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Edit File: dates.py
""" babel.dates ~~~~~~~~~~~ Locale dependent formatting and parsing of dates and times. The default locale for the functions in this module is determined by the following environment variables, in that order: * ``LC_TIME``, * ``LC_ALL``, and * ``LANG`` :copyright: (c) 2013-2022 by the Babel Team. :license: BSD, see LICENSE for more details. """ import re import warnings import pytz as _pytz from datetime import date, datetime, time, timedelta from bisect import bisect_right from babel.core import default_locale, get_global, Locale from babel.util import UTC, LOCALTZ # "If a given short metazone form is known NOT to be understood in a given # locale and the parent locale has this value such that it would normally # be inherited, the inheritance of this value can be explicitly disabled by # use of the 'no inheritance marker' as the value, which is 3 simultaneous [sic] # empty set characters ( U+2205 )." # - https://www.unicode.org/reports/tr35/tr35-dates.html#Metazone_Names NO_INHERITANCE_MARKER = u'\u2205\u2205\u2205' LC_TIME = default_locale('LC_TIME') # Aliases for use in scopes where the modules are shadowed by local variables date_ = date datetime_ = datetime time_ = time def _get_dt_and_tzinfo(dt_or_tzinfo): """ Parse a `dt_or_tzinfo` value into a datetime and a tzinfo. See the docs for this function's callers for semantics. :rtype: tuple[datetime, tzinfo] """ if dt_or_tzinfo is None: dt = datetime.now() tzinfo = LOCALTZ elif isinstance(dt_or_tzinfo, str): dt = None tzinfo = get_timezone(dt_or_tzinfo) elif isinstance(dt_or_tzinfo, int): dt = None tzinfo = UTC elif isinstance(dt_or_tzinfo, (datetime, time)): dt = _get_datetime(dt_or_tzinfo) if dt.tzinfo is not None: tzinfo = dt.tzinfo else: tzinfo = UTC else: dt = None tzinfo = dt_or_tzinfo return dt, tzinfo def _get_tz_name(dt_or_tzinfo): """ Get the timezone name out of a time, datetime, or tzinfo object. :rtype: str """ dt, tzinfo = _get_dt_and_tzinfo(dt_or_tzinfo) if hasattr(tzinfo, 'zone'): # pytz object return tzinfo.zone elif hasattr(tzinfo, 'key') and tzinfo.key is not None: # ZoneInfo object return tzinfo.key else: return tzinfo.tzname(dt or datetime.utcnow()) def _get_datetime(instant): """ Get a datetime out of an "instant" (date, time, datetime, number). .. warning:: The return values of this function may depend on the system clock. If the instant is None, the current moment is used. If the instant is a time, it's augmented with today's date. Dates are converted to naive datetimes with midnight as the time component. >>> _get_datetime(date(2015, 1, 1)) datetime.datetime(2015, 1, 1, 0, 0) UNIX timestamps are converted to datetimes. >>> _get_datetime(1400000000) datetime.datetime(2014, 5, 13, 16, 53, 20) Other values are passed through as-is. >>> x = datetime(2015, 1, 1) >>> _get_datetime(x) is x True :param instant: date, time, datetime, integer, float or None :type instant: date|time|datetime|int|float|None :return: a datetime :rtype: datetime """ if instant is None: return datetime_.utcnow() elif isinstance(instant, int) or isinstance(instant, float): return datetime_.utcfromtimestamp(instant) elif isinstance(instant, time): return datetime_.combine(date.today(), instant) elif isinstance(instant, date) and not isinstance(instant, datetime): return datetime_.combine(instant, time()) # TODO (3.x): Add an assertion/type check for this fallthrough branch: return instant def _ensure_datetime_tzinfo(datetime, tzinfo=None): """ Ensure the datetime passed has an attached tzinfo. If the datetime is tz-naive to begin with, UTC is attached. If a tzinfo is passed in, the datetime is normalized to that timezone. >>> _ensure_datetime_tzinfo(datetime(2015, 1, 1)).tzinfo.zone 'UTC' >>> tz = get_timezone("Europe/Stockholm") >>> _ensure_datetime_tzinfo(datetime(2015, 1, 1, 13, 15, tzinfo=UTC), tzinfo=tz).hour 14 :param datetime: Datetime to augment. :param tzinfo: Optional