datetime
— Basic date and time types¶
Source code: Lib/datetime.py
The datetime
module supplies classes for manipulating dates and times.
While date and time arithmetic is supported, the focus of the implementation is on efficient attribute extraction for output formatting and manipulation.
Wskazówka
Skip to the format codes.
Zobacz także
- Module
calendar
General calendar related functions.
- Module
time
Time access and conversions.
- Module
zoneinfo
Concrete time zones representing the IANA time zone database.
- Package dateutil
Third-party library with expanded time zone and parsing support.
- Package DateType
Third-party library that introduces distinct static types to e.g. allow static type checkers to differentiate between naive and aware datetimes.
Aware and Naive Objects¶
Date and time objects may be categorized as „aware” or „naive” depending on whether or not they include time zone information.
With sufficient knowledge of applicable algorithmic and political time adjustments, such as time zone and daylight saving time information, an aware object can locate itself relative to other aware objects. An aware object represents a specific moment in time that is not open to interpretation. [1]
A naive object does not contain enough information to unambiguously locate itself relative to other date/time objects. Whether a naive object represents Coordinated Universal Time (UTC), local time, or time in some other time zone is purely up to the program, just like it is up to the program whether a particular number represents metres, miles, or mass. Naive objects are easy to understand and to work with, at the cost of ignoring some aspects of reality.
For applications requiring aware objects, datetime
and time
objects have an optional time zone information attribute, tzinfo
, that
can be set to an instance of a subclass of the abstract tzinfo
class.
These tzinfo
objects capture information about the offset from UTC
time, the time zone name, and whether daylight saving time is in effect.
Only one concrete tzinfo
class, the timezone
class, is
supplied by the datetime
module. The timezone
class can
represent simple time zones with fixed offsets from UTC, such as UTC itself or
North American EST and EDT time zones. Supporting time zones at deeper levels of
detail is up to the application. The rules for time adjustment across the
world are more political than rational, change frequently, and there is no
standard suitable for every application aside from UTC.
Stały¶
The datetime
module exports the following constants:
- datetime.UTC¶
Alias for the UTC time zone singleton
datetime.timezone.utc
.Added in version 3.11.
Available Types¶
- class datetime.date
An idealized naive date, assuming the current Gregorian calendar always was, and always will be, in effect. Attributes:
year
,month
, andday
.
- class datetime.time
An idealized time, independent of any particular day, assuming that every day has exactly 24*60*60 seconds. (There is no notion of „leap seconds” here.) Attributes:
hour
,minute
,second
,microsecond
, andtzinfo
.
- class datetime.datetime
A combination of a date and a time. Attributes:
year
,month
,day
,hour
,minute
,second
,microsecond
, andtzinfo
.
- class datetime.timedelta
A duration expressing the difference between two
datetime
ordate
instances to microsecond resolution.
- class datetime.tzinfo
An abstract base class for time zone information objects. These are used by the
datetime
andtime
classes to provide a customizable notion of time adjustment (for example, to account for time zone and/or daylight saving time).
- class datetime.timezone
A class that implements the
tzinfo
abstract base class as a fixed offset from the UTC.Added in version 3.2.
Objects of these types are immutable.
Subclass relationships:
object
timedelta
tzinfo
timezone
time
date
datetime
Common Properties¶
The date
, datetime
, time
, and timezone
types
share these common features:
Determining if an Object is Aware or Naive¶
Objects of the date
type are always naive.
An object of type time
or datetime
may be aware or naive.
A datetime
object d
is aware if both of the following hold:
d.tzinfo
is notNone
d.tzinfo.utcoffset(d)
does not returnNone
Otherwise, d
is naive.
A time
object t
is aware if both of the following hold:
t.tzinfo
is notNone
t.tzinfo.utcoffset(None)
does not returnNone
.
Otherwise, t
is naive.
The distinction between aware and naive doesn’t apply to timedelta
objects.
timedelta
Objects¶
A timedelta
object represents a duration, the difference between two
datetime
or date
instances.
- class datetime.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.
Only days, seconds and microseconds are stored internally. Arguments are converted to those units:
A millisecond is converted to 1000 microseconds.
A minute is converted to 60 seconds.
An hour is converted to 3600 seconds.
A week is converted to 7 days.
and days, seconds and microseconds are then normalized so that the representation is unique, with
0 <= microseconds < 1000000
0 <= seconds < 3600*24
(the number of seconds in one day)-999999999 <= days <= 999999999
The following example illustrates how any arguments besides days, seconds and microseconds are „merged” and normalized into those three resulting attributes:
>>> from datetime import timedelta >>> delta = timedelta( ... days=50, ... seconds=27, ... microseconds=10, ... milliseconds=29000, ... minutes=5, ... hours=8, ... weeks=2 ... ) >>> # Only days, seconds, and microseconds remain >>> delta datetime.timedelta(days=64, seconds=29156, microseconds=10)
If any argument is a float and there are fractional microseconds, the fractional microseconds left over from all arguments are combined and their sum is rounded to the nearest microsecond using round-half-to-even tiebreaker. If no argument is a float, the conversion and normalization processes are exact (no information is lost).
If the normalized value of days lies outside the indicated range,
OverflowError
is raised.Note that normalization of negative values may be surprising at first. For example:
>>> from datetime import timedelta >>> d = timedelta(microseconds=-1) >>> (d.days, d.seconds, d.microseconds) (-1, 86399, 999999)
Class attributes:
- timedelta.max¶
The most positive
timedelta
object,timedelta(days=999999999, hours=23, minutes=59, seconds=59, microseconds=999999)
.
- timedelta.resolution¶
The smallest possible difference between non-equal
timedelta
objects,timedelta(microseconds=1)
.
Note that, because of normalization, timedelta.max
is greater than -timedelta.min
.
-timedelta.max
is not representable as a timedelta
object.
Instance attributes (read-only):
- timedelta.days¶
Between -999,999,999 and 999,999,999 inclusive.
- timedelta.seconds¶
Between 0 and 86,399 inclusive.
Ostrzeżenie
It is a somewhat common bug for code to unintentionally use this attribute when it is actually intended to get a
total_seconds()
value instead:>>> from datetime import timedelta >>> duration = timedelta(seconds=11235813) >>> duration.days, duration.seconds (130, 3813) >>> duration.total_seconds() 11235813.0
- timedelta.microseconds¶
Between 0 and 999,999 inclusive.
Supported operations:
Operation |
Result |
---|---|
|
Sum of |
|
Difference of |
|
Delta multiplied by an integer.
Afterwards |
In general, |
|
|
Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even. |
|
Division (3) of overall duration |
|
Delta divided by a float or an int. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even. |
|
The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3) |
|
The remainder is computed as a
|
|
Computes the quotient and the remainder:
|
|
Returns a |
|
Equivalent to |
|
Equivalent to |
|
Returns a string in the form
|
|
Returns a string representation of the
|
Uwagi:
This is exact but may overflow.
This is exact and cannot overflow.
Division by zero raises
ZeroDivisionError
.-timedelta.max
is not representable as atimedelta
object.String representations of
timedelta
objects are normalized similarly to their internal representation. This leads to somewhat unusual results for negative timedeltas. For example:>>> timedelta(hours=-5) datetime.timedelta(days=-1, seconds=68400) >>> print(_) -1 day, 19:00:00
The expression
t2 - t3
will always be equal to the expressiont2 + (-t3)
except when t3 is equal totimedelta.max
; in that case the former will produce a result while the latter will overflow.
In addition to the operations listed above, timedelta
objects support
certain additions and subtractions with date
and datetime
objects (see below).
Zmienione w wersji 3.2: Floor division and true division of a timedelta
object by another
timedelta
object are now supported, as are remainder operations and
the divmod()
function. True division and multiplication of a
timedelta
object by a float
object are now supported.
timedelta
objects support equality and order comparisons.
In Boolean contexts, a timedelta
object is
considered to be true if and only if it isn’t equal to timedelta(0)
.
Instance methods:
- timedelta.total_seconds()¶
Return the total number of seconds contained in the duration. Equivalent to
td / timedelta(seconds=1)
. For interval units other than seconds, use the division form directly (e.g.td / timedelta(microseconds=1)
).Note that for very large time intervals (greater than 270 years on most platforms) this method will lose microsecond accuracy.
Added in version 3.2.
Examples of usage: timedelta
¶
An additional example of normalization:
>>> # Components of another_year add up to exactly 365 days
>>> from datetime import timedelta
>>> year = timedelta(days=365)
>>> another_year = timedelta(weeks=40, days=84, hours=23,
... minutes=50, seconds=600)
>>> year == another_year
True
>>> year.total_seconds()
31536000.0
Examples of timedelta
arithmetic:
>>> from datetime import timedelta
>>> year = timedelta(days=365)
>>> ten_years = 10 * year
>>> ten_years
datetime.timedelta(days=3650)
>>> ten_years.days // 365
10
>>> nine_years = ten_years - year
>>> nine_years
datetime.timedelta(days=3285)
>>> three_years = nine_years // 3
>>> three_years, three_years.days // 365
(datetime.timedelta(days=1095), 3)
date
Objects¶
A date
object represents a date (year, month and day) in an idealized
calendar, the current Gregorian calendar indefinitely extended in both
directions.
January 1 of year 1 is called day number 1, January 2 of year 1 is called day number 2, and so on. [2]
- class datetime.date(year, month, day)¶
All arguments are required. Arguments must be integers, in the following ranges:
MINYEAR <= year <= MAXYEAR
1 <= month <= 12
1 <= day <= number of days in the given month and year
If an argument outside those ranges is given,
ValueError
is raised.
Other constructors, all class methods:
- classmethod date.today()¶
Return the current local date.
This is equivalent to
date.fromtimestamp(time.time())
.
