datetime — Types de base pour la date et l'heure

Code source : 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.

Voir aussi

Module calendar

Fonctions génériques associées au calendrier.

Module time

Accès au données d'horaires et aux conversions associées.

Package dateutil

Third-party library with expanded time zone and parsing support.

Aware and Naive Objects

Date and time objects may be categorized as "aware" or "naive."

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 timezone 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 timezones with fixed offsets from UTC, such as UTC itself or North American EST and EDT timezones. Supporting timezones 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.

Constantes

Le module datetime exporte les constantes suivantes :

datetime.MINYEAR

Le numéro d'année le plus petit autorisé dans un objet date ou datetime. MINYEAR vaut 1.

datetime.MAXYEAR

Le numéro d'année le plus grand autorisé dans un objet date ou datetime. MAXYEAR vaut 9999.

Types disponibles

class datetime.date

Une date naïve idéalisée, en supposant que le calendrier Grégorien actuel a toujours existé et qu'il existera toujours. Attributs : year, month et day.

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, and tzinfo.

class datetime.datetime

Une combinaison d'une date et d'une heure. Attributs : year, month, day, hour, minute, second, microsecond, et tzinfo.

class datetime.timedelta

Une durée qui exprime la différence entre deux instances de date, time ou datetime en microsecondes.

class datetime.tzinfo

An abstract base class for time zone information objects. These are used by the datetime and time classes to provide a customizable notion of time adjustment (for example, to account for time zone and/or daylight saving time).

class datetime.timezone

Une classe qui implémente la classe de base abstraite tzinfo en tant qu'offset fixe par rapport au temps UTC.

Nouveau dans la version 3.2.

Les objets issus de ces types sont immuables.

Relations entre les sous-classes :

object
    timedelta
    tzinfo
        timezone
    time
    date
        datetime

Common Properties

The date, datetime, time, and timezone types share these common features:

  • Les objets issus de ces types sont immuables.

  • Objects of these types are hashable, meaning that they can be used as dictionary keys.

  • Objects of these types support efficient pickling via the pickle module.

Determining if an Object is Aware or Naive

Les objets de type date sont toujours naïfs.

An object of type time or datetime may be aware or naive.

A datetime object d is aware if both of the following hold:

  1. d.tzinfo is not None

  2. d.tzinfo.utcoffset(d) does not return None

Otherwise, d is naive.

A time object t is aware if both of the following hold:

  1. t.tzinfo is not None

  2. t.tzinfo.utcoffset(None) does not return None.

Otherwise, t is naive.

The distinction between aware and naive doesn't apply to timedelta objects.

Objets timedelta

Un objet timedelta représente une durée, c'est-à-dire la différence entre deux dates ou heures.

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:

  • Une milliseconde est convertie en 1000 microsecondes.

  • Une minute est convertie en 60 secondes.

  • Une heure est convertie en 3600 secondes.

  • Une semaine est convertie en 7 jours.

et ensuite les jours, secondes et microsecondes sont normalisés pour que la représentation soit unique avec

  • 0 <= microseconds < 1000000

  • 0 <= secondes < 3600*24 (le nombre de secondes dans une journée)

  • -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).

Si la valeur normalisée des jours déborde de l'intervalle indiqué, une OverflowError est levée.

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)

Attributs de la classe :

timedelta.min

L'objet timedelta le plus négatif, timedelta(-999999999).

timedelta.max

L'objet timedelta le plus positif, timedelta(days=999999999, hours=23, minutes=59, seconds=59, microseconds=999999).

timedelta.resolution

La plus petite différence entre des objets timedelta non égaux, timedelta(microseconds=1).

Il est à noter, du fait de la normalisation, que timedelta.max > -timedelta.min. -timedelta.max n'est pas représentable sous la forme d'un objet timedelta.

Attributs de l'instance (en lecture seule) :

Attribut

Valeur

days

Entre -999999999 et 999999999 inclus

seconds

Entre 0 et 86399 inclus

microseconds

Entre 0 et 999999 inclus

Opérations gérées :

Opération

Résultat

t1 = t2 + t3

Somme de t2 et t3. Ensuite t1 - t2 == t3 et t1 - t3 == t2 sont des expressions vraies. (1)

t1 = t2 - t3

Différence entre t2 et t3. Ensuite t1 == t2 - t3 et t2 == t1 + t3 sont des expressions vraies. (1)(6)

t1 = t2 * i or t1 = i * t2

Delta multiplié par un entier. Ensuite t1 // i == t2 est vrai, en admettant que i != 0.

De manière générale, t1 * i == t1 * (i-1) + t1 est vrai. (1)

t1 = t2 * f or t1 = f * t2

Delta multiplié par un flottant. Le résultat est arrondi au multiple le plus proche de timedelta.resolution en utilisant la règle de l'arrondi au pair le plus proche.

f = t2 / t3

Division (3) de la durée totale t2 par l'unité d'intervalle t3. Renvoie un objet float.

t1 = t2 / f or t1 = t2 / i

Delta divisé par un flottant ou un entier. Le résultat est arrondi au multiple le plus proche de timedelta.resolution en utilisant la règle de l'arrondi au pair le plus proche.

t1 = t2 // i or t1 = t2 // t3

The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)

t1 = t2 % t3

Le reste est calculé comme un objet de type timedelta. (3)

q, r = divmod(t1, t2)

Calcule le quotient et le reste : q = t1 // t2 (3) et r = t1 % t2. q est un entier et r est un objet timedelta.

+t1

Renvoie un objet timedelta avec la même valeur. (2)

-t1

équivalent à timedelta(-t1.days, -t1.seconds, -t1.microseconds), et à t1 * -1. (1)(4)

abs(t)

équivalent à +t quand t.days >= 0, et à -t quand t.days < 0. (2)

str(t)

Renvoie une chaîne de la forme [D day[s], ][H]H:MM:SS[.UUUUUU], où D est négatif pour t négatif. (5)

repr(t)

Renvoie une chaîne de la forme objet timedelta comme un appel construit avec des valeurs d'attributs canoniques.

