第三方库 --datetime库
f==format p==parse
1、获取当前时间（日期格式）
from datetime import datetime datetime.now()
#输出 datetime.datetime(2019, 9, 12, 20, 17, 15, 426867)
2、由日期格式转化为字符串格式的函数为: datetime.datetime.strftime()
datetime.now().strftime('%b-%m-%y %H:%M:%S')
#输出'Sep-09-19 20:12:56'
3、由字符串格式转化为日期格式的函数为: datetime.datetime.strptime()
datetime.strptime('Sep-09-19 20:12:56','%b-%d-%y %H:%M:%S')
#输出为： datetime.datetime(2019, 9, 9, 20, 12, 56)
4、两个函数都涉及日期时间的格式化字符串，列举如下：
%a 星期几的简写;如 星期三为Web
%A 星期几的全称;如 星期三为Wednesday
%b 月份的简写; 如4月份为Apr
%B 月份的全称; 如4月份为April
%c 标准的日期的时间串;（如： 04/07/10 10:43:39）
%C 年份的后两位数字
%d 十进制表示的每月的第几天
%D 月/天/年
%e 在两字符域中，十进制表示的每月的第几天
%F 年-月-日
%g 年份的后两位数字，使用基于周的年
%G 年分，使用基于周的年
%h 简写的月份名
%H 24小时制的小时
%I 12小时制的小时
%j 十进制表示的每年的第几天
%m 十进制表示的月份
%M 十时制表示的分钟数
%n 新行符
%p 本地的AM或PM的等价显示
%r 12小时的时间
%R 显示小时和分钟：hh:mm
%S 十进制的秒数
%t 水平制表符
%T 显示时分秒：hh:mm:ss
%u 每周的第几天，星期一为第一天 （值从0到6，星期一为0）
%U 第年的第几周，把星期日做为第一天（值从0到53）
%V 每年的第几周，使用基于周的年
%w 十进制表示的星期几（值从0到6，星期天为0）
%W 每年的第几周，把星期一做为第一天（值从0到53）
%x 标准的日期串
%X 标准的时间串
%y 不带世纪的十进制年份（值从0到99）
%Y 带世纪部分的十制年份
%z，%Z 时区名称，如果不能得到时区名称则返回空字符。
%% 百分号
import datetime
import time
1、string格式转换成datetime格式
string = '2019-09-12'
date_time = datetime.datetime.strptime(string,'%Y-%m-%d')
2、datetime格式转换成String格式
string = date_time.strftime('%Y-%m-%d')
3、datetime转换为时间戳
time_stamp = time.mktime(date_time.timetuple())
4、时间戳转换成string
string = time.strftime('%Y-%m-%d',time.localtime(time_stamp))
一个timedelta对象表示一个时间长度，两个日期或者时间的差值
class datetime.timedelta(days=0,seconds=0,microseconds=0,milliseconds=0,minutes=0,hours=0,weeks=0)
所有的参数都是可选的，默认值为0，参数可以是整数或者浮点数，既可以是整数也可以是负数。
虽然说参数可以传递的单位很多，但是python内部实现只存储了days，seconds和microseconds三种单位，所有其他的单位在计算时都会转换成相应的三种单位：
1 millisecond = 1000 microseconds
1 minute = 60 seconds
1 hour = 3600 seconds
1 week = 7 days
一、两个datetime.datetime类型相减或者两个datetime.date类型相减的结果就是daftetime.delta类型
二、以下是具体使用方法
1、以下是打印未来一天后的时间
def next_day(date_str): date = datetime.datetime.strptime(date_str, "%Y-%m-%d") date = date + datetime.timedelta(days=1) return date.strftime("%Y-%m-%d")
2、以下是打印一天前的时间
def prev_day(date_str): date = datetime.datetime.strptime(date_str, "%Y-%m-%d") date = date - datetime.timedelta(days=1) return date.strftime("%Y-%m-%d")
同理，其他时间单位也是一样的
以下是原文说明
CLASSES
builtins.object
date
datetime
time
timedelta
tzinfo
timezone
class date(builtins.object)
| date(year, month, day) --> date object
|
| Methods defined here:
|
| __add__(self, value, /)
| Return self+value.