tznfo. :return: datetime with tzinfo :rtype: datetime """ if datetime.tzinfo is None: datetime = datetime.replace(tzinfo=UTC) if tzinfo is not None: datetime = datetime.astimezone(get_timezone(tzinfo)) if hasattr(tzinfo, 'normalize'): # pytz datetime = tzinfo.normalize(datetime) return datetime def _get_time(time, tzinfo=None): """ Get a timezoned time from a given instant. .. warning:: The return values of this function may depend on the system clock. :param time: time, datetime or None :rtype: time """ if time is None: time = datetime.utcnow() elif isinstance(time, (int, float)): time = datetime.utcfromtimestamp(time) if time.tzinfo is None: time = time.replace(tzinfo=UTC) if isinstance(time, datetime): if tzinfo is not None: time = time.astimezone(tzinfo) if hasattr(tzinfo, 'normalize'): # pytz time = tzinfo.normalize(time) time = time.timetz() elif tzinfo is not None: time = time.replace(tzinfo=tzinfo) return time def get_timezone(zone=None): """Looks up a timezone by name and returns it. The timezone object returned comes from ``pytz`` and corresponds to the `tzinfo` interface and can be used with all of the functions of Babel that operate with dates. If a timezone is not known a :exc:`LookupError` is raised. If `zone` is ``None`` a local zone object is returned. :param zone: the name of the timezone to look up. If a timezone object itself is passed in, mit's returned unchanged. """ if zone is None: return LOCALTZ if not isinstance(zone, str): return zone try: return _pytz.timezone(zone) except _pytz.UnknownTimeZoneError: raise LookupError('Unknown timezone %s' % zone) def get_next_timezone_transition(zone=None, dt=None): """Given a timezone it will return a :class:`TimezoneTransition` object that holds the information about the next timezone transition that's going to happen. For instance this can be used to detect when the next DST change is going to happen and how it looks like. The transition is calculated relative to the given datetime object. The next transition that follows the date is used. If a transition cannot be found the return value will be `None`. Transition information can only be provided for timezones returned by the :func:`get_timezone` function. This function is pending deprecation with no replacement planned in the Babel library. :param zone: the timezone for which the transition should be looked up. If not provided the local timezone is used. :param dt: the date after which the next transition should be found. If not given the current time is assumed. """ warnings.warn( "get_next_timezone_transition() is deprecated and will be " "removed in the next version of Babel. " "Please see https://github.com/python-babel/babel/issues/716 " "for discussion.", category=DeprecationWarning, ) zone = get_timezone(zone) dt = _get_datetime(dt).replace(tzinfo=None) if not hasattr(zone, '_utc_transition_times'): raise TypeError('Given timezone does not have UTC transition ' 'times. This can happen because the operating ' 'system fallback local timezone is used or a ' 'custom timezone object') try: idx = max(0, bisect_right(zone._utc_transition_times, dt)) old_trans = zone._transition_info[idx - 1] new_trans = zone._transition_info[idx] old_tz = zone._tzinfos[old_trans] new_tz = zone._tzinfos[new_trans] except (LookupError, ValueError): return None return TimezoneTransition( activates=zone._utc_transition_times[idx], from_tzinfo=old_tz, to_tzinfo=new_tz, reference_date=dt ) class TimezoneTransition: """A helper object that represents the return value from :func:`get_next_timezone_transition`. This class is pending deprecation with no replacement planned in the Babel library. :field activates: The time of the activation of the timezone transition in UTC. :field from_tzinfo: The timezone from where the transition starts. :field to_tzinfo: The timezone for after the transition. :field reference_date: The reference date that was provided. This is the `dt` parameter to the :func:`get_next_timezone_transition`. """ def __init__(self, activates, from_tzinfo, to_tzinfo, reference_date=None): warnings.warn( "TimezoneTransition is deprecated and will be " "removed in the next version of Babel. " "Please see https://github.com/python-babel/babel/issues/716 " "for discussion.", category=DeprecationWarning, ) self.activates = activates self.from_tzinfo = from_tzinfo self.to_tzinfo = to_tzinfo self.reference_date = reference_date @property def from_tz(self): """The name of the timezone before the transition.""" return self.from_tzinfo._tzname @property def to_tz(self): """The name of the timezone after the transition.""" return self.to_tzinfo._tzname @property def from_offset(self): """The UTC offset in seconds before the transition.""" return int(self.from_tzinfo._utcoffset.total_seconds()) @property def to_offset(self): """The UTC offset in seconds after the transition.""" return int(self.to_tzinfo._utcoffset.total_seconds()) def __repr__(self): return '<TimezoneTransition %s -> %s (%s)>' % ( self.from_tz, self.to_tz, self.activates, ) def get_period_names(width='wide', context='stand-alone', locale=LC_TIME): """Return the names for day periods (AM/PM) used by the locale. >>> get_period_names(locale='en_US')['am'] u'AM' :param width: the width to use, one of "abbreviated", "narrow", or "wide" :param context: the context, either "format" or "stand-alone" :param locale: the `Locale` object, or a locale string """ return Locale.parse(locale).day_periods[context][width] def get_day_names(width='wide', context='format', locale=LC_TIME): """Return the day names used by the locale for the specified format. >>> get_day_names('wide', locale='en_US')[1] u'Tuesday' >>> get_day_names('short', locale='en_US')[1] u'Tu' >>> get_day_names('abbreviated', locale='es')[1] u'mar' >>> get_day_names('narrow', context='stand-alone', locale='de_DE')[1] u'D' :param width: the width to use, one of "wide", "abbreviated", "short" or "narrow" :param context: the context, either "format" or "stand-alone" :param locale: the `Locale` object, or a locale string """ return Locale.parse(locale).days[context][width] def get_month_names(width='wide', context='format', locale=LC_TIME): """Return the month names used by the locale for the specified format. >>> get_month_names('wide', locale='en_US')[1] u'January' >>> get_month_names('abbreviated', locale='es')[1] u'ene' >>> get_month_names('narrow', context='stand-alone', locale='de_DE')[1] u'J' :param width: the width to use, one of "wide", "abbreviated", or "narrow" :param context: the context, either "format" or "stand-alone" :param locale: the `Locale` object, or a locale string """ return Locale.parse(locale).months[context][width] def get_quarter_names(width='wide', context='format', locale=LC_TIME): """Return the quarter names used by the locale for the specified format. >>> get_quarter_names('wide', locale='en_US')[1] u'1st quarter' >>> get_quarter_names('abbreviated', locale='de_DE')[1] u'Q1' >>> get_quarter_names('narrow', locale='de_DE')[1] u'1' :param width: the width to use, one of "wide", "abbreviated", or "narrow" :param context: the context, either "format" or "stand-alone" :param locale: the `Locale` object, or a locale string """ return Locale.parse(locale).quarters[context][width] def get_era_names(width='wide', locale=LC_TIME): """Return the era names used by the locale for the specified format. >>> get_era_names('wide', locale='en_US')[1] u'Anno Domini' >>> get_era_names('abbreviated', locale='de_DE')[1] u'n. Chr.' :param width: the width to use, either "wide", "abbreviated", or "narrow" :param locale: the `Locale` object, or a locale string """ return Locale.parse(locale).eras[width] def get_date_format(format='medium', locale=LC_TIME): """Return the date formatting patterns used by the locale for the specified format. >>> get_date_format(locale='en_US') <DateTimePattern u'MMM d, y'> >>> get_date_format('full', locale='de_DE') <DateTimePattern