cmlenz@2: .. -*- mode: rst; encoding: utf-8 -*-
cmlenz@2: 
cmlenz@2: ==========================
cmlenz@2: Number and Date Formatting
cmlenz@2: ==========================
cmlenz@2: 
cmlenz@2: 
cmlenz@2: .. contents:: Contents
cmlenz@2:    :depth: 2
cmlenz@2: .. sectnum::
cmlenz@2: 
cmlenz@2: 
cmlenz@18: Date Formatting
cmlenz@18: ===============
cmlenz@18: 
cmlenz@18: When working with date and time information in Python, you commonly use the
cmlenz@18: classes ``date``, ``datetime`` and/or ``time`` from the `datetime package`_.
cmlenz@18: Babel provides functions for locale-specific formatting of those objects in its
cmlenz@18: ``dates`` module::
cmlenz@18: 
cmlenz@18:     >>> from datetime import date, datetime, time
cmlenz@18:     >>> from babel.dates import format_date, format_datetime, format_time
cmlenz@18: 
cmlenz@18:     >>> d = date(2007, 4, 1)
cmlenz@18:     >>> format_date(d, locale='en')
cmlenz@18:     u'Apr 1, 2007'
cmlenz@18:     >>> format_date(d, locale='de_DE')
cmlenz@18:     u'01.04.2007'
cmlenz@18: 
cmlenz@18: As this example demonstrates, Babel will automatically choose a date format
cmlenz@18: that is appropriate for the requested locale.
cmlenz@18: 
cmlenz@18: The ``format_*()`` functions also accept an optional ``format`` argument, which
cmlenz@18: allows you to choose between one of four format variations:
cmlenz@18: 
cmlenz@18:  * ``short``,
cmlenz@18:  * ``medium`` (the default),
cmlenz@18:  * ``long`` (the default), and
cmlenz@18:  * ``full`` (the default).
cmlenz@18: 
cmlenz@18: For example::
cmlenz@18: 
cmlenz@18:     >>> format_date(d, format='short', locale='en')
cmlenz@18:     u'4/1/07'
cmlenz@18:     >>> format_date(d, format='long', locale='en')
cmlenz@18:     u'April 1, 2007'
cmlenz@18:     >>> format_date(d, format='full', locale='en')
cmlenz@18:     u'Sunday, April 1, 2007'
cmlenz@18: 
cmlenz@18: .. _`datetime package`: http://docs.python.org/lib/module-datetime.html
cmlenz@18: 
cmlenz@18: 
cmlenz@18: Pattern Syntax
cmlenz@18: --------------
cmlenz@18: 
cmlenz@18: While Babel makes it simple to use the appropriate date/time format for a given
cmlenz@18: locale, you can also force it to use custom patterns. Note that Babel uses
cmlenz@18: different patterns for specifying number and date formats compared to the
cmlenz@18: Python equivalents (such as ``time.strftime()``), which have mostly been
cmlenz@18: inherited from C and POSIX. The patterns used in Babel are based on the
cmlenz@18: `Locale Data Markup Language specification`_ (LDML), which defines them as
cmlenz@18: follows:
cmlenz@18: 
cmlenz@18:     A date/time pattern is a string of characters, where specific strings of
cmlenz@18:     characters are replaced with date and time data from a calendar when formatting
cmlenz@18:     or used to generate data for a calendar when parsing. […]
cmlenz@18: 
cmlenz@18:     Characters may be used multiple times. For example, if ``y`` is used for the
cmlenz@18:     year, ``yy`` might produce "99", whereas ``yyyy`` produces "1999". For most
cmlenz@18:     numerical fields, the number of characters specifies the field width. For
cmlenz@18:     example, if ``h`` is the hour, ``h`` might produce "5", but ``hh`` produces
cmlenz@18:     "05". For some characters, the count specifies whether an abbreviated or full
cmlenz@18:     form should be used […]
cmlenz@18: 
cmlenz@18:     Two single quotes represent a literal single quote, either inside or outside
cmlenz@18:     single quotes. Text within single quotes is not interpreted in any way (except
cmlenz@18:     for two adjacent single quotes).
cmlenz@18: 
cmlenz@18: For example::
cmlenz@18: 
cmlenz@18:     >>> d = date(2007, 4, 1)
cmlenz@18:     >>> format_date(d, "EEE, MMM d, ''yy", locale='en')
cmlenz@18:     u"Sun, Apr 1, '07"
cmlenz@18:     >>> format_date(d, "EEEE, d.M.yyyy", locale='de')
cmlenz@18:     u'Sonntag, 1.4.2007'
cmlenz@18: 
cmlenz@18:     >>> t = time(15, 30)
cmlenz@18:     >>> format_time(t, "hh 'o''clock' a", locale='en')
cmlenz@18:     u"03 o'clock PM"
cmlenz@18:     >>> format_time(t, 'H:mm a', locale='de')
cmlenz@18:     u'15:30 nachm.'