|
| __eq__(self, value, /)
| Return self==value.
|
| __format__(...)
| Formats self with strftime.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __lt__(self, value, /)
| Return self<value.
|
| __ne__(self, value, /)
| Return self!=value.
|
| __radd__(self, value, /)
| Return value+self.
|
| __reduce__(...)
| __reduce__() -> (cls, state)
|
| __repr__(self, /)
| Return repr(self).
|
| __rsub__(self, value, /)
| Return value-self.
|
| __str__(self, /)
| Return str(self).
|
| __sub__(self, value, /)
| Return self-value.
|
| ctime(...)
| Return ctime() style string.
|
| isocalendar(...)
| Return a 3-tuple containing ISO year, week number, and weekday.
|
| isoformat(...)
| Return string in ISO 8601 format, YYYY-MM-DD.
|
| isoweekday(...)
| Return the day of the week represented by the date.
| Monday == 1 ... Sunday == 7
|
| replace(...)
| Return date with new specified fields.
|
| strftime(...)
| format -> strftime() style string.
|
| timetuple(...)
| Return time tuple, compatible with time.localtime().
|
| toordinal(...)
| Return proleptic Gregorian ordinal. January 1 of year 1 is day 1.
|
| weekday(...)
| Return the day of the week represented by the date.
| Monday == 0 ... Sunday == 6
|
| ----------------------------------------------------------------------
| Class methods defined here:
|
| fromisocalendar(...) from builtins.type
| int, int, int -> Construct a date from the ISO year, week number and weekday.
|
| This is the inverse of the date.isocalendar() function
|
| fromisoformat(...) from builtins.type
| str -> Construct a date from the output of date.isoformat()
|
| fromordinal(...) from builtins.type
| int -> date corresponding to a proleptic Gregorian ordinal.
|
| fromtimestamp(timestamp, /) from builtins.type
| Create a date from a POSIX timestamp.
|
| The timestamp is a number, e.g. created via time.time(), that is interpreted
| as local time.
|
| today(...) from builtins.type
| Current date or datetime: same as self.__class__.fromtimestamp(time.time()).
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| day
|
| month
|
| year
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| max = datetime.date(9999, 12, 31)
|
| min = datetime.date(1, 1, 1)
|
| resolution = datetime.timedelta(days=1)
class datetime(date)
| datetime(year, month, day[, hour[, minute[, second[, microsecond[,tzinfo]]]]])
|
| The year, month and day arguments are required. tzinfo may be None, or an
| instance of a tzinfo subclass. The remaining arguments may be ints.
|
| Method resolution order:
| datetime
| date
| builtins.object
|
| Methods defined here:
|
| __add__(self, value, /)
| Return self+value.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __lt__(self, value, /)
| Return self<value.
|
| __ne__(self, value, /)
| Return self!=value.
|
| __radd__(self, value, /)
| Return value+self.
|
| __reduce__(...)
| __reduce__() -> (cls, state)
|
| __reduce_ex__(...)
| __reduce_ex__(proto) -> (cls, state)
|
| __repr__(self, /)
| Return repr(self).
|
| __rsub__(self, value, /)
| Return value-self.
|
| __str__(self, /)
| Return str(self).
|
| __sub__(self, value, /)
| Return self-value.
|
| astimezone(...)
| tz -> convert to local time in new timezone tz
|
| ctime(...)
| Return ctime() style string.
|
| date(...)
| Return date object with same year, month and day.
|
| dst(...)
| Return self.tzinfo.dst(self).
|
| isoformat(...)
| [sep] -> string in ISO 8601 format, YYYY-MM-DDT[HH[:MM[:SS[.mmm[uuu]]]]][+HH:MM].
| sep is used to separate the year from the time, and defaults to 'T'.
| timespec specifies what components of the time to include (allowed values are 'auto', 'hours', 'minutes', 'seconds', 'milliseconds', and 'microseconds').
|
| replace(...)
| Return datetime with new specified fields.
|
| time(...)