- classmethod date.fromtimestamp(timestamp)¶
Return the local date corresponding to the POSIX timestamp, such as is returned by
time.time()
.This may raise
OverflowError
, if the timestamp is out of the range of values supported by the platform Clocaltime()
function, andOSError
onlocaltime()
failure. It’s common for this to be restricted to years from 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored byfromtimestamp()
.Zmienione w wersji 3.3: Raise
OverflowError
instead ofValueError
if the timestamp is out of the range of values supported by the platform Clocaltime()
function. RaiseOSError
instead ofValueError
onlocaltime()
failure.
- classmethod date.fromordinal(ordinal)¶
Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.
ValueError
is raised unless1 <= ordinal <= date.max.toordinal()
. For any dated
,date.fromordinal(d.toordinal()) == d
.
- classmethod date.fromisoformat(date_string)¶
Return a
date
corresponding to a date_string given in any valid ISO 8601 format, with the following exceptions:Reduced precision dates are not currently supported (
YYYY-MM
,YYYY
).Extended date representations are not currently supported (
±YYYYYY-MM-DD
).Ordinal dates are not currently supported (
YYYY-OOO
).
Przykłady:
>>> from datetime import date >>> date.fromisoformat('2019-12-04') datetime.date(2019, 12, 4) >>> date.fromisoformat('20191204') datetime.date(2019, 12, 4) >>> date.fromisoformat('2021-W01-1') datetime.date(2021, 1, 4)
Added in version 3.7.
Zmienione w wersji 3.11: Previously, this method only supported the format
YYYY-MM-DD
.
- classmethod date.fromisocalendar(year, week, day)¶
Return a
date
corresponding to the ISO calendar date specified by year, week and day. This is the inverse of the functiondate.isocalendar()
.Added in version 3.8.
Class attributes:
- date.min¶
The earliest representable date,
date(MINYEAR, 1, 1)
.
- date.max¶
The latest representable date,
date(MAXYEAR, 12, 31)
.
- date.resolution¶
The smallest possible difference between non-equal date objects,
timedelta(days=1)
.
Instance attributes (read-only):
- date.month¶
Between 1 and 12 inclusive.
- date.day¶
Between 1 and the number of days in the given month of the given year.
Supported operations:
Operation |
Result |
---|---|
|
|
|
Computes |
|
(3) |
date1 == date2 date1 != date2 |
Equality comparison. (4) |
date1 < date2 date1 > date2 date1 <= date2 date1 >= date2 |
Order comparison. (5) |
Uwagi:
date2 is moved forward in time if
timedelta.days > 0
, or backward iftimedelta.days < 0
. Afterwarddate2 - date1 == timedelta.days
.timedelta.seconds
andtimedelta.microseconds
are ignored.OverflowError
is raised ifdate2.year
would be smaller thanMINYEAR
or larger thanMAXYEAR
.timedelta.seconds
andtimedelta.microseconds
are ignored.This is exact, and cannot overflow.
timedelta.seconds
andtimedelta.microseconds
are 0, anddate2 + timedelta == date1
after.date
objects are equal if they represent the same date.date1 is considered less than date2 when date1 precedes date2 in time. In other words,
date1 < date2
if and only ifdate1.toordinal() < date2.toordinal()
.
In Boolean contexts, all date
objects are considered to be true.
Instance methods:
- date.replace(year=self.year, month=self.month, day=self.day)¶
Return a date with the same value, except for those parameters given new values by whichever keyword arguments are specified.
Przykład:
>>> from datetime import date >>> d = date(2002, 12, 31) >>> d.replace(day=26) datetime.date(2002, 12, 26)
- date.timetuple()¶
Return a
time.struct_time
such as returned bytime.localtime()
.The hours, minutes and seconds are 0, and the DST flag is -1.
d.timetuple()
is equivalent to:time.struct_time((d.year, d.month, d.day, 0, 0, 0, d.weekday(), yday, -1))
where
yday = d.toordinal() - date(d.year, 1, 1).toordinal() + 1
is the day number within the current year starting with 1 for January 1st.
- date.toordinal()¶
Return the proleptic Gregorian ordinal of the date, where January 1 of year 1 has ordinal 1. For any
date
objectd
,date.fromordinal(d.toordinal()) == d
.
- date.weekday()¶
Return the day of the week as an integer, where Monday is 0 and Sunday is 6. For example,
date(2002, 12, 4).weekday() == 2
, a Wednesday. See alsoisoweekday()
.
- date.isoweekday()¶
Return the day of the week as an integer, where Monday is 1 and Sunday is 7. For example,
date(2002, 12, 4).isoweekday() == 3
, a Wednesday. See alsoweekday()
,isocalendar()
.
- date.isocalendar()¶
Return a named tuple object with three components:
year
,week
andweekday
.The ISO calendar is a widely used variant of the Gregorian calendar. [3]
The ISO year consists of 52 or 53 full weeks, and where a week starts on a Monday and ends on a Sunday. The first week of an ISO year is the first (Gregorian) calendar week of a year containing a Thursday. This is called week number 1, and the ISO year of that Thursday is the same as its Gregorian year.
For example, 2004 begins on a Thursday, so the first week of ISO year 2004 begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan 2004:
>>> from datetime import date >>> date(2003, 12, 29).isocalendar() datetime.IsoCalendarDate(year=2004, week=1, weekday=1) >>> date(2004, 1, 4).isocalendar() datetime.IsoCalendarDate(year=2004, week=1, weekday=7)
Zmienione w wersji 3.9: Result changed from a tuple to a named tuple.
- date.isoformat()¶
Return a string representing the date in ISO 8601 format,
YYYY-MM-DD
:>>> from datetime import date >>> date(2002, 12, 4).isoformat() '2002-12-04'
- date.__str__()¶
For a date
d
,str(d)
is equivalent tod.isoformat()
.
- date.ctime()¶
Return a string representing the date:
>>> from datetime import date >>> date(2002, 12, 4).ctime() 'Wed Dec 4 00:00:00 2002'
d.ctime()
is equivalent to:time.ctime(time.mktime(d.timetuple()))
on platforms where the native C
ctime()
function (whichtime.ctime()
invokes, but whichdate.ctime()
does not invoke) conforms to the C standard.
- date.strftime(format)¶
Return a string representing the date, controlled by an explicit format string. Format codes referring to hours, minutes or seconds will see 0 values. See also strftime() and strptime() Behavior and
date.isoformat()
.
- date.__format__(format)¶
Same as
date.strftime()
. This makes it possible to specify a format string for adate
object in formatted string literals and when usingstr.format()
. See also strftime() and strptime() Behavior anddate.isoformat()
.
Examples of Usage: date
¶
Example of counting days to an event:
>>> import time
>>> from datetime import date
>>> today = date.today()
>>> today
datetime.date(2007, 12, 5)
>>> today == date.fromtimestamp(time.time())
True
>>> my_birthday = date(today.year, 6, 24)
>>> if my_birthday < today:
... my_birthday = my_birthday.replace(year=today.year + 1)
...
>>> my_birthday
datetime.date(2008, 6, 24)
>>> time_to_birthday = abs(my_birthday - today)
>>> time_to_birthday.days
202
More examples of working with date
:
>>> from datetime import date
>>> d = date.fromordinal(730920) # 730920th day after 1. 1. 0001
>>> d
datetime.date(2002, 3, 11)
>>> # Methods related to formatting string output
>>> d.isoformat()
'2002-03-11'
>>> d.strftime("%d/%m/%y")
'11/03/02'
>>> d.strftime("%A %d. %B %Y")
'Monday 11. March 2002'
>>> d.ctime()
'Mon Mar 11 00:00:00 2002'
>>> 'The {1} is {0:%d}, the {2} is {0:%B}.'.format(d, "day", "month")
'The day is 11, the month is March.'
>>> # Methods for to extracting 'components' under different calendars
>>> t = d.timetuple()
>>> for i in t:
... print(i)
2002 # year
3 # month
11 # day
0
0
0
0 # weekday (0 = Monday)
70 # 70th day in the year
-1
>>> ic = d.isocalendar()
>>> for i in ic:
... print(i)
2002 # ISO year
11 # ISO week number
1 # ISO day number ( 1 = Monday )
>>> # A date object is immutable; all operations produce a new object
>>> d.replace(year=2005)
datetime.date(2005, 3, 11)
datetime
Objects¶
A datetime
object is a single object containing all the information
from a date
object and a time
object.
Like a date
object, datetime
assumes the current Gregorian
calendar extended in both directions; like a time
object,
datetime
assumes there are exactly 3600*24 seconds in every day.
Constructor:
- class datetime.datetime(year, month, day, hour=0, minute=0, second=0, microsecond=0, tzinfo=None, *, fold=0)¶
The year, month and day arguments are required. tzinfo may be
None
, or an instance of atzinfo
subclass. The remaining arguments must be integers in the following ranges:MINYEAR <= year <= MAXYEAR
,1 <= month <= 12
,1 <= day <= number of days in the given month and year
,0 <= hour < 24
,0 <= minute < 60
,0 <= second < 60
,0 <= microsecond < 1000000
,fold in [0, 1]
.
If an argument outside those ranges is given,
ValueError
is raised.Zmienione w wersji 3.6: Added the fold parameter.
Other constructors, all class methods:
- classmethod datetime.today()¶
Return the current local date and time, with
tzinfo
None
.Odpowiednik:
datetime.fromtimestamp(time.time())
See also
now()
,fromtimestamp()
.This method is functionally equivalent to
now()
, but without atz
parameter.
- classmethod datetime.now(tz=None)¶
Return the current local date and time.
If optional argument tz is
None
or not specified, this is liketoday()
, but, if possible, supplies more precision than can be gotten from going through atime.time()
timestamp (for example, this may be possible on platforms supplying the Cgettimeofday()
function).If tz is not
None
, it must be an instance of atzinfo
subclass, and the current date and time are converted to tz’s time zone.This function is preferred over
today()
andutcnow()
.Informacja
Subsequent calls to
datetime.now()
may return the same instant depending on the precision of the underlying clock.
