.0)
datetime.datetime(2018, 7, 26, 23, 3, 3)

datetime <=> string

  • datetime => string
>>> datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
'2018-07-26 23:04:41'
  • string => datetime
>>> datetime.datetime.strptime("2010-01-20 17:30:15", "%Y-%m-%d %H:%M:%S")
datetime.datetime(2010, 1, 20, 17, 30, 15)

datetime <=> timetuple

  • datetime => timetuple
>>> datetime.datetime.now().timetuple()
time.struct_time(tm_year=2018, tm_mon=7, tm_mday=26, tm_hour=23, tm_min=6, tm_sec=1, tm_wday=3, tm_yday=207, tm_isdst=-1)
>>> datetime.datetime.now().timetuple().tm_year
2018
  • timetuple => datetime
>>> time_tuple = datetime.datetime.now().timetuple()
>>> datetime.datetime.fromtimestamp(time.mktime(time_tuple))
datetime.datetime(2018, 7, 26, 23, 6, 40)

日期和时间格式化(符号)

strftime(format[, tuple]) -> string
将指定的struct_time(默认为当前时间)，根据指定的格式化字符串输出。

序号 字符 描述
1 %Y 四位数的年份
2 %m 月份 [01-12]
3 %d 天 [0-31]
4 %H 小时(24小时制) [0-23]
5 %I 小时(12小时制 [01-12]
6 %M 分钟 [00-59]
7 %S 秒 [00-59] 
>>> import datetime
>>> datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
'2018-07-26 23:17:32'

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