Notes :

  1. This is exact but may overflow.

  2. This is exact and cannot overflow.

  3. Une division par 0 provoque ZeroDivisionError.

  4. -timedelta.max n'est pas représentable avec un objet timedelta.

  5. 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
    
  6. L'expression t2 - t3 est toujours égale à l'expression t2 + (-t3) sauf si t3 vaut timedelta.max`; dans ce cas, la première expression produit une valeur alors que la seconde lève une ``OverflowError.

In addition to the operations listed above, timedelta objects support certain additions and subtractions with date and datetime objects (see below).

Modifié dans la version 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.

Comparisons of timedelta objects are supported, with some caveats.

The comparisons == or != always return a bool, no matter the type of the compared object:

>>> from datetime import timedelta
>>> delta1 = timedelta(seconds=57)
>>> delta2 = timedelta(hours=25, seconds=2)
>>> delta2 != delta1
True
>>> delta2 == 5
False

For all other comparisons (such as < and >), when a timedelta object is compared to an object of a different type, TypeError is raised:

>>> delta2 > delta1
True
>>> delta2 > 5
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: '>' not supported between instances of 'datetime.timedelta' and 'int'

In Boolean contexts, a timedelta object is considered to be true if and only if it isn't equal to timedelta(0).

Méthodes de l'instance :

timedelta.total_seconds()

Renvoie le nombre total de secondes contenues dans la durée. Équivalent à td / timedelta(seconds=1). Pour un intervalle dont l'unité n'est pas la seconde, utilisez directement la division (par exemple, td / timedelta(microseconds=1)).

Notez que pour des intervalles de temps très larges (supérieurs à 270 ans sur la plupart des plateformes), cette méthode perdra la précision des microsecondes.

Nouveau dans la 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)

Objets date

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 <= nombre de jours dans le mois et l'année donnés

Si un argument est donné en dehors de ces intervalles, une valueError est levée.

Autres constructeurs, méthodes de classe :

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 C localtime() function, and OSError on localtime() 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 by fromtimestamp().

Modifié dans la version 3.3: Lève une OverflowError plutôt qu'une ValueError si l'horodatage (timestamp en anglais) est en dehors des bornes gérées par la fonction C localtime() de la plateforme. Lève une OSError plutôt qu'une ValueError en cas d'échec de localtime().

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 unless 1 <= ordinal <= date.max.toordinal(). For any date d, date.fromordinal(d.toordinal()) == d.

classmethod date.fromisoformat(date_string)

Return a date corresponding to a date_string given in the format YYYY-MM-DD:

>>> from datetime import date
>>> date.fromisoformat('2019-12-04')
datetime.date(2019, 12, 4)

This is the inverse of date.isoformat(). It only supports the format YYYY-MM-DD.

Nouveau dans la version 3.7.

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 function date.isocalendar().

Nouveau dans la version 3.8.

Attributs de la classe :

date.min

La plus vieille date représentable, date(MINYEAR, 1, 1).

date.max

La dernière date représentable, date(MAXYEAR, 12, 31).

date.resolution

La plus petite différence possible entre deux objets dates non-égaux, timedelta(days=1).

Attributs de l'instance (en lecture seule) :

date.year

Entre MINYEAR et MAXYEAR inclus.

date.month

Entre 1 et 12 inclus.

date.day

Entre 1 et le nombre de jours du mois donné de l'année donnée.

Opérations gérées :

Opération

Résultat

date2 = date1 + timedelta

date2 is timedelta.days days removed from date1. (1)

date2 = date1 - timedelta

Calcule date2 de façon à avoir date2 + timedelta == date1. (2)

timedelta = date1 - date2

(3)

date1 < date2

date1 est considérée comme inférieure à date2 quand date1 précède date2 dans le temps. (4)

Notes :

  1. date2 is moved forward in time if timedelta.days > 0, or backward if timedelta.days < 0. Afterward date2 - date1 == timedelta.days. timedelta.seconds and timedelta.microseconds are ignored. OverflowError is raised if date2.year would be smaller than MINYEAR or larger than MAXYEAR.

  2. timedelta.seconds et timedelta.microseconds sont ignorés.

  3. This is exact, and cannot overflow. timedelta.seconds and timedelta.microseconds are 0, and date2 + timedelta == date1 after.

  4. In other words, date1 < date2 if and only if date1.toordinal() < date2.toordinal(). Date comparison raises TypeError if the other comparand isn't also a date object. However, NotImplemented is returned instead if the other comparand has a timetuple() attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a date object is compared to an object of a different type, TypeError is raised unless the comparison is == or !=. The latter cases return False or True, respectively.

In Boolean contexts, all date objects are considered to be true.

Méthodes de l'instance :

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.

Example:

>>> 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 by time.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 object d, date.fromordinal(d.toordinal()) == d.

date.weekday()

Renvoie le jour de la semaine sous forme de nombre, où lundi vaut 0 et dimanche vaut 6. Par exemple, date(2002, 12, 4).weekday() == 2, un mercredi. Voir aussi isoweekday().

date.isoweekday()

Renvoie le jour de la semaine sous forme de nombre, où lundi vaut 1 et dimanche vaut 7. Par exemple, date(2002, 12, 4).isoweekday() == 3, un mercredi. Voir aussi weekday(), isocalendar().

date.isocalendar()

Renvoie un tuple de 3 éléments, (année ISO, numéro de semaine ISO, jour de la semaine ISO).

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()
(2004, 1, 1)
>>> date(2004, 1, 4).isocalendar()
(2004, 1, 7)
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'

This is the inverse of date.fromisoformat().

date.__str__()

Pour une date d, str(d) est équivalent à d.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 (which time.ctime() invokes, but which date.ctime() does not invoke) conforms to the C standard.

date.strftime(format)

Renvoie une chaîne de caractères représentant la date, contrôlée par une chaîne de formatage explicite. Les codes de formatage se référant aux heures, minutes ou secondes auront pour valeur 0. Pour une liste complète des directives de formatage, voir Comportement de strftime() et strptime().

date.__format__(format)

Identique à date.strftime(). Cela permet de spécifier une chaîne de formatage pour un objet date dans une chaîne de formatage littérale et à l'utilisation de str.format(). Pour une liste complète des directives de formatage, voir Comportement de strftime() et strptime().