- classmethod datetime.utcnow()¶
Return the current UTC date and time, with
tzinfo
None
.This is like
now()
, but returns the current UTC date and time, as a naivedatetime
object. An aware current UTC datetime can be obtained by callingdatetime.now(timezone.utc)
. See alsonow()
.Ostrzeżenie
Because naive
datetime
objects are treated by manydatetime
methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing the current time in UTC is by callingdatetime.now(timezone.utc)
.Niezalecane od wersji 3.12: Use
datetime.now()
withUTC
instead.
- classmethod datetime.fromtimestamp(timestamp, tz=None)¶
Return the local date and time corresponding to the POSIX timestamp, such as is returned by
time.time()
. If optional argument tz isNone
or not specified, the timestamp is converted to the platform’s local date and time, and the returneddatetime
object is naive.If tz is not
None
, it must be an instance of atzinfo
subclass, and the timestamp is converted to tz’s time zone.fromtimestamp()
may raiseOverflowError
, if the timestamp is out of the range of values supported by the platform Clocaltime()
orgmtime()
functions, andOSError
onlocaltime()
orgmtime()
failure. It’s common for this to be restricted to years in 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored byfromtimestamp()
, and then it’s possible to have two timestamps differing by a second that yield identicaldatetime
objects. This method is preferred overutcfromtimestamp()
.Zmienione w wersji 3.3: Raise
OverflowError
instead ofValueError
if the timestamp is out of the range of values supported by the platform Clocaltime()
orgmtime()
functions. RaiseOSError
instead ofValueError
onlocaltime()
orgmtime()
failure.Zmienione w wersji 3.6:
fromtimestamp()
may return instances withfold
set to 1.
- classmethod datetime.utcfromtimestamp(timestamp)¶
Return the UTC
datetime
corresponding to the POSIX timestamp, withtzinfo
None
. (The resulting object is naive.)This may raise
OverflowError
, if the timestamp is out of the range of values supported by the platform Cgmtime()
function, andOSError
ongmtime()
failure. It’s common for this to be restricted to years in 1970 through 2038.To get an aware
datetime
object, callfromtimestamp()
:datetime.fromtimestamp(timestamp, timezone.utc)
On the POSIX compliant platforms, it is equivalent to the following expression:
datetime(1970, 1, 1, tzinfo=timezone.utc) + timedelta(seconds=timestamp)
except the latter formula always supports the full years range: between
MINYEAR
andMAXYEAR
inclusive.Ostrzeżenie
Because naive
datetime
objects are treated by manydatetime
methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing a specific timestamp in UTC is by callingdatetime.fromtimestamp(timestamp, tz=timezone.utc)
.Zmienione w wersji 3.3: Raise
OverflowError
instead ofValueError
if the timestamp is out of the range of values supported by the platform Cgmtime()
function. RaiseOSError
instead ofValueError
ongmtime()
failure.Niezalecane od wersji 3.12: Use
datetime.fromtimestamp()
withUTC
instead.
- classmethod datetime.fromordinal(ordinal)¶
Return the
datetime
corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.ValueError
is raised unless1 <= ordinal <= datetime.max.toordinal()
. The hour, minute, second and microsecond of the result are all 0, andtzinfo
isNone
.
- classmethod datetime.combine(date, time, tzinfo=time.tzinfo)¶
Return a new
datetime
object whose date components are equal to the givendate
object’s, and whose time components are equal to the giventime
object’s. If the tzinfo argument is provided, its value is used to set thetzinfo
attribute of the result, otherwise thetzinfo
attribute of the time argument is used. If the date argument is adatetime
object, its time components andtzinfo
attributes are ignored.For any
datetime
objectd
,d == datetime.combine(d.date(), d.time(), d.tzinfo)
.Zmienione w wersji 3.6: Added the tzinfo argument.
- classmethod datetime.fromisoformat(date_string)¶
Return a
datetime
corresponding to a date_string in any valid ISO 8601 format, with the following exceptions:Time zone offsets may have fractional seconds.
The
T
separator may be replaced by any single unicode character.Fractional hours and minutes are not supported.
Reduced precision dates are not currently supported (
YYYY-MM
,YYYY
).Extended date representations are not currently supported (
±YYYYYY-MM-DD
).Ordinal dates are not currently supported (
YYYY-OOO
).
Przykłady:
>>> from datetime import datetime >>> datetime.fromisoformat('2011-11-04') datetime.datetime(2011, 11, 4, 0, 0) >>> datetime.fromisoformat('20111104') datetime.datetime(2011, 11, 4, 0, 0) >>> datetime.fromisoformat('2011-11-04T00:05:23') datetime.datetime(2011, 11, 4, 0, 5, 23) >>> datetime.fromisoformat('2011-11-04T00:05:23Z') datetime.datetime(2011, 11, 4, 0, 5, 23, tzinfo=datetime.timezone.utc) >>> datetime.fromisoformat('20111104T000523') datetime.datetime(2011, 11, 4, 0, 5, 23) >>> datetime.fromisoformat('2011-W01-2T00:05:23.283') datetime.datetime(2011, 1, 4, 0, 5, 23, 283000) >>> datetime.fromisoformat('2011-11-04 00:05:23.283') datetime.datetime(2011, 11, 4, 0, 5, 23, 283000) >>> datetime.fromisoformat('2011-11-04 00:05:23.283+00:00') datetime.datetime(2011, 11, 4, 0, 5, 23, 283000, tzinfo=datetime.timezone.utc) >>> datetime.fromisoformat('2011-11-04T00:05:23+04:00') datetime.datetime(2011, 11, 4, 0, 5, 23, tzinfo=datetime.timezone(datetime.timedelta(seconds=14400)))
Added in version 3.7.
Zmienione w wersji 3.11: Previously, this method only supported formats that could be emitted by
date.isoformat()
ordatetime.isoformat()
.
- classmethod datetime.fromisocalendar(year, week, day)¶
Return a
datetime
corresponding to the ISO calendar date specified by year, week and day. The non-date components of the datetime are populated with their normal default values. This is the inverse of the functiondatetime.isocalendar()
.Added in version 3.8.
- classmethod datetime.strptime(date_string, format)¶
Return a
datetime
corresponding to date_string, parsed according to format.If format does not contain microseconds or time zone information, this is equivalent to:
datetime(*(time.strptime(date_string, format)[0:6]))
ValueError
is raised if the date_string and format can’t be parsed bytime.strptime()
or if it returns a value which isn’t a time tuple. See also strftime() and strptime() Behavior anddatetime.fromisoformat()
.
Class attributes:
- datetime.max¶
The latest representable
datetime
,datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, tzinfo=None)
.
- datetime.resolution¶
The smallest possible difference between non-equal
datetime
objects,timedelta(microseconds=1)
.
Instance attributes (read-only):
- datetime.month¶
Between 1 and 12 inclusive.
- datetime.day¶
Between 1 and the number of days in the given month of the given year.
- datetime.hour¶
In
range(24)
.
- datetime.minute¶
In
range(60)
.
- datetime.second¶
In
range(60)
.
- datetime.microsecond¶
In
range(1000000)
.
- datetime.tzinfo¶
The object passed as the tzinfo argument to the
datetime
constructor, orNone
if none was passed.
- datetime.fold¶
In
[0, 1]
. Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The values 0 and 1 represent, respectively, the earlier and later of the two moments with the same wall time representation.Added in version 3.6.
Supported operations:
Operation |
Result |
---|---|
|
(1) |
|
(2) |
|
(3) |
datetime1 == datetime2 datetime1 != datetime2 |
Equality comparison. (4) |
datetime1 < datetime2 datetime1 > datetime2 datetime1 <= datetime2 datetime1 >= datetime2 |
Order comparison. (5) |
datetime2
is a duration oftimedelta
removed fromdatetime1
, moving forward in time iftimedelta.days > 0
, or backward iftimedelta.days < 0
. The result has the sametzinfo
attribute as the input datetime, anddatetime2 - datetime1 == timedelta
after.OverflowError
is raised ifdatetime2.year
would be smaller thanMINYEAR
or larger thanMAXYEAR
. Note that no time zone adjustments are done even if the input is an aware object.Computes the
datetime2
such thatdatetime2 + timedelta == datetime1
. As for addition, the result has the sametzinfo
attribute as the input datetime, and no time zone adjustments are done even if the input is aware.Subtraction of a
datetime
from adatetime
is defined only if both operands are naive, or if both are aware. If one is aware and the other is naive,TypeError
is raised.If both are naive, or both are aware and have the same
tzinfo
attribute, thetzinfo
attributes are ignored, and the result is atimedelta
objectt
such thatdatetime2 + t == datetime1
. No time zone adjustments are done in this case.If both are aware and have different
tzinfo
attributes,a-b
acts as ifa
andb
were first converted to naive UTC datetimes. The result is(a.replace(tzinfo=None) - a.utcoffset()) - (b.replace(tzinfo=None) - b.utcoffset())
except that the implementation never overflows.datetime
objects are equal if they represent the same date and time, taking into account the time zone.Naive and aware
datetime
objects are never equal.datetime
objects are never equal todate
objects that are not alsodatetime
instances, even if they represent the same date.If both comparands are aware, and have the same
tzinfo
attribute, thetzinfo
andfold
attributes are ignored and the base datetimes are compared. If both comparands are aware and have differenttzinfo
attributes, the comparison acts as comparands were first converted to UTC datetimes except that the implementation never overflows.datetime
instances in a repeated interval are never equal todatetime
instances in other time zone.datetime1 is considered less than datetime2 when datetime1 precedes datetime2 in time, taking into account the time zone.
Order comparison between naive and aware
datetime
objects, as well as adatetime
object and adate
object that is not also adatetime
instance, raisesTypeError
.If both comparands are aware, and have the same
tzinfo
attribute, thetzinfo
andfold
attributes are ignored and the base datetimes are compared. If both comparands are aware and have differenttzinfo
attributes, the comparison acts as comparands were first converted to UTC datetimes except that the implementation never overflows.