| Return time object with same time but with tzinfo=None.
|
| timestamp(...)
| Return POSIX timestamp as float.
|
| timetuple(...)
| Return time tuple, compatible with time.localtime().
|
| timetz(...)
| Return time object with same time and tzinfo.
|
| tzname(...)
| Return self.tzinfo.tzname(self).
|
| utcoffset(...)
| Return self.tzinfo.utcoffset(self).
|
| utctimetuple(...)
| Return UTC time tuple, compatible with time.localtime().
|
| ----------------------------------------------------------------------
| Class methods defined here:
|
| combine(...) from builtins.type
| date, time -> datetime with same date and time fields
|
| fromisoformat(...) from builtins.type
| string -> datetime from datetime.isoformat() output
|
| fromtimestamp(...) from builtins.type
| timestamp[, tz] -> tz's local time from POSIX timestamp.
|
| now(tz=None) from builtins.type
| Returns new datetime object representing current time local to tz.
|
| tz
| Timezone object.
|
| If no tz is specified, uses local timezone.
|
| strptime(...) from builtins.type
| string, format -> new datetime parsed from a string (like time.strptime()).
|
| utcfromtimestamp(...) from builtins.type
| Construct a naive UTC datetime from a POSIX timestamp.
|
| utcnow(...) from builtins.type
| Return a new datetime representing UTC day and time.
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| fold
|
| hour
|
| microsecond
|
| minute
|
| second
|
| tzinfo
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| max = datetime.datetime(9999, 12, 31, 23, 59, 59, 999999)
|
| min = datetime.datetime(1, 1, 1, 0, 0)
|
| resolution = datetime.timedelta(microseconds=1)
|
| ----------------------------------------------------------------------
| Methods inherited from date:
|
| __format__(...)
| Formats self with strftime.
|
| isocalendar(...)
| Return a 3-tuple containing ISO year, week number, and weekday.
|
| isoweekday(...)
| Return the day of the week represented by the date.
| Monday == 1 ... Sunday == 7
|
| strftime(...)
| format -> strftime() style string.
|
| toordinal(...)
| Return proleptic Gregorian ordinal. January 1 of year 1 is day 1.
|
| weekday(...)
| Return the day of the week represented by the date.
| Monday == 0 ... Sunday == 6
|
| ----------------------------------------------------------------------
| Class methods inherited from date:
|
| fromisocalendar(...) from builtins.type
| int, int, int -> Construct a date from the ISO year, week number and weekday.
|
| This is the inverse of the date.isocalendar() function
|
| fromordinal(...) from builtins.type
| int -> date corresponding to a proleptic Gregorian ordinal.
|
| today(...) from builtins.type
| Current date or datetime: same as self.__class__.fromtimestamp(time.time()).
|
| ----------------------------------------------------------------------
| Data descriptors inherited from date:
|
| day
|
| month
|
| year
class time(builtins.object)
| time([hour[, minute[, second[, microsecond[, tzinfo]]]]]) --> a time object
|
| All arguments are optional. tzinfo may be None, or an instance of
| a tzinfo subclass. The remaining arguments may be ints.
|
| Methods defined here:
|
| __eq__(self, value, /)
| Return self==value.
|
| __format__(...)
| Formats self with strftime.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __lt__(self, value, /)
| Return self<value.
|
| __ne__(self, value, /)
| Return self!=value.
|
| __reduce__(...)
| __reduce__() -> (cls, state)
|
| __reduce_ex__(...)
| __reduce_ex__(proto) -> (cls, state)
|
| __repr__(self, /)
| Return repr(self).
|
| __str__(self, /)
| Return str(self).
|
| dst(...)
| Return self.tzinfo.dst(self).
|
| isoformat(...)
| Return string in ISO 8601 format, [HH[:MM[:SS[.mmm[uuu]]]]][+HH:MM].
|
| timespec specifies what components of the time to include.
|
| replace(...)
| Return time with new specified fields.
|
| strftime(...)
| format -> strftime() style string.
|
| tzname(...)
| Return self.tzinfo.tzname(self).
|
| utcoffset(...)