Examples of Usage: date

Exemple de décompte des jours avant un évènement :

>>> 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)

Objets datetime

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.

Constructeur :

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 a tzinfo subclass. The remaining arguments must be integers in the following ranges:

  • MINYEAR <= year <= MAXYEAR,

  • 1 <= month <= 12,

  • 1 <= day <= nombre de jours dans le mois donné de l'année donnée,

  • 0 <= hour < 24,

  • 0 <= minute < 60,

  • 0 <= second < 60,

  • 0 <= microsecond < 1000000,

  • fold in [0, 1].

Si un argument est donné en dehors de ces intervalles, une valueError est levée.

Nouveau dans la version 3.6: Ajout de l'argument fold.

Autres constructeurs, méthodes de classe :

classmethod datetime.today()

Return the current local datetime, with tzinfo None.

Équivalent à :

datetime.fromtimestamp(time.time())

See also now(), fromtimestamp().

This method is functionally equivalent to now(), but without a tz parameter.

classmethod datetime.now(tz=None)

Return the current local date and time.

If optional argument tz is None or not specified, this is like today(), but, if possible, supplies more precision than can be gotten from going through a time.time() timestamp (for example, this may be possible on platforms supplying the C gettimeofday() function).

If tz is not None, it must be an instance of a tzinfo subclass, and the current date and time are converted to tz’s time zone.

This function is preferred over today() and utcnow().

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 naive datetime object. An aware current UTC datetime can be obtained by calling datetime.now(timezone.utc). See also now().

Avertissement

Because naive datetime objects are treated by many datetime 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 by calling datetime.now(timezone.utc).

classmethod datetime.fromtimestamp(timestamp, tz=None)

Renvoie la date et l'heure locales correspondant à l'horodatage (timestamp en anglais) POSIX, comme renvoyé par time.time(). Si l'argument optionnel tz est None ou n'est pas spécifié, l'horodatage est converti vers la date et l'heure locales de la plateforme, et l'objet datetime renvoyé est naïf.

If tz is not None, it must be an instance of a tzinfo subclass, and the timestamp is converted to tz’s time zone.

fromtimestamp() may raise OverflowError, if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions, and OSError on localtime() or gmtime() 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 by fromtimestamp(), and then it's possible to have two timestamps differing by a second that yield identical datetime objects. This method is preferred over utcfromtimestamp().

Modifié dans la version 3.3: Lève une OverflowError plutôt qu'une ValueError si l'horodatage est en dehors de l'intervalle de valeurs gérées par les fonctions C localtime() ou gmtime() de la plateforme. Lève une OSError plutôt qu'une ValueError en cas d'échec de localtime() ou gmtime().

Modifié dans la version 3.6: fromtimestamp() peut renvoyer des instances avec l'attribut fold à 1.

classmethod datetime.utcfromtimestamp(timestamp)

Return the UTC datetime corresponding to the POSIX timestamp, with tzinfo None. (The resulting object is naive.)

This may raise OverflowError, if the timestamp is out of the range of values supported by the platform C gmtime() function, and OSError on gmtime() failure. It's common for this to be restricted to years in 1970 through 2038.

Pour obtenir un objet datetime avisé, appelez fromtimestamp() :

datetime.fromtimestamp(timestamp, timezone.utc)

Sur les plateformes respectant POSIX, cela est équivalent à l'expression suivante :

datetime(1970, 1, 1, tzinfo=timezone.utc) + timedelta(seconds=timestamp)

excepté que la dernière formule gère l'intervalle complet des années entre MINYEAR et MAXYEAR incluses.

Avertissement

Because naive datetime objects are treated by many datetime 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 by calling datetime.fromtimestamp(timestamp, tz=timezone.utc).

Modifié dans la version 3.3: Lève une OverflowError plutôt qu'une ValueError si l'horodatage est en dehors de l'intervalle de valeurs gérées par la fonction C gmtime() de la plateforme. Lève une OSError plutôt qu'une ValueError en cas d'échec de gmtime().

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 unless 1 <= ordinal <= datetime.max.toordinal(). The hour, minute, second and microsecond of the result are all 0, and tzinfo is None.

classmethod datetime.combine(date, time, tzinfo=self.tzinfo)

Return a new datetime object whose date components are equal to the given date object's, and whose time components are equal to the given time object's. If the tzinfo argument is provided, its value is used to set the tzinfo attribute of the result, otherwise the tzinfo attribute of the time argument is used.

For any datetime object d, d == datetime.combine(d.date(), d.time(), d.tzinfo). If date is a datetime object, its time components and tzinfo attributes are ignored.

Modifié dans la version 3.6: Ajout de l'argument tzinfo.

classmethod datetime.fromisoformat(date_string)

Return a datetime corresponding to a date_string in one of the formats emitted by date.isoformat() and datetime.isoformat().

Specifically, this function supports strings in the format:

YYYY-MM-DD[*HH[:MM[:SS[.fff[fff]]]][+HH:MM[:SS[.ffffff]]]]

where * can match any single character.

Prudence

This does not support parsing arbitrary ISO 8601 strings - it is only intended as the inverse operation of datetime.isoformat(). A more full-featured ISO 8601 parser, dateutil.parser.isoparse is available in the third-party package dateutil. This does not support parsing arbitrary ISO 8601 strings - it is only intended as the inverse operation of datetime.isoformat().

Examples:

>>> from datetime import datetime
>>> datetime.fromisoformat('2011-11-04')
datetime.datetime(2011, 11, 4, 0, 0)
>>> datetime.fromisoformat('2011-11-04T00:05:23')
datetime.datetime(2011, 11, 4, 0, 5, 23)
>>> datetime.fromisoformat('2011-11-04 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)))

Nouveau dans la version 3.7.