Zmienione w wersji 3.3: Equality comparisons between aware and naive datetime
instances don’t raise TypeError
.
Instance methods:
- datetime.time()¶
Return
time
object with same hour, minute, second, microsecond and fold.tzinfo
isNone
. See also methodtimetz()
.Zmienione w wersji 3.6: The fold value is copied to the returned
time
object.
- datetime.timetz()¶
Return
time
object with same hour, minute, second, microsecond, fold, and tzinfo attributes. See also methodtime()
.Zmienione w wersji 3.6: The fold value is copied to the returned
time
object.
- datetime.replace(year=self.year, month=self.month, day=self.day, hour=self.hour, minute=self.minute, second=self.second, microsecond=self.microsecond, tzinfo=self.tzinfo, *, fold=0)¶
Return a datetime with the same attributes, except for those attributes given new values by whichever keyword arguments are specified. Note that
tzinfo=None
can be specified to create a naive datetime from an aware datetime with no conversion of date and time data.Zmienione w wersji 3.6: Added the fold parameter.
- datetime.astimezone(tz=None)¶
Return a
datetime
object with newtzinfo
attribute tz, adjusting the date and time data so the result is the same UTC time as self, but in tz’s local time.If provided, tz must be an instance of a
tzinfo
subclass, and itsutcoffset()
anddst()
methods must not returnNone
. If self is naive, it is presumed to represent time in the system time zone.If called without arguments (or with
tz=None
) the system local time zone is assumed for the target time zone. The.tzinfo
attribute of the converted datetime instance will be set to an instance oftimezone
with the zone name and offset obtained from the OS.If
self.tzinfo
is tz,self.astimezone(tz)
is equal to self: no adjustment of date or time data is performed. Else the result is local time in the time zone tz, representing the same UTC time as self: afterastz = dt.astimezone(tz)
,astz - astz.utcoffset()
will have the same date and time data asdt - dt.utcoffset()
.If you merely want to attach a
timezone
object tz to a datetime dt without adjustment of date and time data, usedt.replace(tzinfo=tz)
. If you merely want to remove thetimezone
object from an aware datetime dt without conversion of date and time data, usedt.replace(tzinfo=None)
.Note that the default
tzinfo.fromutc()
method can be overridden in atzinfo
subclass to affect the result returned byastimezone()
. Ignoring error cases,astimezone()
acts like:def astimezone(self, tz): if self.tzinfo is tz: return self # Convert self to UTC, and attach the new timezone object. utc = (self - self.utcoffset()).replace(tzinfo=tz) # Convert from UTC to tz's local time. return tz.fromutc(utc)
Zmienione w wersji 3.3: tz now can be omitted.
Zmienione w wersji 3.6: The
astimezone()
method can now be called on naive instances that are presumed to represent system local time.
- datetime.utcoffset()¶
If
tzinfo
isNone
, returnsNone
, else returnsself.tzinfo.utcoffset(self)
, and raises an exception if the latter doesn’t returnNone
or atimedelta
object with magnitude less than one day.Zmienione w wersji 3.7: The UTC offset is not restricted to a whole number of minutes.
- datetime.dst()¶
If
tzinfo
isNone
, returnsNone
, else returnsself.tzinfo.dst(self)
, and raises an exception if the latter doesn’t returnNone
or atimedelta
object with magnitude less than one day.Zmienione w wersji 3.7: The DST offset is not restricted to a whole number of minutes.
- datetime.tzname()¶
If
tzinfo
isNone
, returnsNone
, else returnsself.tzinfo.tzname(self)
, raises an exception if the latter doesn’t returnNone
or a string object,
- datetime.timetuple()¶
Return a
time.struct_time
such as returned bytime.localtime()
.d.timetuple()
is equivalent to:time.struct_time((d.year, d.month, d.day, d.hour, d.minute, d.second, d.weekday(), yday, dst))
where
yday = d.toordinal() - date(d.year, 1, 1).toordinal() + 1
is the day number within the current year starting with 1 for January 1st. Thetm_isdst
flag of the result is set according to thedst()
method:tzinfo
isNone
ordst()
returnsNone
,tm_isdst
is set to-1
; else ifdst()
returns a non-zero value,tm_isdst
is set to 1; elsetm_isdst
is set to 0.
- datetime.utctimetuple()¶
If
datetime
instanced
is naive, this is the same asd.timetuple()
except thattm_isdst
is forced to 0 regardless of whatd.dst()
returns. DST is never in effect for a UTC time.If
d
is aware,d
is normalized to UTC time, by subtractingd.utcoffset()
, and atime.struct_time
for the normalized time is returned.tm_isdst
is forced to 0. Note that anOverflowError
may be raised ifd.year
wasMINYEAR
orMAXYEAR
and UTC adjustment spills over a year boundary.Ostrzeżenie
Because naive
datetime
objects are treated by manydatetime
methods as local times, it is preferred to use aware datetimes to represent times in UTC; as a result, usingdatetime.utctimetuple()
may give misleading results. If you have a naivedatetime
representing UTC, usedatetime.replace(tzinfo=timezone.utc)
to make it aware, at which point you can usedatetime.timetuple()
.
- datetime.toordinal()¶
Return the proleptic Gregorian ordinal of the date. The same as
self.date().toordinal()
.
- datetime.timestamp()¶
Return POSIX timestamp corresponding to the
datetime
instance. The return value is afloat
similar to that returned bytime.time()
.Naive
datetime
instances are assumed to represent local time and this method relies on the platform Cmktime()
function to perform the conversion. Sincedatetime
supports wider range of values thanmktime()
on many platforms, this method may raiseOverflowError
orOSError
for times far in the past or far in the future.For aware
datetime
instances, the return value is computed as:(dt - datetime(1970, 1, 1, tzinfo=timezone.utc)).total_seconds()
Added in version 3.3.
Zmienione w wersji 3.6: The
timestamp()
method uses thefold
attribute to disambiguate the times during a repeated interval.Informacja
There is no method to obtain the POSIX timestamp directly from a naive
datetime
instance representing UTC time. If your application uses this convention and your system time zone is not set to UTC, you can obtain the POSIX timestamp by supplyingtzinfo=timezone.utc
:timestamp = dt.replace(tzinfo=timezone.utc).timestamp()
or by calculating the timestamp directly:
timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)
- datetime.weekday()¶
Return the day of the week as an integer, where Monday is 0 and Sunday is 6. The same as
self.date().weekday()
. See alsoisoweekday()
.
- datetime.isoweekday()¶
Return the day of the week as an integer, where Monday is 1 and Sunday is 7. The same as
self.date().isoweekday()
. See alsoweekday()
,isocalendar()
.
- datetime.isocalendar()¶
Return a named tuple with three components:
year
,week
andweekday
. The same asself.date().isocalendar()
.
- datetime.isoformat(sep='T', timespec='auto')¶
Return a string representing the date and time in ISO 8601 format:
YYYY-MM-DDTHH:MM:SS.ffffff
, ifmicrosecond
is not 0YYYY-MM-DDTHH:MM:SS
, ifmicrosecond
is 0
If
utcoffset()
does not returnNone
, a string is appended, giving the UTC offset:YYYY-MM-DDTHH:MM:SS.ffffff+HH:MM[:SS[.ffffff]]
, ifmicrosecond
is not 0YYYY-MM-DDTHH:MM:SS+HH:MM[:SS[.ffffff]]
, ifmicrosecond
is 0
Przykłady:
>>> from datetime import datetime, timezone >>> datetime(2019, 5, 18, 15, 17, 8, 132263).isoformat() '2019-05-18T15:17:08.132263' >>> datetime(2019, 5, 18, 15, 17, tzinfo=timezone.utc).isoformat() '2019-05-18T15:17:00+00:00'
The optional argument sep (default
'T'
) is a one-character separator, placed between the date and time portions of the result. For example:>>> from datetime import tzinfo, timedelta, datetime >>> class TZ(tzinfo): ... """A time zone with an arbitrary, constant -06:39 offset.""" ... def utcoffset(self, dt): ... return timedelta(hours=-6, minutes=-39) ... >>> datetime(2002, 12, 25, tzinfo=TZ()).isoformat(' ') '2002-12-25 00:00:00-06:39' >>> datetime(2009, 11, 27, microsecond=100, tzinfo=TZ()).isoformat() '2009-11-27T00:00:00.000100-06:39'
The optional argument timespec specifies the number of additional components of the time to include (the default is
'auto'
). It can be one of the following:'auto'
: Same as'seconds'
ifmicrosecond
is 0, same as'microseconds'
otherwise.'hours'
: Include thehour
in the two-digitHH
format.'seconds'
: Includehour
,minute
, andsecond
inHH:MM:SS
format.'milliseconds'
: Include full time, but truncate fractional second part to milliseconds.HH:MM:SS.sss
format.'microseconds'
: Include full time inHH:MM:SS.ffffff
format.
Informacja
Excluded time components are truncated, not rounded.
ValueError
will be raised on an invalid timespec argument:>>> from datetime import datetime >>> datetime.now().isoformat(timespec='minutes') '2002-12-25T00:00' >>> dt = datetime(2015, 1, 1, 12, 30, 59, 0) >>> dt.isoformat(timespec='microseconds') '2015-01-01T12:30:59.000000'
Zmienione w wersji 3.6: Added the timespec parameter.
- datetime.ctime()¶
Return a string representing the date and time:
>>> from datetime import datetime >>> datetime(2002, 12, 4, 20, 30, 40).ctime() 'Wed Dec 4 20:30:40 2002'
The output string will not include time zone information, regardless of whether the input is aware or naive.
d.ctime()
is equivalent to:time.ctime(time.mktime(d.timetuple()))
on platforms where the native C
ctime()
function (whichtime.ctime()
invokes, but whichdatetime.ctime()
does not invoke) conforms to the C standard.