| Return self.tzinfo.utcoffset(self).
|
| ----------------------------------------------------------------------
| Class methods defined here:
|
| fromisoformat(...) from builtins.type
| string -> time from time.isoformat() output
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| fold
|
| hour
|
| microsecond
|
| minute
|
| second
|
| tzinfo
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| max = datetime.time(23, 59, 59, 999999)
|
| min = datetime.time(0, 0)
|
| resolution = datetime.timedelta(microseconds=1)
class timedelta(builtins.object)
| Difference between two datetime values.
|
| timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)
|
| All arguments are optional and default to 0.
| Arguments may be integers or floats, and may be positive or negative.
|
| Methods defined here:
|
| __abs__(self, /)
| abs(self)
|
| __add__(self, value, /)
| Return self+value.
|
| __bool__(self, /)
| self != 0
|
| __divmod__(self, value, /)
| Return divmod(self, value).
|
| __eq__(self, value, /)
| Return self==value.
|
| __floordiv__(self, value, /)
| Return self//value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __lt__(self, value, /)
| Return self<value.
|
| __mod__(self, value, /)
| Return self%value.
|
| __mul__(self, value, /)
| Return self*value.
|
| __ne__(self, value, /)
| Return self!=value.
|
| __neg__(self, /)
| -self
|
| __pos__(self, /)
| +self
|
| __radd__(self, value, /)
| Return value+self.
|
| __rdivmod__(self, value, /)
| Return divmod(value, self).
|
| __reduce__(...)
| __reduce__() -> (cls, state)
|
| __repr__(self, /)
| Return repr(self).
|
| __rfloordiv__(self, value, /)
| Return value//self.
|
| __rmod__(self, value, /)
| Return value%self.
|
| __rmul__(self, value, /)
| Return value*self.
|
| __rsub__(self, value, /)
| Return value-self.
|
| __rtruediv__(self, value, /)
| Return value/self.
|
| __str__(self, /)
| Return str(self).
|
| __sub__(self, value, /)
| Return self-value.
|
| __truediv__(self, value, /)
| Return self/value.
|
| total_seconds(...)
| Total seconds in the duration.
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| days
| Number of days.
|
| microseconds
| Number of microseconds (>= 0 and less than 1 second).
|
| seconds
| Number of seconds (>= 0 and less than 1 day).
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| max = datetime.timedelta(days=999999999, seconds=86399, microseconds=9...
|
| min = datetime.timedelta(days=-999999999)
|
| resolution = datetime.timedelta(microseconds=1)
class timezone(tzinfo)
| Fixed offset from UTC implementation of tzinfo.
|
| Method resolution order:
| timezone
| tzinfo
| builtins.object
|
| Methods defined here:
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getinitargs__(...)
| pickle support
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __lt__(self, value, /)
| Return self<value.
|
| __ne__(self, value, /)
| Return self!=value.
|
| __repr__(self, /)
| Return repr(self).
|
| __str__(self, /)
| Return str(self).
|
| dst(...)
| Return None.
|
| fromutc(...)
| datetime in UTC -> datetime in local time.
|
| tzname(...)
| If name is specified when timezone is created, returns the name. Otherwise returns offset as 'UTC(+|-)HH:MM'.
|
| utcoffset(...)
| Return fixed offset.
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| max = datetime.timezone(datetime.timedelta(seconds=86340))
|
| min = datetime.timezone(datetime.timedelta(days=-1, seconds=60))
|
| utc = datetime.timezone.utc
|
| ----------------------------------------------------------------------
| Methods inherited from tzinfo:
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __reduce__(...)
| -> (cls, state)
class tzinfo(builtins.object)
| Abstract base class for time zone info objects.
|
| Methods defined here:
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __reduce__(...)
| -> (cls, state)
|
| dst(...)
| datetime -> DST offset as timedelta positive east of UTC.
|
| fromutc(...)
| datetime in UTC -> datetime in local time.
|
| tzname(...)
| datetime -> string name of time zone.
|
| utcoffset(...)
| datetime -> timedelta showing offset from UTC, negative values indicating West of UTC
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