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 function datetime.isocalendar().

Nouveau dans la version 3.8.

classmethod datetime.strptime(date_string, format)

Return a datetime corresponding to date_string, parsed according to format.

C’est équivalent à :

datetime(*(time.strptime(date_string, format)[0:6]))

ValueError is raised if the date_string and format can't be parsed by time.strptime() or if it returns a value which isn't a time tuple. For a complete list of formatting directives, see Comportement de strftime() et strptime().

Attributs de la classe :

datetime.min

Le plus ancien datetime représentable, datetime(MINYEAR, 1, 1, tzinfo=None).

datetime.max

Le dernier datetime représentable, datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, tzinfo=None).

datetime.resolution

La plus petite différence possible entre deux objets datetime non-égaux, timedelta(microseconds=1).

Attributs de l'instance (en lecture seule) :

datetime.year

Entre MINYEAR et MAXYEAR inclus.

datetime.month

Entre 1 et 12 inclus.

datetime.day

Entre 1 et le nombre de jours du mois donné de l'année donnée.

datetime.hour

Dans range(24).

datetime.minute

Dans range(60).

datetime.second

Dans range(60).

datetime.microsecond

Dans range(1000000).

datetime.tzinfo

L'objet passé en tant que paramètre tzinfo du constructeur de la classe datetime ou None si aucun n'a été donné.

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 value 0 (1) represents the earlier (later) of the two moments with the same wall time representation.

Nouveau dans la version 3.6.

Opérations gérées :

Opération

Résultat

datetime2 = datetime1 + timedelta

(1)

datetime2 = datetime1 - timedelta

(2)

timedelta = datetime1 - datetime2

(3)

datetime1 < datetime2

Compare datetime à datetime. (4)

  1. datetime2 is a duration of timedelta removed from datetime1, moving forward in time if timedelta.days > 0, or backward if timedelta.days < 0. The result has the same tzinfo attribute as the input datetime, and datetime2 - datetime1 == timedelta after. OverflowError is raised if datetime2.year would be smaller than MINYEAR or larger than MAXYEAR. Note that no time zone adjustments are done even if the input is an aware object.

  2. Calcule datetime2 tel que datetime2 + timedelta == datetime1. Comme pour l'addition, le résultat a le même attribut tzinfo que le datetime d'entrée, et aucun ajustement de fuseau horaire n'est réalisé même si l'entrée est avisée.

  3. Subtraction of a datetime from a datetime 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, the tzinfo attributes are ignored, and the result is a timedelta object t such that datetime2 + t == datetime1. No time zone adjustments are done in this case.

    If both are aware and have different tzinfo attributes, a-b acts as if a and b were first converted to naive UTC datetimes first. The result is (a.replace(tzinfo=None) - a.utcoffset()) - (b.replace(tzinfo=None) - b.utcoffset()) except that the implementation never overflows.

  4. datetime1 est considéré inférieur à datetime2 quand il le précède dans le temps.

    If one comparand is naive and the other is aware, TypeError is raised if an order comparison is attempted. For equality comparisons, naive instances are never equal to aware instances.

    If both comparands are aware, and have the same tzinfo attribute, the common tzinfo attribute is ignored and the base datetimes 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()).

    Modifié dans la version 3.3: Equality comparisons between aware and naive datetime instances don't raise TypeError.

    Note

    In order to stop comparison from falling back to the default scheme of comparing object addresses, datetime comparison normally raises TypeError if the other comparand isn't also a datetime object. However, NotImplemented is returned instead if the other comparand has a timetuple() attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a datetime object is compared to an object of a different type, TypeError is raised unless the comparison is == or !=. The latter cases return False or True, respectively.

Méthodes de l'instance :

datetime.date()

Renvoie un objet date avec les mêmes année, mois et jour.

datetime.time()

Return time object with same hour, minute, second, microsecond and fold. tzinfo is None. See also method timetz().

Modifié dans la version 3.6: La valeur fold est copiée vers l'objet time renvoyé.

datetime.timetz()

Return time object with same hour, minute, second, microsecond, fold, and tzinfo attributes. See also method time().

Modifié dans la version 3.6: La valeur fold est copiée vers l'objet time renvoyé.

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.

Nouveau dans la version 3.6: Ajout de l'argument fold.

datetime.astimezone(tz=None)

Renvoie un objet datetime avec un nouvel attribut tzinfo valant tz, ajustant la date et l'heure pour que le résultat soit le même temps UTC que self, mais dans le temps local au fuseau tz.

If provided, tz must be an instance of a tzinfo subclass, and its utcoffset() and dst() methods must not return None. If self is naive, it is presumed to represent time in the system timezone.

If called without arguments (or with tz=None) the system local timezone is assumed for the target timezone. The .tzinfo attribute of the converted datetime instance will be set to an instance of timezone with the zone name and offset obtained from the OS.

Si self.tzinfo est tz, self.astimezone(tz) est égal à self : aucun ajustement de date ou d'heure n'est réalisé. Sinon le résultat est le temps local dans le fuseau tz représentant le même temps UTC que self : après astz = dt.astimezone(tz), astz - astz.utcoffset() aura les mêmes données de date et d'heure que dt - dt.utcoffset().

If you merely want to attach a time zone object tz to a datetime dt without adjustment of date and time data, use dt.replace(tzinfo=tz). If you merely want to remove the time zone object from an aware datetime dt without conversion of date and time data, use dt.replace(tzinfo=None).

Notez que la méthode par défaut tzinfo.fromutc() peut être redéfinie dans une sous-classe tzinfo pour affecter le résultat renvoyé par astimezone(). En ignorant les cas d'erreurs, astimezone() se comporte comme :

def astimezone(self, tz):
    if self.tzinfo is tz:
        return self
    # Convert self to UTC, and attach the new time zone object.
    utc = (self - self.utcoffset()).replace(tzinfo=tz)
    # Convert from UTC to tz's local time.
    return tz.fromutc(utc)

Modifié dans la version 3.3: tz peut maintenant être omis.