cmlenz@18: 
cmlenz@18:     >>> dt = datetime(2007, 4, 1, 15, 30)
cmlenz@18:     >>> format_datetime(dt, "yyyyy.MMMM.dd GGG hh:mm a", locale='en')
cmlenz@18:     u'02007.April.01 AD 03:30 PM'
cmlenz@18: 
cmlenz@18: The syntax for custom datetime format patterns is described in detail in the
cmlenz@18: the `Locale Data Markup Language specification`_. The following table is just a
cmlenz@18: relatively brief overview.
cmlenz@18: 
cmlenz@18:  .. _`Locale Data Markup Language specification`: http://unicode.org/reports/tr35/#Date_Format_Patterns
cmlenz@18: 
cmlenz@18: -----------
cmlenz@18: Date Fields
cmlenz@18: -----------
cmlenz@18: 
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Field    | Symbol | Description                                            |
cmlenz@18:   +==========+========+========================================================+
cmlenz@18:   | Era      | ``G``  | Replaced with the era string for the current date. One |
cmlenz@18:   |          |        | to three letters for the abbreviated form, four        |
cmlenz@18:   |          |        | lettersfor the long form, five for the narrow form     |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Year     | ``y``  | Replaced by the year. Normally the length specifies    |
cmlenz@18:   |          |        | the padding, but for two letters it also specifies the |
cmlenz@18:   |          |        | maximum length.                                        |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``Y``  | Same as ``y`` but uses the ISO year-week calendar.     |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``u``  | ??                                                     |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Quarter  | ``Q``  | Use one or two for the numerical quarter, three for    |
cmlenz@18:   |          |        | the abbreviation, or four for the full name.           |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``q``  | Use one or two for the numerical quarter, three for    |
cmlenz@18:   |          |        | the abbreviation, or four for the full name.           |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Month    | ``M``  | Use one or two for the numerical month, three for the  |
cmlenz@18:   |          |        | abbreviation, or four for the full name, or five for   |
cmlenz@18:   |          |        | the narrow name.                                       |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``L``  | Use one or two for the numerical month, three for the  |
cmlenz@18:   |          |        | abbreviation, or four for the full name, or 5 for the  |
cmlenz@18:   |          |        | narrow name.                                           |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Week     | ``w``  | Week of year.                                          |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``W``  | Week of month.                                         |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Day      | ``d``  | Day of month.                                          |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``D``  | Day of year.                                           |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``F``  | Day of week in month.                                  |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``g``  | ??                                                     |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Week day | ``E``  | Day of week. Use one through three letters for the     |
cmlenz@18:   |          |        | short day, or four for the full name, or five for the  |
cmlenz@18:   |          |        | narrow name.                                           |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``e``  | Local day of week. Same as E except adds a numeric     |
cmlenz@18:   |          |        | value that will depend on the local starting day of    |
cmlenz@18:   |          |        | the week, using one or two letters.                    |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``c``  | ??                                                     |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18: 
cmlenz@18: -----------
cmlenz@18: Time Fields
cmlenz@18: -----------
cmlenz@18: 
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Field    | Symbol | Description                                            |
cmlenz@18:   +==========+========+========================================================+
cmlenz@18:   | Period   | ``a``  | AM or PM                                               |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Hour     | ``h``  | Hour [1-12].                                           |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``H``  | Hour [0-23].                                           |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``K``  | Hour [0-11].                                           |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``k``  | Hour [1-24].                                           |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Minute   | ``m``  | Use one or two for zero places padding.                |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18:   | Second   | ``s``  | Use one or two for zero places padding.                |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``S``  | Fractional second, rounds to the count of letters.     |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``A``  | Milliseconds in day.                                   |
cmlenz@18:   +----------+--------+--------------------------------------------------------+ 
cmlenz@18:   | Timezone | ``z``  | Use one to three letters for the short timezone or     |
cmlenz@18:   |          |        | four for the full name.                                |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``Z``  | Use one to three letters for RFC 822, four letters for |
cmlenz@18:   |          |        | GMT format.                                            |
cmlenz@18:   |          +--------+--------------------------------------------------------+
cmlenz@18:   |          | ``v``  | Use one letter for short wall (generic) time, four for |
cmlenz@18:   |          |        | long wall time.                                        |
cmlenz@18:   +----------+--------+--------------------------------------------------------+
cmlenz@18: 
cmlenz@18: 
cmlenz@18: Parsing Dates
cmlenz@18: -------------
cmlenz@18: 
cmlenz@18: Babel can also parse date and time information in a locale-sensitive manner::
cmlenz@18: 
cmlenz@18:     >>> from babel.dates import parse_date, parse_datetime, parse_time
cmlenz@18: 
cmlenz@18: 
cmlenz@18: Number Formatting
cmlenz@18: =================
cmlenz@18: 
cmlenz@18: 
cmlenz@18: Pattern Syntax
cmlenz@18: --------------
cmlenz@18: 
cmlenz@18: 
cmlenz@18: Parsing Numbers
cmlenz@18: ---------------