[Python-checkins] cpython (merge 2.7 -> 2.7): Issue #17701: Improving strftime documentation
david.wolever
python-checkins at python.org
Mon Aug 12 21:51:34 CEST 2013
http://hg.python.org/cpython/rev/adbc9789a5e4
changeset: 85139:adbc9789a5e4
branch: 2.7
parent: 85121:9ddc63c039ba
parent: 85138:0f4d971b0cee
user: David Wolever <david at wolever.net>
date: Mon Aug 12 15:50:10 2013 -0400
summary:
Issue #17701: Improving strftime documentation
files:
Doc/library/datetime.rst | 260 ++++++++++++++------------
Misc/NEWS | 1 +
2 files changed, 142 insertions(+), 119 deletions(-)
diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
--- a/Doc/library/datetime.rst
+++ b/Doc/library/datetime.rst
@@ -551,8 +551,9 @@
.. 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 section
+ :ref:`strftime-strptime-behavior`.
.. method:: date.__format__(format)
@@ -730,7 +731,8 @@
*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 section
+ :ref:`strftime-strptime-behavior`.
.. versionadded:: 2.5
@@ -1050,7 +1052,8 @@
.. 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 section
+ :ref:`strftime-strptime-behavior`.
.. method:: datetime.__format__(format)
@@ -1283,7 +1286,8 @@
.. method:: time.strftime(format)
Return a string representing the time, controlled by an explicit format string.
- See section :ref:`strftime-strptime-behavior`.
+ For a complete list of formatting directives, see section
+ :ref:`strftime-strptime-behavior`.
.. method:: time.__format__(format)
@@ -1597,27 +1601,6 @@
microseconds should not be used, as :class:`date` objects have no such
values. If they're used anyway, ``0`` is substituted for them.
-.. versionadded:: 2.6
- :class:`.time` and :class:`.datetime` objects support a ``%f`` format code
- which expands to the number of microseconds in the object, zero-padded on
- the left to six places.
-
-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.
@@ -1630,99 +1613,115 @@
The exact range of years for which :meth:`strftime` works also varies across
platforms. Regardless of platform, years before 1900 cannot be used.
-+-----------+--------------------------------+-------+
-| 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) |
-| | [00,61]. | |
-+-----------+--------------------------------+-------+
-| ``%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 | |
-| | number. | |
-+-----------+--------------------------------+-------+
-| ``%z`` | UTC offset in the form +HHMM | \(5) |
-| | 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 | 1970, 1988, 2001, 2013 | |
+| | number. | | |
++-----------+--------------------------------+------------------------+-------+
+| ``%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) | \(2) |
++-----------+--------------------------------+------------------------+-------+
+| ``%M`` | Minute as a zero-padded | 00, 01, ..., 59 | |
+| | decimal number. | | |
++-----------+--------------------------------+------------------------+-------+
+| ``%S`` | Second as a zero-padded | 00, 01, ..., 61 | \(3) |
+| | decimal number. | | |
++-----------+--------------------------------+------------------------+-------+
+| ``%f`` | Microsecond as a decimal | 000000, 000001, ..., | \(4) |
+| | number, zero-padded on the | 999999 | |
+| | left. | | |
++-----------+--------------------------------+------------------------+-------+
+| ``%z`` | UTC offset in the form +HHMM | (empty), +0000, -0400, | \(5) |
+| | 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 | \(6) |
+| | (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 | \(6) |
+| | (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
@@ -1737,12 +1736,35 @@
produce them in :func:`strftime` output.
(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.
+ ``%f`` is an extension to the set of format characters in the C standard
+ (but implemented separately in datetime objects, and therefore always
+ available). When used with the :meth:`strptime` method, the ``%f``
+ directive accepts from one to six digits and zero pads on the right.
+
+ .. versionadded:: 2.6
(5)
- 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.
+
+ 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.
+
+(6)
+ 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
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -164,6 +164,7 @@
Documentation
-------------
+- Issue #17701: Improving strftime documentation.
- Issue #17844: Refactor a documentation of Python specific encodings.
Add links to encoders and decoders for binary-to-binary codecs.
--
Repository URL: http://hg.python.org/cpython
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