Modifié dans la version 3.6: La méthode astimezone() peut maintenant être appelée sur des instances naïves qui sont supposées représenter un temps local au système.

datetime.utcoffset()

Si tzinfo est None, renvoie None, sinon renvoie self.tzinfo.utcoffset(self), et lève une exception si l'expression précédente ne renvoie pas None ou un objet timedelta d'une magnitude inférieure à un jour.

Modifié dans la version 3.7: Le décalage UTC peut aussi être autre chose qu'un ensemble de minutes.

datetime.dst()

Si tzinfo est None, renvoie None, sinon renvoie self.tzinfo.dst(self), et lève une exception si l'expression précédente ne renvoie pas None ou un objet timedelta d'une magnitude inférieure à un jour.

Modifié dans la version 3.7: Le décalage DST n'est pas restreint à des minutes entières.

datetime.tzname()

Si tzinfo est None, renvoie None, sinon renvoie self.tzinfo.tzname(self), lève une exception si l'expression précédente ne renvoie pas None ou une chaîne de caractères,

datetime.timetuple()

Return a time.struct_time such as returned by time.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. The tm_isdst flag of the result is set according to the dst() method: tzinfo is None or dst() returns None, tm_isdst is set to -1; else if dst() returns a non-zero value, tm_isdst is set to 1; else tm_isdst is set to 0.

datetime.utctimetuple()

If datetime instance d is naive, this is the same as d.timetuple() except that tm_isdst is forced to 0 regardless of what d.dst() returns. DST is never in effect for a UTC time.

If d is aware, d is normalized to UTC time, by subtracting d.utcoffset(), and a time.struct_time for the normalized time is returned. tm_isdst is forced to 0. Note that an OverflowError may be raised if d.year was MINYEAR or MAXYEAR and UTC adjustment spills over a year boundary.

Avertissement

Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC; as a result, using utcfromtimetuple may give misleading results. If you have a naive datetime representing UTC, use datetime.replace(tzinfo=timezone.utc) to make it aware, at which point you can use datetime.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 a float similar to that returned by time.time().

Naive datetime instances are assumed to represent local time and this method relies on the platform C mktime() function to perform the conversion. Since datetime supports wider range of values than mktime() on many platforms, this method may raise OverflowError for times far in the past or far in the future.

Pour les instances datetime avisées, la valeur renvoyée est calculée comme suit :

(dt - datetime(1970, 1, 1, tzinfo=timezone.utc)).total_seconds()

Nouveau dans la version 3.3.

Modifié dans la version 3.6: La méthode timestamp() utilise l'attribut fold pour désambiguïser le temps dans un intervalle répété.

Note

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 timezone is not set to UTC, you can obtain the POSIX timestamp by supplying tzinfo=timezone.utc:

timestamp = dt.replace(tzinfo=timezone.utc).timestamp()

ou en calculant l'horodatage (timestamp en anglais) directement :

timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)
datetime.weekday()

Renvoie le jour de la semaine sous forme de nombre, où lundi vaut 0 et dimanche vaut 6. Identique à self.date().weekday(). Voir aussi isoweekday().

datetime.isoweekday()

Renvoie le jour de la semaine sous forme de nombre, où lundi vaut 1 et dimanche vaut 7. Identique à self.date().isoweekday(). Voir aussi weekday(), isocalendar().

datetime.isocalendar()

Return a 3-tuple, (ISO year, ISO week number, ISO weekday). The same as self.date().isocalendar().

datetime.isoformat(sep='T', timespec='auto')

Return a string representing the date and time in ISO 8601 format:

If utcoffset() does not return None, a string is appended, giving the UTC offset:

  • YYYY-MM-DDTHH:MM:SS.ffffff+HH:MM[:SS[.ffffff]], if microsecond is not 0

  • YYYY-MM-DDTHH:MM:SS+HH:MM[:SS[.ffffff]], if microsecond is 0

Examples:

>>> 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'

L'argument optionnel timespec spécifie le nombre de composants additionnels de temps à inclure (par défaut 'auto'). Il peut valoir l'une des valeurs suivantes :

  • 'auto' : Identique à 'seconds' si microsecond vaut 0, à 'microseconds' sinon.

  • 'hours': Include the hour in the two-digit HH format.

  • 'minutes': Include hour and minute in HH:MM format.

  • 'seconds': Include hour, minute, and second in HH:MM:SS format.

  • 'milliseconds': Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.

  • 'microseconds': Include full time in HH:MM:SS.ffffff format.

Note

Les composants de temps exclus sont tronqués et non arrondis.

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'

Nouveau dans la version 3.6: Ajout de l'argument timespec.

datetime.__str__()

Pour une instance d de datetime, str(d) est équivalent à d.isoformat(' ').

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 (which time.ctime() invokes, but which datetime.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. For a complete list of formatting directives, see Comportement de strftime() et strptime().

datetime.__format__(format)

Same as datetime.strftime(). This makes it possible to specify a format string for a datetime object in formatted string literals and when using str.format(). For a complete list of formatting directives, see Comportement de strftime() et strptime().

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

Objets time

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 a tzinfo 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 to None.

Attributs de la classe :

time.min

Le plus petit objet time représentable, time(0, 0, 0, 0).

time.max

Le plus grand objet time représentable, time(23, 59, 59, 999999).

time.resolution

La plus petite différence possible entre deux objets time non-égaux, timedelta(microseconds=1), notez cependant que les objets time n'implémentent pas d'opérations arithmétiques.

Attributs de l'instance (en lecture seule) :

time.hour

Dans range(24).

time.minute

Dans range(60).

time.second

Dans range(60).

time.microsecond

Dans range(1000000).

time.tzinfo

L'objet passé comme argument tzinfo au constructeur de time, ou None si aucune valeur n'a été passée.

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 value 0 (1) represents the earlier (later) of the two moments with the same wall time representation.