- datetime.strftime(format)¶
Return a string representing the date and time, controlled by an explicit format string. See also strftime() and strptime() Behavior and
datetime.isoformat()
.
- datetime.__format__(format)¶
Same as
datetime.strftime()
. This makes it possible to specify a format string for adatetime
object in formatted string literals and when usingstr.format()
. See also strftime() and strptime() Behavior anddatetime.isoformat()
.
Examples of Usage: datetime
¶
Examples of working with datetime
objects:
>>> from datetime import datetime, date, time, timezone
>>> # Using datetime.combine()
>>> d = date(2005, 7, 14)
>>> t = time(12, 30)
>>> datetime.combine(d, t)
datetime.datetime(2005, 7, 14, 12, 30)
>>> # Using datetime.now()
>>> datetime.now()
datetime.datetime(2007, 12, 6, 16, 29, 43, 79043) # GMT +1
>>> datetime.now(timezone.utc)
datetime.datetime(2007, 12, 6, 15, 29, 43, 79060, tzinfo=datetime.timezone.utc)
>>> # Using datetime.strptime()
>>> dt = datetime.strptime("21/11/06 16:30", "%d/%m/%y %H:%M")
>>> dt
datetime.datetime(2006, 11, 21, 16, 30)
>>> # Using datetime.timetuple() to get tuple of all attributes
>>> tt = dt.timetuple()
>>> for it in tt:
... print(it)
...
2006 # year
11 # month
21 # day
16 # hour
30 # minute
0 # second
1 # weekday (0 = Monday)
325 # number of days since 1st January
-1 # dst - method tzinfo.dst() returned None
>>> # Date in ISO format
>>> ic = dt.isocalendar()
>>> for it in ic:
... print(it)
...
2006 # ISO year
47 # ISO week
2 # ISO weekday
>>> # Formatting a datetime
>>> dt.strftime("%A, %d. %B %Y %I:%M%p")
'Tuesday, 21. November 2006 04:30PM'
>>> 'The {1} is {0:%d}, the {2} is {0:%B}, the {3} is {0:%I:%M%p}.'.format(dt, "day", "month", "time")
'The day is 21, the month is November, the time is 04:30PM.'
The example below defines a tzinfo
subclass capturing time zone
information for Kabul, Afghanistan, which used +4 UTC until 1945
and then +4:30 UTC thereafter:
from datetime import timedelta, datetime, tzinfo, timezone
class KabulTz(tzinfo):
# Kabul used +4 until 1945, when they moved to +4:30
UTC_MOVE_DATE = datetime(1944, 12, 31, 20, tzinfo=timezone.utc)
def utcoffset(self, dt):
if dt.year < 1945:
return timedelta(hours=4)
elif (1945, 1, 1, 0, 0) <= dt.timetuple()[:5] < (1945, 1, 1, 0, 30):
# An ambiguous ("imaginary") half-hour range representing
# a 'fold' in time due to the shift from +4 to +4:30.
# If dt falls in the imaginary range, use fold to decide how
# to resolve. See PEP495.
return timedelta(hours=4, minutes=(30 if dt.fold else 0))
else:
return timedelta(hours=4, minutes=30)
def fromutc(self, dt):
# Follow same validations as in datetime.tzinfo
if not isinstance(dt, datetime):
raise TypeError("fromutc() requires a datetime argument")
if dt.tzinfo is not self:
raise ValueError("dt.tzinfo is not self")
# A custom implementation is required for fromutc as
# the input to this function is a datetime with utc values
# but with a tzinfo set to self.
# See datetime.astimezone or fromtimestamp.
if dt.replace(tzinfo=timezone.utc) >= self.UTC_MOVE_DATE:
return dt + timedelta(hours=4, minutes=30)
else:
return dt + timedelta(hours=4)
def dst(self, dt):
# Kabul does not observe daylight saving time.
return timedelta(0)
def tzname(self, dt):
if dt >= self.UTC_MOVE_DATE:
return "+04:30"
return "+04"
Usage of KabulTz
from above:
>>> tz1 = KabulTz()
>>> # Datetime before the change
>>> dt1 = datetime(1900, 11, 21, 16, 30, tzinfo=tz1)
>>> print(dt1.utcoffset())
4:00:00
>>> # Datetime after the change
>>> dt2 = datetime(2006, 6, 14, 13, 0, tzinfo=tz1)
>>> print(dt2.utcoffset())
4:30:00
>>> # Convert datetime to another time zone
>>> dt3 = dt2.astimezone(timezone.utc)
>>> dt3
datetime.datetime(2006, 6, 14, 8, 30, tzinfo=datetime.timezone.utc)
>>> dt2
datetime.datetime(2006, 6, 14, 13, 0, tzinfo=KabulTz())
>>> dt2 == dt3
True
time
Objects¶
A time
object represents a (local) time of day, independent of any particular
day, and subject to adjustment via a tzinfo
object.
- class datetime.time(hour=0, minute=0, second=0, microsecond=0, tzinfo=None, *, fold=0)¶
All arguments are optional. tzinfo may be
None
, or an instance of atzinfo
subclass. The remaining arguments must be integers in the following ranges:0 <= hour < 24
,0 <= minute < 60
,0 <= second < 60
,0 <= microsecond < 1000000
,fold in [0, 1]
.
If an argument outside those ranges is given,
ValueError
is raised. All default to 0 except tzinfo, which defaults toNone
.
Class attributes:
- time.resolution¶
The smallest possible difference between non-equal
time
objects,timedelta(microseconds=1)
, although note that arithmetic ontime
objects is not supported.
Instance attributes (read-only):
- time.hour¶
In
range(24)
.
- time.minute¶
In
range(60)
.
- time.second¶
In
range(60)
.
- time.microsecond¶
In
range(1000000)
.
- time.tzinfo¶
The object passed as the tzinfo argument to the
time
constructor, orNone
if none was passed.
- time.fold¶
In
[0, 1]
. Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The values 0 and 1 represent, respectively, the earlier and later of the two moments with the same wall time representation.Added in version 3.6.
time
objects support equality and order comparisons,
where a
is considered less than b
when a
precedes b
in time.
Naive and aware time
objects are never equal.
Order comparison between naive and aware time
objects raises
TypeError
.
If both comparands are aware, and have the same tzinfo
attribute, the tzinfo
and fold
attributes are
ignored and the base times are compared. If both comparands are aware and
have different tzinfo
attributes, the comparands are first adjusted by
subtracting their UTC offsets (obtained from self.utcoffset()
).
Zmienione w wersji 3.3: Equality comparisons between aware and naive time
instances
don’t raise TypeError
.
In Boolean contexts, a time
object is always considered to be true.
Zmienione w wersji 3.5: Before Python 3.5, a time
object was considered to be false if it
represented midnight in UTC. This behavior was considered obscure and
error-prone and has been removed in Python 3.5. See bpo-13936 for full
details.
Other constructor:
- classmethod time.fromisoformat(time_string)¶
Return a
time
corresponding to a time_string in any valid ISO 8601 format, with the following exceptions:Time zone offsets may have fractional seconds.
The leading
T
, normally required in cases where there may be ambiguity between a date and a time, is not required.Fractional seconds may have any number of digits (anything beyond 6 will be truncated).
Fractional hours and minutes are not supported.
Przykłady:
>>> from datetime import time >>> time.fromisoformat('04:23:01') datetime.time(4, 23, 1) >>> time.fromisoformat('T04:23:01') datetime.time(4, 23, 1) >>> time.fromisoformat('T042301') datetime.time(4, 23, 1) >>> time.fromisoformat('04:23:01.000384') datetime.time(4, 23, 1, 384) >>> time.fromisoformat('04:23:01,000384') datetime.time(4, 23, 1, 384) >>> time.fromisoformat('04:23:01+04:00') datetime.time(4, 23, 1, tzinfo=datetime.timezone(datetime.timedelta(seconds=14400))) >>> time.fromisoformat('04:23:01Z') datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc) >>> time.fromisoformat('04:23:01+00:00') datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc)
Added in version 3.7.
Zmienione w wersji 3.11: Previously, this method only supported formats that could be emitted by
time.isoformat()
.
Instance methods:
- time.replace(hour=self.hour, minute=self.minute, second=self.second, microsecond=self.microsecond, tzinfo=self.tzinfo, *, fold=0)¶
Return a
time
with the same value, except for those attributes given new values by whichever keyword arguments are specified. Note thattzinfo=None
can be specified to create a naivetime
from an awaretime
, without conversion of the time data.Zmienione w wersji 3.6: Added the fold parameter.
- time.isoformat(timespec='auto')¶
Return a string representing the time in ISO 8601 format, one of:
HH:MM:SS.ffffff
, ifmicrosecond
is not 0HH:MM:SS
, ifmicrosecond
is 0HH:MM:SS.ffffff+HH:MM[:SS[.ffffff]]
, ifutcoffset()
does not returnNone
HH:MM:SS+HH:MM[:SS[.ffffff]]
, ifmicrosecond
is 0 andutcoffset()
does not returnNone
The optional argument timespec specifies the number of additional components of the time to include (the default is
'auto'
). It can be one of the following:'auto'
: Same as'seconds'
ifmicrosecond
is 0, same as'microseconds'
otherwise.'hours'
: Include thehour
in the two-digitHH
format.'seconds'
: Includehour
,minute
, andsecond
inHH:MM:SS
format.'milliseconds'
: Include full time, but truncate fractional second part to milliseconds.HH:MM:SS.sss
format.'microseconds'
: Include full time inHH:MM:SS.ffffff
format.
Informacja
Excluded time components are truncated, not rounded.
ValueError
will be raised on an invalid timespec argument.Przykład:
>>> from datetime import time >>> time(hour=12, minute=34, second=56, microsecond=123456).isoformat(timespec='minutes') '12:34' >>> dt = time(hour=12, minute=34, second=56, microsecond=0) >>> dt.isoformat(timespec='microseconds') '12:34:56.000000' >>> dt.isoformat(timespec='auto') '12:34:56'
Zmienione w wersji 3.6: Added the timespec parameter.
