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Diffstat (limited to 'Doc/library/datetime.rst')
| -rw-r--r-- | Doc/library/datetime.rst | 304 |
1 files changed, 166 insertions, 138 deletions
diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst index 9d0af67..27885f9 100644 --- a/Doc/library/datetime.rst +++ b/Doc/library/datetime.rst @@ -593,15 +593,17 @@ Instance methods: .. method:: 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 - section :ref:`strftime-strptime-behavior`. + Format codes referring to hours, minutes or seconds will see 0 values. For a + complete list of formatting directives, see + :ref:`strftime-strptime-behavior`. .. method:: date.__format__(format) Same as :meth:`.date.strftime`. This makes it possible to specify format - string for a :class:`.date` object when using :meth:`str.format`. - See section :ref:`strftime-strptime-behavior`. + string for a :class:`.date` object when using :meth:`str.format`. For a + complete list of formatting directives, see + :ref:`strftime-strptime-behavior`. Example of counting days to an event:: @@ -793,7 +795,8 @@ Other constructors, all class methods: *format*. This is equivalent to ``datetime(*(time.strptime(date_string, format)[0:6]))``. :exc:`ValueError` is raised if the date_string and format can't be parsed by :func:`time.strptime` or if it returns a value which isn't a - time tuple. See section :ref:`strftime-strptime-behavior`. + time tuple. For a complete list of formatting directives, see + :ref:`strftime-strptime-behavior`. @@ -1160,14 +1163,16 @@ Instance methods: .. method:: datetime.strftime(format) Return a string representing the date and time, controlled by an explicit format - string. See section :ref:`strftime-strptime-behavior`. + string. For a complete list of formatting directives, see + :ref:`strftime-strptime-behavior`. .. method:: datetime.__format__(format) Same as :meth:`.datetime.strftime`. This makes it possible to specify format - string for a :class:`.datetime` object when using :meth:`str.format`. - See section :ref:`strftime-strptime-behavior`. + string for a :class:`.datetime` object when using :meth:`str.format`. For a + complete list of formatting directives, see + :ref:`strftime-strptime-behavior`. Examples of working with datetime objects: @@ -1399,15 +1404,17 @@ Instance methods: .. method:: time.strftime(format) - Return a string representing the time, controlled by an explicit format string. - See section :ref:`strftime-strptime-behavior`. + Return a string representing the time, controlled by an explicit format + string. For a complete list of formatting directives, see + :ref:`strftime-strptime-behavior`. .. method:: time.__format__(format) Same as :meth:`.time.strftime`. This makes it possible to specify format string - for a :class:`.time` object when using :meth:`str.format`. - See section :ref:`strftime-strptime-behavior`. + for a :class:`.time` object when using :meth:`str.format`. For a + complete list of formatting directives, see + :ref:`strftime-strptime-behavior`. .. method:: time.utcoffset() @@ -1773,22 +1780,6 @@ For :class:`date` objects, the format codes for hours, minutes, seconds, and microseconds should not be used, as :class:`date` objects have no such values. If they're used anyway, ``0`` is substituted for them. -For a naive object, the ``%z`` and ``%Z`` format codes are replaced by empty -strings. - -For an aware object: - -``%z`` - :meth:`utcoffset` is transformed into a 5-character string of the form +HHMM or - -HHMM, where HH is a 2-digit string giving the number of UTC offset hours, and - MM is a 2-digit string giving the number of UTC offset minutes. For example, if - :meth:`utcoffset` returns ``timedelta(hours=-3, minutes=-30)``, ``%z`` is - replaced with the string ``'-0330'``. - -``%Z`` - If :meth:`tzname` returns ``None``, ``%Z`` is replaced by an empty string. - Otherwise ``%Z`` is replaced by the returned value, which must be a string. - The full set of format codes supported varies across platforms, because Python calls the platform C library's :func:`strftime` function, and platform variations are common. @@ -1798,116 +1789,119 @@ version) requires, and these work on all platforms with a standard C implementation. Note that the 1999 version of the C standard added additional format codes. -+-----------+--------------------------------+-------+ -| Directive | Meaning | Notes | -+===========+================================+=======+ -| ``%a`` | Locale's abbreviated weekday | | -| | name. | | -+-----------+--------------------------------+-------+ -| ``%A`` | Locale's full weekday name. | | -+-----------+--------------------------------+-------+ -| ``%b`` | Locale's abbreviated month | | -| | name. | | -+-----------+--------------------------------+-------+ -| ``%B`` | Locale's full month name. | | -+-----------+--------------------------------+-------+ -| ``%c`` | Locale's appropriate date and | | -| | time representation. | | -+-----------+--------------------------------+-------+ -| ``%d`` | Day of the month as a decimal | | -| | number [01,31]. | | -+-----------+--------------------------------+-------+ -| ``%f`` | Microsecond as a decimal | \(1) | -| | number [0,999999], zero-padded | | -| | on the left | | -+-----------+--------------------------------+-------+ -| ``%H`` | Hour (24-hour clock) as a | | -| | decimal number [00,23]. | | -+-----------+--------------------------------+-------+ -| ``%I`` | Hour (12-hour clock) as a | | -| | decimal number [01,12]. | | -+-----------+--------------------------------+-------+ -| ``%j`` | Day of the year as a decimal | | -| | number [001,366]. | | -+-----------+--------------------------------+-------+ -| ``%m`` | Month as a decimal number | | -| | [01,12]. | | -+-----------+--------------------------------+-------+ -| ``%M`` | Minute as a decimal number | | -| | [00,59]. | | -+-----------+--------------------------------+-------+ -| ``%p`` | Locale's equivalent of either | \(2) | -| | AM or PM. | | -+-----------+--------------------------------+-------+ -| ``%S`` | Second as a decimal number | \(3) | -| | [00,59]. | | -+-----------+--------------------------------+-------+ -| ``%U`` | Week number of the year | \(4) | -| | (Sunday as the first day of | | -| | the week) as a decimal number | | -| | [00,53]. All days in a new | | -| | year preceding the first | | -| | Sunday are considered to be in | | -| | week 0. | | -+-----------+--------------------------------+-------+ -| ``%w`` | Weekday as a decimal number | | -| | [0(Sunday),6]. | | -+-----------+--------------------------------+-------+ -| ``%W`` | Week number of the year | \(4) | -| | (Monday as the first day of | | -| | the week) as a decimal number | | -| | [00,53]. All days in a new | | -| | year preceding the first | | -| | Monday are considered to be in | | -| | week 0. | | -+-----------+--------------------------------+-------+ -| ``%x`` | Locale's appropriate date | | -| | representation. | | -+-----------+--------------------------------+-------+ -| ``%X`` | Locale's appropriate time | | -| | representation. | | -+-----------+--------------------------------+-------+ -| ``%y`` | Year without century as a | | -| | decimal number [00,99]. | | -+-----------+--------------------------------+-------+ -| ``%Y`` | Year with century as a decimal | \(5) | -| | number [0001,9999]. | | -+-----------+--------------------------------+-------+ -| ``%z`` | UTC offset in the form +HHMM | \(6) | -| | or -HHMM (empty string if the | | -| | the object is naive). | | -+-----------+--------------------------------+-------+ -| ``%Z`` | Time zone name (empty string | | -| | if the object is naive). | | -+-----------+--------------------------------+-------+ -| ``%%`` | A literal ``'%'`` character. | | -+-----------+--------------------------------+-------+ ++-----------+--------------------------------+------------------------+-------+ +| Directive | Meaning | Example | Notes | ++===========+================================+========================+=======+ +| ``%a`` | Weekday as locale's || Sun, Mon, ..., Sat | \(1) | +| | abbreviated name. | (en_US); | | +| | || So, Mo, ..., Sa | | +| | | (de_DE) | | ++-----------+--------------------------------+------------------------+-------+ +| ``%A`` | Weekday as locale's full name. || Sunday, Monday, ..., | \(1) | +| | | Saturday (en_US); | | +| | || Sonntag, Montag, ..., | | +| | | Samstag (de_DE) | | ++-----------+--------------------------------+------------------------+-------+ +| ``%w`` | Weekday as a decimal number, | 0, 1, ..., 6 | | +| | where 0 is Sunday and 6 is | | | +| | Saturday. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%d`` | Day of the month as a | 01, 02, ..., 31 | | +| | zero-padded decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%b`` | Month as locale's abbreviated || Jan, Feb, ..., Dec | \(1) | +| | name. | (en_US); | | +| | || Jan, Feb, ..., Dez | | +| | | (de_DE) | | ++-----------+--------------------------------+------------------------+-------+ +| ``%B`` | Month as locale's full name. || January, February, | \(1) | +| | | ..., December (en_US);| | +| | || Januar, Februar, ..., | | +| | | Dezember (de_DE) | | ++-----------+--------------------------------+------------------------+-------+ +| ``%m`` | Month as a zero-padded | 01, 02, ..., 12 | | +| | decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%y`` | Year without century as a | 00, 01, ..., 99 | | +| | zero-padded decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%Y`` | Year with century as a decimal | 0001, 0002, ..., 2013, | \(2) | +| | number. | 2014, ...., 9998, 9999 | | ++-----------+--------------------------------+------------------------+-------+ +| ``%H`` | Hour (24-hour clock) as a | 00, 01, ..., 23 | | +| | zero-padded decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%I`` | Hour (12-hour clock) as a | 01, 02, ..., 12 | | +| | zero-padded decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%p`` | Locale's equivalent of either || AM, PM (en_US); | \(1), | +| | AM or PM. || am, pm (de_DE) | \(3) | ++-----------+--------------------------------+------------------------+-------+ +| ``%M`` | Minute as a zero-padded | 00, 01, ..., 59 | | +| | decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%S`` | Second as a zero-padded | 00, 01, ..., 59 | \(4) | +| | decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%f`` | Microsecond as a decimal | 000000, 000001, ..., | \(5) | +| | number, zero-padded on the | 999999 | | +| | left. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%z`` | UTC offset in the form +HHMM | (empty), +0000, -0400, | \(6) | +| | or -HHMM (empty string if the | +1030 | | +| | the object is naive). | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%Z`` | Time zone name (empty string | (empty), UTC, EST, CST | | +| | if the object is naive). | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%j`` | Day of the year as a | 001, 002, ..., 366 | | +| | zero-padded decimal number. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%U`` | Week number of the year | 00, 01, ..., 53 | \(7) | +| | (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. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%W`` | Week number of the year | 00, 01, ..., 53 | \(7) | +| | (Monday as the first day of | | | +| | the week) as a decimal number. | | | +| | All days in a new year | | | +| | preceding the first Monday | | | +| | are considered to be in | | | +| | week 0. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%c`` | Locale's appropriate date and || Tue Aug 16 21:30:00 | \(1) | +| | time representation. | 1988 (en_US); | | +| | || Di 16 Aug 21:30:00 | | +| | | 1988 (de_DE) | | ++-----------+--------------------------------+------------------------+-------+ +| ``%x`` | Locale's appropriate date || 08/16/88 (None); | \(1) | +| | representation. || 08/16/1988 (en_US); | | +| | || 16.08.1988 (de_DE) | | ++-----------+--------------------------------+------------------------+-------+ +| ``%X`` | Locale's appropriate time || 21:30:00 (en_US); | \(1) | +| | representation. || 21:30:00 (de_DE) | | ++-----------+--------------------------------+------------------------+-------+ +| ``%%`` | A literal ``'%'`` character. | % | | ++-----------+--------------------------------+------------------------+-------+ Notes: (1) - When used with the :meth:`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). + 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 Unicode characters encoded using the locale's default encoding (for + example, if the current locale is ``js_JP``, the default encoding could be + any one of ``eucJP``, ``SJIS``, or ``utf-8``; use :meth:`locale.getlocale` + to determine the current locale's encoding). (2) - When used with the :meth:`strptime` method, the ``%p`` directive only affects - the output hour field if the ``%I`` directive is used to parse the hour. - -(3) - Unlike :mod:`time` module, :mod:`datetime` module does not support - leap seconds. - -(4) - When used with the :meth:`strptime` method, ``%U`` and ``%W`` are only used in - calculations when the day of the week and the year are specified. - -(5) - The :meth:`strptime` method can - parse years in the full [1, 9999] range, but years < 1000 must be - zero-filled to 4-digit width. + The :meth:`strptime` method can parse years in the full [1, 9999] range, but + years < 1000 must be zero-filled to 4-digit width. .. versionchanged:: 3.2 In previous versions, :meth:`strftime` method was restricted to @@ -1917,14 +1911,48 @@ Notes: In version 3.2, :meth:`strftime` method was restricted to years >= 1000. +(3) + When used with the :meth:`strptime` method, the ``%p`` directive only affects + the output hour field if the ``%I`` directive is used to parse the hour. + +(4) + Unlike the :mod:`time` module, the :mod:`datetime` module does not support + leap seconds. + +(5) + When used with the :meth:`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) - For example, if :meth:`utcoffset` returns ``timedelta(hours=-3, minutes=-30)``, - ``%z`` is replaced with the string ``'-0330'``. + For a naive object, the ``%z`` and ``%Z`` format codes are replaced by empty + strings. -.. versionchanged:: 3.2 - When the ``%z`` directive is provided to the :meth:`strptime` method, an - aware :class:`.datetime` object will be produced. The ``tzinfo`` of the - result will be set to a :class:`timezone` instance. + For an aware object: + + ``%z`` + :meth:`utcoffset` is transformed into a 5-character string of the form + +HHMM or -HHMM, where HH is a 2-digit string giving the number of UTC + offset hours, and MM is a 2-digit string giving the number of UTC offset + minutes. For example, if :meth:`utcoffset` returns + ``timedelta(hours=-3, minutes=-30)``, ``%z`` is replaced with the string + ``'-0330'``. + + ``%Z`` + If :meth:`tzname` returns ``None``, ``%Z`` is replaced by an empty + string. Otherwise ``%Z`` is replaced by the returned value, which must + be a string. + + .. versionchanged:: 3.2 + When the ``%z`` directive is provided to the :meth:`strptime` method, an + aware :class:`.datetime` object will be produced. The ``tzinfo`` of the + result will be set to a :class:`timezone` instance. + +(7) + When used with the :meth:`strptime` method, ``%U`` and ``%W`` are only used + in calculations when the day of the week and the year are specified. .. rubric:: Footnotes |