Nouveau dans la version 3.6.

time objects support comparison of time to time, where a is considered less than b when a precedes b in time. If one comparand is naive and the other is aware, TypeError is raised if an order comparison is attempted. For equality comparisons, naive instances are never equal to aware instances.

If both comparands are aware, and have the same tzinfo attribute, the common tzinfo attribute is 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()). In order to stop mixed-type comparisons from falling back to the default comparison by object address, when a time object is compared to an object of a different type, TypeError is raised unless the comparison is == or !=. The latter cases return False or True, respectively.

Modifié dans la version 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.

Modifié dans la version 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.

Autre constructeur :

classmethod time.fromisoformat(time_string)

Return a time corresponding to a time_string in one of the formats emitted by time.isoformat(). Specifically, this function supports strings in the format:

HH[:MM[:SS[.fff[fff]]]][+HH:MM[:SS[.ffffff]]]

Prudence

This does not support parsing arbitrary ISO 8601 strings. It is only intended as the inverse operation of time.isoformat().

Examples:

>>> from datetime import time
>>> time.fromisoformat('04:23:01')
datetime.time(4, 23, 1)
>>> 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)))

Nouveau dans la version 3.7.

Méthodes de l'instance :

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 that tzinfo=None can be specified to create a naive time from an aware time, without conversion of the time data.

Nouveau dans la version 3.6: Ajout de l'argument fold.

time.isoformat(timespec='auto')

Return a string representing the time in ISO 8601 format, one of:

L'argument optionnel timespec spécifie le nombre de composants additionnels de temps à inclure (par défaut 'auto'). Il peut valoir l'une des valeurs suivantes :

  • 'auto' : Identique à 'seconds' si microsecond vaut 0, à 'microseconds' sinon.

  • 'hours': Include the hour in the two-digit HH format.

  • 'minutes': Include hour and minute in HH:MM format.

  • 'seconds': Include hour, minute, and second in HH:MM:SS format.

  • 'milliseconds': Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.

  • 'microseconds': Include full time in HH:MM:SS.ffffff format.

Note

Les composants de temps exclus sont tronqués et non arrondis.

Une ValueError sera levée en cas d'argument timespec invalide.

Example:

>>> 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'

Nouveau dans la version 3.6: Ajout de l'argument timespec.

time.__str__()

Pour un temps t, str(t) est équivalent à t.isoformat().

time.strftime(format)

Return a string representing the time, controlled by an explicit format string. For a complete list of formatting directives, see Comportement de strftime() et strptime().

time.__format__(format)

Same as time.strftime(). This makes it possible to specify a format string for a time object in formatted string literals and when using str.format(). For a complete list of formatting directives, see Comportement de strftime() et strptime().

time.utcoffset()

Si tzinfo est None, renvoie None, sinon renvoie self.tzinfo.utcoffset(None), et lève une exception si l'expression précédente ne renvoie pas None ou un objet timedelta d'une magnitude inférieure à un jour.

Modifié dans la version 3.7: Le décalage UTC peut aussi être autre chose qu'un ensemble de minutes.

time.dst()

Si tzinfo est None, renvoie None, sinon renvoie self.tzinfo.dst(None), et lève une exception si l'expression précédente ne renvoie pas None ou un objet timedelta d'une magnitude inférieure à un jour.

Modifié dans la version 3.7: Le décalage DST n'est pas restreint à des minutes entières.

time.tzname()

Si tzinfo est None, renvoie None, sinon renvoie self.tzinfo.tzname(None), et lève une exception si l'expression précédente ne renvoie pas None ou une chaîne de caractères.

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.'

Objets tzinfo

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.

Une instance (d'une sous-classe concrète) de tzinfo peut être passée aux constructeurs des objets datetime et time. Les objets en question voient leurs attributs comme étant en temps local, et l'objet tzinfo contient des méthodes pour obtenir le décalage du temps local par rapport à UTC, le nom du fuseau horaire, le décalage d'heure d'été, tous relatifs à un objet de date ou d'heure qui leur est passé.

You need to derive a concrete subclass, and (at least) supply implementations of the standard tzinfo methods needed by the datetime methods you use. The datetime module provides timezone, a simple concrete subclass of tzinfo which can represent timezones 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 aware datetime 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, return None. Else the value returned must be a timedelta object strictly between -timedelta(hours=24) and timedelta(hours=24) (the magnitude of the offset must be less than one day). Most implementations of utcoffset() will probably look like one of these two:

return CONSTANT                 # fixed-offset class
return CONSTANT + self.dst(dt)  # daylight-aware class

Si utcoffset() ne renvoie pas None, dst() ne doit pas non plus renvoyer None.

L'implémentation par défaut de utcoffset() lève une NotImplementedError.

Modifié dans la version 3.7: Le décalage UTC peut aussi être autre chose qu'un ensemble de minutes.

tzinfo.dst(dt)

Return the daylight saving time (DST) adjustment, as a timedelta object or None if DST information isn't known.

Return timedelta(0) if DST is not in effect. If DST is in effect, return the offset as a timedelta object (see utcoffset() for details). Note that DST offset, if applicable, has already been added to the UTC offset returned by utcoffset(), so there's no need to consult dst() unless you're interested in obtaining DST info separately. For example, datetime.timetuple() calls its tzinfo attribute's dst() method to determine how the tm_isdst flag should be set, and tzinfo.fromutc() calls dst() to account for DST changes when crossing time zones.

Une instance tz d'une sous-classe tzinfo convenant à la fois pour une heure standard et une heure d'été doit être cohérente :

tz.utcoffset(dt) - tz.dst(dt)

must return the same result for every datetime dt with dt.tzinfo == tz For sane tzinfo 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 of datetime.astimezone() relies on this, but cannot detect violations; it's the programmer's responsibility to ensure it. If a tzinfo subclass cannot guarantee this, it may be able to override the default implementation of tzinfo.fromutc() to work correctly with astimezone() regardless.