- time.__str__()¶
For a time
t
,str(t)
is equivalent tot.isoformat()
.
- time.strftime(format)¶
Return a string representing the time, controlled by an explicit format string. See also strftime() and strptime() Behavior and
time.isoformat()
.
- time.__format__(format)¶
Same as
time.strftime()
. This makes it possible to specify a format string for atime
object in formatted string literals and when usingstr.format()
. See also strftime() and strptime() Behavior andtime.isoformat()
.
- time.utcoffset()¶
If
tzinfo
isNone
, returnsNone
, else returnsself.tzinfo.utcoffset(None)
, and raises an exception if the latter doesn’t returnNone
or atimedelta
object with magnitude less than one day.Zmienione w wersji 3.7: The UTC offset is not restricted to a whole number of minutes.
- time.dst()¶
If
tzinfo
isNone
, returnsNone
, else returnsself.tzinfo.dst(None)
, and raises an exception if the latter doesn’t returnNone
, or atimedelta
object with magnitude less than one day.Zmienione w wersji 3.7: The DST offset is not restricted to a whole number of minutes.
- time.tzname()¶
If
tzinfo
isNone
, returnsNone
, else returnsself.tzinfo.tzname(None)
, or raises an exception if the latter doesn’t returnNone
or a string object.
Examples of Usage: time
¶
Examples of working with a time
object:
>>> from datetime import time, tzinfo, timedelta
>>> class TZ1(tzinfo):
... def utcoffset(self, dt):
... return timedelta(hours=1)
... def dst(self, dt):
... return timedelta(0)
... def tzname(self,dt):
... return "+01:00"
... def __repr__(self):
... return f"{self.__class__.__name__}()"
...
>>> t = time(12, 10, 30, tzinfo=TZ1())
>>> t
datetime.time(12, 10, 30, tzinfo=TZ1())
>>> t.isoformat()
'12:10:30+01:00'
>>> t.dst()
datetime.timedelta(0)
>>> t.tzname()
'+01:00'
>>> t.strftime("%H:%M:%S %Z")
'12:10:30 +01:00'
>>> 'The {} is {:%H:%M}.'.format("time", t)
'The time is 12:10.'
tzinfo
Objects¶
- class datetime.tzinfo¶
This is an abstract base class, meaning that this class should not be instantiated directly. Define a subclass of
tzinfo
to capture information about a particular time zone.An instance of (a concrete subclass of)
tzinfo
can be passed to the constructors fordatetime
andtime
objects. The latter objects view their attributes as being in local time, and thetzinfo
object supports methods revealing offset of local time from UTC, the name of the time zone, and DST offset, all relative to a date or time object passed to them.You need to derive a concrete subclass, and (at least) supply implementations of the standard
tzinfo
methods needed by thedatetime
methods you use. Thedatetime
module providestimezone
, a simple concrete subclass oftzinfo
which can represent time zones with fixed offset from UTC such as UTC itself or North American EST and EDT.Special requirement for pickling: A
tzinfo
subclass must have an__init__()
method that can be called with no arguments, otherwise it can be pickled but possibly not unpickled again. This is a technical requirement that may be relaxed in the future.A concrete subclass of
tzinfo
may need to implement the following methods. Exactly which methods are needed depends on the uses made of awaredatetime
objects. If in doubt, simply implement all of them.
- tzinfo.utcoffset(dt)¶
Return offset of local time from UTC, as a
timedelta
object that is positive east of UTC. If local time is west of UTC, this should be negative.This represents the total offset from UTC; for example, if a
tzinfo
object represents both time zone and DST adjustments,utcoffset()
should return their sum. If the UTC offset isn’t known, returnNone
. Else the value returned must be atimedelta
object strictly between-timedelta(hours=24)
andtimedelta(hours=24)
(the magnitude of the offset must be less than one day). Most implementations ofutcoffset()
will probably look like one of these two:return CONSTANT # fixed-offset class return CONSTANT + self.dst(dt) # daylight-aware class
If
utcoffset()
does not returnNone
,dst()
should not returnNone
either.The default implementation of
utcoffset()
raisesNotImplementedError
.Zmienione w wersji 3.7: The UTC offset is not restricted to a whole number of minutes.
- tzinfo.dst(dt)¶
Return the daylight saving time (DST) adjustment, as a
timedelta
object orNone
if DST information isn’t known.Return
timedelta(0)
if DST is not in effect. If DST is in effect, return the offset as atimedelta
object (seeutcoffset()
for details). Note that DST offset, if applicable, has already been added to the UTC offset returned byutcoffset()
, so there’s no need to consultdst()
unless you’re interested in obtaining DST info separately. For example,datetime.timetuple()
calls itstzinfo
attribute’sdst()
method to determine how thetm_isdst
flag should be set, andtzinfo.fromutc()
callsdst()
to account for DST changes when crossing time zones.An instance tz of a
tzinfo
subclass that models both standard and daylight times must be consistent in this sense:tz.utcoffset(dt) - tz.dst(dt)
must return the same result for every
datetime
dt withdt.tzinfo == tz
. For sanetzinfo
subclasses, this expression yields the time zone’s „standard offset”, which should not depend on the date or the time, but only on geographic location. The implementation ofdatetime.astimezone()
relies on this, but cannot detect violations; it’s the programmer’s responsibility to ensure it. If atzinfo
subclass cannot guarantee this, it may be able to override the default implementation oftzinfo.fromutc()
to work correctly withastimezone()
regardless.Most implementations of
dst()
will probably look like one of these two:def dst(self, dt): # a fixed-offset class: doesn't account for DST return timedelta(0)
lub:
def dst(self, dt): # Code to set dston and dstoff to the time zone's DST # transition times based on the input dt.year, and expressed # in standard local time. if dston <= dt.replace(tzinfo=None) < dstoff: return timedelta(hours=1) else: return timedelta(0)
The default implementation of
dst()
raisesNotImplementedError
.Zmienione w wersji 3.7: The DST offset is not restricted to a whole number of minutes.
- tzinfo.tzname(dt)¶
Return the time zone name corresponding to the
datetime
object dt, as a string. Nothing about string names is defined by thedatetime
module, and there’s no requirement that it mean anything in particular. For example,"GMT"
,"UTC"
,"-500"
,"-5:00"
,"EDT"
,"US/Eastern"
,"America/New York"
are all valid replies. ReturnNone
if a string name isn’t known. Note that this is a method rather than a fixed string primarily because sometzinfo
subclasses will wish to return different names depending on the specific value of dt passed, especially if thetzinfo
class is accounting for daylight time.The default implementation of
tzname()
raisesNotImplementedError
.
These methods are called by a datetime
or time
object, in
response to their methods of the same names. A datetime
object passes
itself as the argument, and a time
object passes None
as the
argument. A tzinfo
subclass’s methods should therefore be prepared to
accept a dt argument of None
, or of class datetime
.
When None
is passed, it’s up to the class designer to decide the best
response. For example, returning None
is appropriate if the class wishes to
say that time objects don’t participate in the tzinfo
protocols. It
may be more useful for utcoffset(None)
to return the standard UTC offset, as
there is no other convention for discovering the standard offset.
When a datetime
object is passed in response to a datetime
method, dt.tzinfo
is the same object as self. tzinfo
methods can
rely on this, unless user code calls tzinfo
methods directly. The
intent is that the tzinfo
methods interpret dt as being in local
time, and not need worry about objects in other time zones.
There is one more tzinfo
method that a subclass may wish to override:
- tzinfo.fromutc(dt)¶
This is called from the default
datetime.astimezone()
implementation. When called from that,dt.tzinfo
is self, and dt’s date and time data are to be viewed as expressing a UTC time. The purpose offromutc()
is to adjust the date and time data, returning an equivalent datetime in self’s local time.Most
tzinfo
subclasses should be able to inherit the defaultfromutc()
implementation without problems. It’s strong enough to handle fixed-offset time zones, and time zones accounting for both standard and daylight time, and the latter even if the DST transition times differ in different years. An example of a time zone the defaultfromutc()
implementation may not handle correctly in all cases is one where the standard offset (from UTC) depends on the specific date and time passed, which can happen for political reasons. The default implementations ofastimezone()
andfromutc()
may not produce the result you want if the result is one of the hours straddling the moment the standard offset changes.Skipping code for error cases, the default
fromutc()
implementation acts like:def fromutc(self, dt): # raise ValueError error if dt.tzinfo is not self dtoff = dt.utcoffset() dtdst = dt.dst() # raise ValueError if dtoff is None or dtdst is None delta = dtoff - dtdst # this is self's standard offset if delta: dt += delta # convert to standard local time dtdst = dt.dst() # raise ValueError if dtdst is None if dtdst: return dt + dtdst else: return dt
In the following tzinfo_examples.py
file there are some examples of
tzinfo
classes:
from datetime import tzinfo, timedelta, datetime
ZERO = timedelta(0)
HOUR = timedelta(hours=1)
SECOND = timedelta(seconds=1)