La plupart des implémentations de dst() ressembleront probablement à l'une des deux suivantes :

def dst(self, dt):
    # a fixed-offset class:  doesn't account for DST
    return timedelta(0)

ou  :

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)

L'implémentation par défaut de dst() lève une NotImplementedError.

Modifié dans la version 3.7: Le décalage DST n'est pas restreint à des minutes entières.

tzinfo.tzname(dt)

Return the time zone name corresponding to the datetime object dt, as a string. Nothing about string names is defined by the datetime 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. Return None if a string name isn't known. Note that this is a method rather than a fixed string primarily because some tzinfo subclasses will wish to return different names depending on the specific value of dt passed, especially if the tzinfo class is accounting for daylight time.

L'implémentation par défaut de tzname() lève une NotImplementedError.

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 timezones.

Il y a une dernière méthode de tzinfo que les sous-classes peuvent vouloir redéfinir :

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 of fromutc() 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 default fromutc() 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 default fromutc() 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 of astimezone() and fromutc() may not produce the result you want if the result is one of the hours straddling the moment the standard offset changes.

En omettant le code des cas d'erreurs, l'implémentation par défaut de fromutc() se comporte comme suit :

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

Dans le fichier tzinfo_examples.py il y a des exemples de 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
# http://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.

Les applications qui ne peuvent pas gérer ces ambiguïtés doivent vérifier explicitement la valeur de l'attribut fold ou éviter d'utiliser des sous-classes tzinfo hybrides ; il n'y a aucune ambiguïté lors de l'utilisation de la classe timezone, ou toute autre sous-classe de tzinfo à décalage fixe (comme une classe représentant uniquement le fuseau EST (de décalage fixe -5h) ou uniquement EDT (-4h)).

Voir aussi

dateutil.tz

The datetime module has a basic timezone class (for handling arbitrary fixed offsets from UTC) and its timezone.utc attribute (a UTC timezone instance).

dateutil.tz library brings the IANA timezone database (also known as the Olson database) to Python, and its usage is recommended.

Base de données des fuseaux horaires de l'IANA

La Time Zone Database (souvent appelée tz, tzdata ou zoneinfo) contient les codes et les données représentant l'historique du temps local pour un grand nombre d'emplacements représentatifs autour du globe. Elle est mise à jour périodiquement, pour refléter les changements opérés par des politiques sur les bornes du fuseau, les décalages UTC, et les règles de passage à l'heure d'été.

Objets timezone

The timezone class is a subclass of tzinfo, each instance of which represents a timezone defined by a fixed offset from UTC.

Objects of this class cannot be used to represent timezone 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) and timedelta(hours=24), otherwise ValueError 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.

Nouveau dans la version 3.2.

Modifié dans la version 3.7: Le décalage UTC peut aussi être autre chose qu'un ensemble de 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.

Modifié dans la version 3.7: Le décalage UTC peut aussi être autre chose qu'un ensemble de 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 the offset as follows. If offset is timedelta(0), the name is "UTC", otherwise it is a string in the format UTC±HH:MM, where ± is the sign of offset, HH and MM are two digits of offset.hours and offset.minutes respectively.

Modifié dans la version 3.6: Name generated from offset=timedelta(0) is now plain 'UTC', not 'UTC+00:00'.

timezone.dst(dt)

Renvoie toujours None.

timezone.fromutc(dt)

Return dt + offset. The dt argument must be an aware datetime instance, with tzinfo set to self.

Attributs de la classe :

timezone.utc

Le fuseau horaire UTC, timezone(timedelta(0)).

Comportement de strftime() et strptime()

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():

strftime

strptime

Usage

Convert object to a string according to a given format

Parse a string into a datetime object given a corresponding format

Type of method

Instance method

Class method

Method of

date; datetime; time

datetime

Signature

strftime(format)

strptime(date_string, format)

strftime() and strptime() Format Codes

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

Signification

Exemple

Notes

%a

Jour de la semaine abrégé dans la langue locale.

Sun, Mon, ..., Sat (en_US);
Lu, Ma, ..., Di (fr_FR)

(1)

%A

Jour de la semaine complet dans la langue locale.

Sunday, Monday, ..., Saturday (en_US);
Lundi, Mardi, ..., Dimanche (fr_FR)

(1)

%w

Jour de la semaine en chiffre, avec 0 pour le dimanche et 6 pour le samedi.

0, 1, ..., 6

%d

Jour du mois sur deux chiffres.

01, 02, ..., 31

(9)

%b

Nom du mois abrégé dans la langue locale.

Jan, Feb, ..., Dec (en_US);
janv., févr., ..., déc. (fr_FR)

(1)

%B

Nom complet du mois dans la langue locale.

January, February, ..., December (en_US);
janvier, février, ..., décembre (fr_FR)

(1)

%m

Numéro du mois sur deux chiffres.

01, 02, ..., 12

(9)

%y

Année sur deux chiffres (sans le siècle).

00, 01, ..., 99

(9)

%Y

Année complète sur quatre chiffres.

0001, 0002, ..., 2013, 2014, ..., 9998, 9999

(2)

%H

Heure à deux chiffres de 00 à 23.

00, 01, ..., 23

(9)

%I

Heure à deux chiffres pour les horloges 12h (01 à 12).

01, 02, ..., 12

(9)

%p

Équivalent local à AM/PM.

AM, PM (en_US);
am, pm (de_DE)

(1), (3)

%M

Minutes sur deux chiffres.

00, 01, ..., 59

(9)

%S

Secondes sur deux chiffres.

00, 01, ..., 59

(4), (9)

%f

Microsecondes sur 6 chiffres.

000000, 000001, ..., 999999

(5)

%z

UTC offset in the form ±HHMM[SS[.ffffff]] (empty string if the object is naive).

(vide), +0000, -0400, +1030, +063415, -030712.345216

(6)

%Z

Nom du fuseau horaire (chaîne vide si l'instance est naïve).

(vide), UTC, EST, CST

%j

Numéro du jour dans l'année sur trois chiffres.