# A class capturing the platform's idea of local time.
# (May result in wrong values on historical times in
# timezones where UTC offset and/or the DST rules had
# changed in the past.)
import time as _time
STDOFFSET = timedelta(seconds = -_time.timezone)
if _time.daylight:
DSTOFFSET = timedelta(seconds = -_time.altzone)
else:
DSTOFFSET = STDOFFSET
DSTDIFF = DSTOFFSET - STDOFFSET
class LocalTimezone(tzinfo):
def fromutc(self, dt):
assert dt.tzinfo is self
stamp = (dt - datetime(1970, 1, 1, tzinfo=self)) // SECOND
args = _time.localtime(stamp)[:6]
dst_diff = DSTDIFF // SECOND
# Detect fold
fold = (args == _time.localtime(stamp - dst_diff))
return datetime(*args, microsecond=dt.microsecond,
tzinfo=self, fold=fold)
def utcoffset(self, dt):
if self._isdst(dt):
return DSTOFFSET
else:
return STDOFFSET
def dst(self, dt):
if self._isdst(dt):
return DSTDIFF
else:
return ZERO
def tzname(self, dt):
return _time.tzname[self._isdst(dt)]
def _isdst(self, dt):
tt = (dt.year, dt.month, dt.day,
dt.hour, dt.minute, dt.second,
dt.weekday(), 0, 0)
stamp = _time.mktime(tt)
tt = _time.localtime(stamp)
return tt.tm_isdst > 0
Local = LocalTimezone()
# A complete implementation of current DST rules for major US time zones.
def first_sunday_on_or_after(dt):
days_to_go = 6 - dt.weekday()
if days_to_go:
dt += timedelta(days_to_go)
return dt
# US DST Rules
#
# This is a simplified (i.e., wrong for a few cases) set of rules for US
# DST start and end times. For a complete and up-to-date set of DST rules
# and timezone definitions, visit the Olson Database (or try pytz):
# http://www.twinsun.com/tz/tz-link.htm
# https://sourceforge.net/projects/pytz/ (might not be up-to-date)
#
# In the US, since 2007, DST starts at 2am (standard time) on the second
# Sunday in March, which is the first Sunday on or after Mar 8.
DSTSTART_2007 = datetime(1, 3, 8, 2)
# and ends at 2am (DST time) on the first Sunday of Nov.
DSTEND_2007 = datetime(1, 11, 1, 2)
# From 1987 to 2006, DST used to start at 2am (standard time) on the first
# Sunday in April and to end at 2am (DST time) on the last
# Sunday of October, which is the first Sunday on or after Oct 25.
DSTSTART_1987_2006 = datetime(1, 4, 1, 2)
DSTEND_1987_2006 = datetime(1, 10, 25, 2)
# From 1967 to 1986, DST used to start at 2am (standard time) on the last
# Sunday in April (the one on or after April 24) and to end at 2am (DST time)
# on the last Sunday of October, which is the first Sunday
# on or after Oct 25.
DSTSTART_1967_1986 = datetime(1, 4, 24, 2)
DSTEND_1967_1986 = DSTEND_1987_2006
def us_dst_range(year):
# Find start and end times for US DST. For years before 1967, return
# start = end for no DST.
if 2006 < year:
dststart, dstend = DSTSTART_2007, DSTEND_2007
elif 1986 < year < 2007:
dststart, dstend = DSTSTART_1987_2006, DSTEND_1987_2006
elif 1966 < year < 1987:
dststart, dstend = DSTSTART_1967_1986, DSTEND_1967_1986
else:
return (datetime(year, 1, 1), ) * 2
start = first_sunday_on_or_after(dststart.replace(year=year))
end = first_sunday_on_or_after(dstend.replace(year=year))
return start, end
class USTimeZone(tzinfo):
def __init__(self, hours, reprname, stdname, dstname):
self.stdoffset = timedelta(hours=hours)
self.reprname = reprname
self.stdname = stdname
self.dstname = dstname
def __repr__(self):
return self.reprname
def tzname(self, dt):
if self.dst(dt):
return self.dstname
else:
return self.stdname
def utcoffset(self, dt):
return self.stdoffset + self.dst(dt)
def dst(self, dt):
if dt is None or dt.tzinfo is None:
# An exception may be sensible here, in one or both cases.
# It depends on how you want to treat them. The default
# fromutc() implementation (called by the default astimezone()
# implementation) passes a datetime with dt.tzinfo is self.
return ZERO
assert dt.tzinfo is self
start, end = us_dst_range(dt.year)
# Can't compare naive to aware objects, so strip the timezone from
# dt first.
dt = dt.replace(tzinfo=None)
if start + HOUR <= dt < end - HOUR:
# DST is in effect.
return HOUR
if end - HOUR <= dt < end:
# Fold (an ambiguous hour): use dt.fold to disambiguate.
return ZERO if dt.fold else HOUR
if start <= dt < start + HOUR:
# Gap (a non-existent hour): reverse the fold rule.
return HOUR if dt.fold else ZERO
# DST is off.
return ZERO
def fromutc(self, dt):
assert dt.tzinfo is self
start, end = us_dst_range(dt.year)
start = start.replace(tzinfo=self)
end = end.replace(tzinfo=self)
std_time = dt + self.stdoffset
dst_time = std_time + HOUR
if end <= dst_time < end + HOUR:
# Repeated hour
return std_time.replace(fold=1)
if std_time < start or dst_time >= end:
# Standard time
return std_time
if start <= std_time < end - HOUR:
# Daylight saving time
return dst_time
Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
Central = USTimeZone(-6, "Central", "CST", "CDT")
Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")
Note that there are unavoidable subtleties twice per year in a tzinfo
subclass accounting for both standard and daylight time, at the DST transition
points. For concreteness, consider US Eastern (UTC -0500), where EDT begins the
minute after 1:59 (EST) on the second Sunday in March, and ends the minute after
1:59 (EDT) on the first Sunday in November:
UTC 3:MM 4:MM 5:MM 6:MM 7:MM 8:MM
EST 22:MM 23:MM 0:MM 1:MM 2:MM 3:MM
EDT 23:MM 0:MM 1:MM 2:MM 3:MM 4:MM
start 22:MM 23:MM 0:MM 1:MM 3:MM 4:MM
end 23:MM 0:MM 1:MM 1:MM 2:MM 3:MM
When DST starts (the „start” line), the local wall clock leaps from 1:59 to
3:00. A wall time of the form 2:MM doesn’t really make sense on that day, so
astimezone(Eastern)
won’t deliver a result with hour == 2
on the day DST
begins. For example, at the Spring forward transition of 2016, we get:
>>> from datetime import datetime, timezone
>>> from tzinfo_examples import HOUR, Eastern
>>> u0 = datetime(2016, 3, 13, 5, tzinfo=timezone.utc)
>>> for i in range(4):
... u = u0 + i*HOUR
... t = u.astimezone(Eastern)
... print(u.time(), 'UTC =', t.time(), t.tzname())
...
05:00:00 UTC = 00:00:00 EST
06:00:00 UTC = 01:00:00 EST
07:00:00 UTC = 03:00:00 EDT
08:00:00 UTC = 04:00:00 EDT
When DST ends (the „end” line), there’s a potentially worse problem: there’s an
hour that can’t be spelled unambiguously in local wall time: the last hour of
daylight time. In Eastern, that’s times of the form 5:MM UTC on the day
daylight time ends. The local wall clock leaps from 1:59 (daylight time) back
to 1:00 (standard time) again. Local times of the form 1:MM are ambiguous.
astimezone()
mimics the local clock’s behavior by mapping two adjacent UTC
hours into the same local hour then. In the Eastern example, UTC times of the
form 5:MM and 6:MM both map to 1:MM when converted to Eastern, but earlier times
have the fold
attribute set to 0 and the later times have it set to 1.
For example, at the Fall back transition of 2016, we get:
>>> u0 = datetime(2016, 11, 6, 4, tzinfo=timezone.utc)
>>> for i in range(4):
... u = u0 + i*HOUR
... t = u.astimezone(Eastern)
... print(u.time(), 'UTC =', t.time(), t.tzname(), t.fold)
...
04:00:00 UTC = 00:00:00 EDT 0
05:00:00 UTC = 01:00:00 EDT 0
06:00:00 UTC = 01:00:00 EST 1
07:00:00 UTC = 02:00:00 EST 0
Note that the datetime
instances that differ only by the value of the
fold
attribute are considered equal in comparisons.
Applications that can’t bear wall-time ambiguities should explicitly check the
value of the fold
attribute or avoid using hybrid
tzinfo
subclasses; there are no ambiguities when using timezone
,
or any other fixed-offset tzinfo
subclass (such as a class representing
only EST (fixed offset -5 hours), or only EDT (fixed offset -4 hours)).
Zobacz także
zoneinfo
The
datetime
module has a basictimezone
class (for handling arbitrary fixed offsets from UTC) and itstimezone.utc
attribute (a UTCtimezone
instance).
zoneinfo
brings the IANA time zone database (also known as the Olson database) to Python, and its usage is recommended.
- IANA time zone database
The Time Zone Database (often called tz, tzdata or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules.
timezone
Objects¶
The timezone
class is a subclass of tzinfo
, each
instance of which represents a time zone defined by a fixed offset from
UTC.
Objects of this class cannot be used to represent time zone information in the locations where different offsets are used in different days of the year or where historical changes have been made to civil time.
- class datetime.timezone(offset, name=None)¶
The offset argument must be specified as a
timedelta
object representing the difference between the local time and UTC. It must be strictly between-timedelta(hours=24)
andtimedelta(hours=24)
, otherwiseValueError
is raised.The name argument is optional. If specified it must be a string that will be used as the value returned by the
datetime.tzname()
method.Added in version 3.2.
Zmienione w wersji 3.7: The UTC offset is not restricted to a whole number of minutes.
- timezone.utcoffset(dt)¶
Return the fixed value specified when the
timezone
instance is constructed.The dt argument is ignored. The return value is a
timedelta
instance equal to the difference between the local time and UTC.Zmienione w wersji 3.7: The UTC offset is not restricted to a whole number of minutes.
- timezone.tzname(dt)¶
Return the fixed value specified when the
timezone
instance is constructed.If name is not provided in the constructor, the name returned by
tzname(dt)
is generated from the value of theoffset
as follows. If offset istimedelta(0)
, the name is „UTC”, otherwise it is a string in the formatUTC±HH:MM
, where ± is the sign ofoffset
, HH and MM are two digits ofoffset.hours
andoffset.minutes
respectively.Zmienione w wersji 3.6: Name generated from
offset=timedelta(0)
is now plain'UTC'
, not'UTC+00:00'
.
- timezone.dst(dt)¶
Always returns
None
.
- timezone.fromutc(dt)¶
Return
dt + offset
. The dt argument must be an awaredatetime
instance, withtzinfo
set toself
.
Class attributes:
- timezone.utc¶
The UTC time zone,
timezone(timedelta(0))
.
strftime()
and strptime()
Behavior¶
date
, datetime
, and time
objects all support a
strftime(format)
method, to create a string representing the time under the
control of an explicit format string.
Conversely, the datetime.strptime()
class method creates a
datetime
object from a string representing a date and time and a
corresponding format string.
The table below provides a high-level comparison of strftime()
versus strptime()
:
|
|
|
---|---|---|
Usage |
Convert object to a string according to a given format |
Parse a string into a |
Type of method |
Instance method |
Class method |
Method of |
||
Signature |
|
|
strftime()
and strptime()
Format Codes¶
These methods accept format codes that can be used to parse and format dates:
>>> datetime.strptime('31/01/22 23:59:59.999999',
... '%d/%m/%y %H:%M:%S.%f')
datetime.datetime(2022, 1, 31, 23, 59, 59, 999999)
>>> _.strftime('%a %d %b %Y, %I:%M%p')
'Mon 31 Jan 2022, 11:59PM'
The following is a list of all the format codes that the 1989 C standard requires, and these work on all platforms with a standard C implementation.
Directive |
Znaczenie |
Przykład |
Notatki |
---|---|---|---|
|
Weekday as locale’s abbreviated name. |
Sun, Mon, …, Sat
(en_US);
So, Mo, …, Sa
(de_DE)
|
(1) |
|
Weekday as locale’s full name. |
Sunday, Monday, …,
Saturday (en_US);
Sonntag, Montag, …,
Samstag (de_DE)
|
(1) |
|
Weekday as a decimal number, where 0 is Sunday and 6 is Saturday. |
0, 1, …, 6 |
|
|
Day of the month as a zero-padded decimal number. |
01, 02, …, 31 |
(9) |
|
Month as locale’s abbreviated name. |
Jan, Feb, …, Dec
(en_US);
Jan, Feb, …, Dez
(de_DE)
|
(1) |
|
Month as locale’s full name. |
January, February,
…, December (en_US);
Januar, Februar, …,
Dezember (de_DE)
|
(1) |
|
Month as a zero-padded decimal number. |
01, 02, …, 12 |
(9) |
|
Year without century as a zero-padded decimal number. |
00, 01, …, 99 |
(9) |
|
Year with century as a decimal number. |
0001, 0002, …, 2013, 2014, …, 9998, 9999 |
(2) |
|
Hour (24-hour clock) as a zero-padded decimal number. |
00, 01, …, 23 |
(9) |
|
Hour (12-hour clock) as a zero-padded decimal number. |
01, 02, …, 12 |
(9) |
|
Locale’s equivalent of either AM or PM. |
AM, PM (en_US);
am, pm (de_DE)
|
(1), (3) |
|
Minute as a zero-padded decimal number. |
00, 01, …, 59 |
(9) |
|
Second as a zero-padded decimal number. |
00, 01, …, 59 |
(4), (9) |
|
Microsecond as a decimal number, zero-padded to 6 digits. |
000000, 000001, …, 999999 |
(5) |
|
UTC offset in the form
|
(empty), +0000, -0400, +1030, +063415, -030712.345216 |
(6) |
|
Time zone name (empty string if the object is naive). |
(empty), UTC, GMT |
(6) |
|
Day of the year as a zero-padded decimal number. |
001, 002, …, 366 |
(9) |
|
Week number of the year (Sunday as the first day of the week) as a zero-padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0. |
00, 01, …, 53 |
(7), (9) |
|
Week number of the year (Monday as the first day of the week) as a zero-padded decimal number. All days in a new year preceding the first Monday are considered to be in week 0. |
00, 01, …, 53 |
(7), (9) |
|
Locale’s appropriate date and time representation. |
Tue Aug 16 21:30:00
1988 (en_US);
Di 16 Aug 21:30:00
1988 (de_DE)
|
(1) |
|
Locale’s appropriate date representation. |
08/16/88 (None);
08/16/1988 (en_US);
16.08.1988 (de_DE)
|
(1) |
|
Locale’s appropriate time representation. |
21:30:00 (en_US);
21:30:00 (de_DE)
|
(1) |
|
A literal |
% |
Several additional directives not required by the C89 standard are included for convenience. These parameters all correspond to ISO 8601 date values.
Directive |
Znaczenie |
Przykład |
Notatki |
---|---|---|---|
|
ISO 8601 year with century
representing the year that
contains the greater part of
the ISO week ( |
0001, 0002, …, 2013, 2014, …, 9998, 9999 |
(8) |
|
ISO 8601 weekday as a decimal number where 1 is Monday. |
1, 2, …, 7 |
|
|
ISO 8601 week as a decimal number with Monday as the first day of the week. Week 01 is the week containing Jan 4. |
01, 02, …, 53 |
(8), (9) |
|
UTC offset in the form
|
(empty), +00:00, -04:00, +10:30, +06:34:15, -03:07:12.345216 |
(6) |
These may not be available on all platforms when used with the strftime()
method. The ISO 8601 year and ISO 8601 week directives are not interchangeable
with the year and week number directives above. Calling strptime()
with
incomplete or ambiguous ISO 8601 directives will raise a ValueError
.
The full set of format codes supported varies across platforms, because Python
calls the platform C library’s strftime()
function, and platform
variations are common. To see the full set of format codes supported on your
platform, consult the strftime(3) documentation. There are also
differences between platforms in handling of unsupported format specifiers.
Added in version 3.6: %G
, %u
and %V
were added.
Added in version 3.12: %:z
was added.
Technical Detail¶
Broadly speaking, d.strftime(fmt)
acts like the time
module’s
time.strftime(fmt, d.timetuple())
although not all objects support a
timetuple()
method.
For the datetime.strptime()
class method, the default value is
1900-01-01T00:00:00.000
: any components not specified in the format string
will be pulled from the default value. [4]
Using datetime.strptime(date_string, format)
is equivalent to:
datetime(*(time.strptime(date_string, format)[0:6]))
except when the format includes sub-second components or time zone offset
information, which are supported in datetime.strptime
but are discarded by
time.strptime
.
For time
objects, the format codes for year, month, and day should not
be used, as time
objects have no such values. If they’re used anyway,
1900 is substituted for the year, and 1 for the month and day.
For date
objects, the format codes for hours, minutes, seconds, and
microseconds should not be used, as date
objects have no such
values. If they’re used anyway, 0 is substituted for them.
For the same reason, handling of format strings containing Unicode code points
that can’t be represented in the charset of the current locale is also
platform-dependent. On some platforms such code points are preserved intact in
the output, while on others strftime
may raise UnicodeError
or return
an empty string instead.
Uwagi:
Because the format depends on the current locale, care should be taken when making assumptions about the output value. Field orderings will vary (for example, „month/day/year” versus „day/month/year”), and the output may contain non-ASCII characters.
The
strptime()
method can parse years in the full [1, 9999] range, but years < 1000 must be zero-filled to 4-digit width.Zmienione w wersji 3.2: In previous versions,
strftime()
method was restricted to years >= 1900.Zmienione w wersji 3.3: In version 3.2,
strftime()
method was restricted to years >= 1000.When used with the
strptime()
method, the%p
directive only affects the output hour field if the%I
directive is used to parse the hour.Unlike the
time
module, thedatetime
module does not support leap seconds.When used with the
strptime()
method, the%f
directive accepts from one to six digits and zero pads on the right.%f
is an extension to the set of format characters in the C standard (but implemented separately in datetime objects, and therefore always available).For a naive object, the
%z
,%:z
and%Z
format codes are replaced by empty strings.For an aware object:
%z
utcoffset()
is transformed into a string of the form±HHMM[SS[.ffffff]]
, whereHH
is a 2-digit string giving the number of UTC offset hours,MM
is a 2-digit string giving the number of UTC offset minutes,SS
is a 2-digit string giving the number of UTC offset seconds andffffff
is a 6-digit string giving the number of UTC offset microseconds. Theffffff
part is omitted when the offset is a whole number of seconds and both theffffff
and theSS
part is omitted when the offset is a whole number of minutes. For example, ifutcoffset()
returnstimedelta(hours=-3, minutes=-30)
,%z
is replaced with the string'-0330'
.
Zmienione w wersji 3.7: The UTC offset is not restricted to a whole number of minutes.
Zmienione w wersji 3.7: When the
%z
directive is provided to thestrptime()
method, the UTC offsets can have a colon as a separator between hours, minutes and seconds. For example,'+01:00:00'
will be parsed as an offset of one hour. In addition, providing'Z'
is identical to'+00:00'
.%:z
Behaves exactly as
%z
, but has a colon separator added between hours, minutes and seconds.%Z
In
strftime()
,%Z
is replaced by an empty string iftzname()
returnsNone
; otherwise%Z
is replaced by the returned value, which must be a string.strptime()
only accepts certain values for%Z
:any value in
time.tzname
for your machine’s localethe hard-coded values
UTC
andGMT
So someone living in Japan may have
JST
,UTC
, andGMT
as valid values, but probably notEST
. It will raiseValueError
for invalid values.
Zmienione w wersji 3.2: When the
%z
directive is provided to thestrptime()
method, an awaredatetime
object will be produced. Thetzinfo
of the result will be set to atimezone
instance.When used with the
strptime()
method,%U
and%W
are only used in calculations when the day of the week and the calendar year (%Y
) are specified.Similar to
%U
and%W
,%V
is only used in calculations when the day of the week and the ISO year (%G
) are specified in astrptime()
format string. Also note that%G
and%Y
are not interchangeable.When used with the
strptime()
method, the leading zero is optional for formats%d
,%m
,%H
,%I
,%M
,%S
,%j
,%U
,%W
, and%V
. Format%y
does require a leading zero.
Przypisy