001, 002, ..., 366

(9)

%U

Numéro de la semaine à deux chiffres (où dimanche est considéré comme le premier jour de la semaine). Tous les jours de l'année précédent le premier dimanche sont considérés comme appartenant à la semaine 0.

00, 01, ..., 53

(7), (9)

%W

Numéro de la semaine à deux chiffres (où lundi est considéré comme le premier jour de la semaine). Tous les jours de l'année précédent le premier lundi sont considérés comme appartenant à la semaine 0.

00, 01, ..., 53

(7), (9)

%c

Représentation locale de la date et de l'heure.

Tue Aug 16 21:30:00 1988 (en_US);
mar. 16 août 1988 21:30:00 (fr_FR)

(1)

%x

Représentation locale de la date.

08/16/88 (None);
08/16/1988 (en_US);
16/08/1988 (fr_FR)

(1)

%X

Représentation locale de l'heure.

21:30:00 (en_US) ;
21:30:00 (fr_FR)

(1)

%%

Un caractère '%' littéral.

%

Several additional directives not required by the C89 standard are included for convenience. These parameters all correspond to ISO 8601 date values.

Directive

Signification

Exemple

Notes

%G

Année complète ISO 8601 représentant l'année contenant la plus grande partie de la semaine ISO (%V).

0001, 0002, ..., 2013, 2014, ..., 9998, 9999

(8)

%u

Jour de la semaine ISO 8601 où 1 correspond au lundi.

1, 2, ..., 7

%V

Numéro de la semaine ISO 8601, avec lundi étant le premier jour de la semaine. La semaine 01 est la semaine contenant le 4 janvier.

01, 02, ..., 53

(8), (9)

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.

Nouveau dans la version 3.6: %G, %u et %V ont été ajoutés.

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.

Pour la méthode datetime.strptime(), la valeur par défaut est 1900-01-01T00:00:00.000 : tous les composants non spécifiés dans la chaîne de formatage seront retirés de la valeur par défaut. 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 timezone 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.

Pour la même raison, la gestion des chaînes contenant des caractères (ou points) Unicode qui ne peuvent pas être représentés dans la locale actuelle dépend aussi de la plateforme. Sur certaines plateformes, ces caractères sont conservés tels quels dans la sortie, alors que sur d'autres plateformes strftime lève une UnicodeError ou renvoie une chaîne vide.

Notes :

  1. Comme le format dépend de la locale courante, les assomptions sur la valeur de retour doivent être prises soigneusement. L'ordre des champs variera (par exemple, « mois/jour/année » versus « année/mois/jour »), et le retour pourrait contenir des caractères Unicode encodés en utilisant l'encodage par défaut de la locale (par exemple, si la locale courante est ja_JP, l'encodage par défaut pourrait être eucJP, SJIS ou utf-8 ; utilisez locale.getlocale() pour déterminer l'encodage de la locale courante).

  2. La méthode strptime() peut analyser toutes les années de l'intervalle [1, 9999], mais toutes les années < 1000 doivent être représentées sur quatre chiffres.

    Modifié dans la version 3.2: Dans les versions précédentes, la méthode strftime() était limitée aux années >= 1900.

    Modifié dans la version 3.3: En version 3.2, la méthode strftime() était limitée aux années >= 1000.

  3. Quand utilisée avec la méthode strptime(), la directive %p n'affecte l'heure extraite que si la directive %I est utilisée pour analyser l'heure.

  4. À l'inverse du module time, le module datetime ne gère pas les secondes intercalaires.

  5. 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).

  6. Pour les objets naïfs, les codes de formatage %z et %Z sont remplacés par des chaînes vides.

    Pour un objet avisé :

    %z

    utcoffset() is transformed into a string of the form ±HHMM[SS[.ffffff]], where HH 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 and ffffff is a 6-digit string giving the number of UTC offset microseconds. The ffffff part is omitted when the offset is a whole number of seconds and both the ffffff and the SS part is omitted when the offset is a whole number of minutes. For example, if utcoffset() returns timedelta(hours=-3, minutes=-30), %z is replaced with the string '-0330'.

    Modifié dans la version 3.7: Le décalage UTC peut aussi être autre chose qu'un ensemble de minutes.

    Modifié dans la version 3.7: Quand la directive %z est soumise à la méthode strptime(), le décalage UTC peut avoir une colonne comme séparateur entre les heures, minutes et secondes. Par exemple, '+01:00:00', est analysé comme un décalage d'une heure. Par ailleurs, 'Z' est identique à '+00:00'.

    %Z

    If tzname() returns None, %Z is replaced by an empty string. Otherwise %Z is replaced by the returned value, which must be a string.

    Modifié dans la version 3.2: When the %z directive is provided to the strptime() method, an aware datetime object will be produced. The tzinfo of the result will be set to a timezone instance.

  7. Quand ces directives sont utilisées avec la méthode strptime(), %U et %W ne sont utilisées dans les calculs que si le jour de la semaine et l'année calendaire (%Y) sont spécifiés.

  8. De façon similaire à %U et %W, %v n'est utilisé dans les calculs que lorsque le jour de la semaine et l'année ISO (%G) sont spécifiés dans la chaîne de formatage strptime(). Notez aussi que %G et %Y ne sont pas interchangeables.

  9. Quand cette directive est utilisée avec la méthode strptime(), le zéro d'entête est optionnel pour les formats %d, %m, %H, %I, %M, %S, %J, %U, %W et %V. Le format %y requiert un zéro en entête.

Notes

1

Si on ignore les effets de la Relativité

2

This matches the definition of the "proleptic Gregorian" calendar in Dershowitz and Reingold's book Calendrical Calculations, where it's the base calendar for all computations. See the book for algorithms for converting between proleptic Gregorian ordinals and many other calendar systems.

3

See R. H. van Gent's guide to the mathematics of the ISO 8601 calendar for a good explanation.

4

Passer datetime.strptime(‘Feb 29’, ‘%b %d’) ne marchera pas car 1900 n’est pas une année bissextile.