u'EEEE, d. MMMM y'> :param format: the format to use, one of "full", "long", "medium", or "short" :param locale: the `Locale` object, or a locale string """ return Locale.parse(locale).date_formats[format] def get_datetime_format(format='medium', locale=LC_TIME): """Return the datetime formatting patterns used by the locale for the specified format. >>> get_datetime_format(locale='en_US') u'{1}, {0}' :param format: the format to use, one of "full", "long", "medium", or "short" :param locale: the `Locale` object, or a locale string """ patterns = Locale.parse(locale).datetime_formats if format not in patterns: format = None return patterns[format] def get_time_format(format='medium', locale=LC_TIME): """Return the time formatting patterns used by the locale for the specified format. >>> get_time_format(locale='en_US') <DateTimePattern u'h:mm:ss a'> >>> get_time_format('full', locale='de_DE') <DateTimePattern u'HH:mm:ss zzzz'> :param format: the format to use, one of "full", "long", "medium", or "short" :param locale: the `Locale` object, or a locale string """ return Locale.parse(locale).time_formats[format] def get_timezone_gmt(datetime=None, width='long', locale=LC_TIME, return_z=False): """Return the timezone associated with the given `datetime` object formatted as string indicating the offset from GMT. >>> dt = datetime(2007, 4, 1, 15, 30) >>> get_timezone_gmt(dt, locale='en') u'GMT+00:00' >>> get_timezone_gmt(dt, locale='en', return_z=True) 'Z' >>> get_timezone_gmt(dt, locale='en', width='iso8601_short') u'+00' >>> tz = get_timezone('America/Los_Angeles') >>> dt = tz.localize(datetime(2007, 4, 1, 15, 30)) >>> get_timezone_gmt(dt, locale='en') u'GMT-07:00' >>> get_timezone_gmt(dt, 'short', locale='en') u'-0700' >>> get_timezone_gmt(dt, locale='en', width='iso8601_short') u'-07' The long format depends on the locale, for example in France the acronym UTC string is used instead of GMT: >>> get_timezone_gmt(dt, 'long', locale='fr_FR') u'UTC-07:00' .. versionadded:: 0.9 :param datetime: the ``datetime`` object; if `None`, the current date and time in UTC is used :param width: either "long" or "short" or "iso8601" or "iso8601_short" :param locale: the `Locale` object, or a locale string :param return_z: True or False; Function returns indicator "Z" when local time offset is 0 """ datetime = _ensure_datetime_tzinfo(_get_datetime(datetime)) locale = Locale.parse(locale) offset = datetime.tzinfo.utcoffset(datetime) seconds = offset.days * 24 * 60 * 60 + offset.seconds hours, seconds = divmod(seconds, 3600) if return_z and hours == 0 and seconds == 0: return 'Z' elif seconds == 0 and width == 'iso8601_short': return u'%+03d' % hours elif width == 'short' or width == 'iso8601_short': pattern = u'%+03d%02d' elif width == 'iso8601': pattern = u'%+03d:%02d' else: pattern = locale.zone_formats['gmt'] % '%+03d:%02d' return pattern % (hours, seconds // 60) def get_timezone_location(dt_or_tzinfo=None, locale=LC_TIME, return_city=False): u"""Return a representation of the given timezone using "location format". The result depends on both the local display name of the country and the city associated with the time zone: >>> tz = get_timezone('America/St_Johns') >>> print(get_timezone_location(tz, locale='de_DE')) Kanada (St. John’s) Zeit >>> print(get_timezone_location(tz, locale='en')) Canada (St. John’s) Time >>> print(get_timezone_location(tz, locale='en', return_city=True)) St. John’s >>> tz = get_timezone('America/Mexico_City') >>> get_timezone_location(tz, locale='de_DE') u'Mexiko (Mexiko-Stadt) Zeit' If the timezone is associated with a country that uses only a single timezone, just the localized country name is returned: >>> tz = get_timezone('Europe/Berlin') >>> get_timezone_name(tz, locale='de_DE') u'Mitteleurop\\xe4ische Zeit' .. versionadded:: 0.9 :param dt_or_tzinfo: the ``datetime`` or ``tzinfo`` object that determines the timezone; if `None`, the current date and time in UTC is assumed :param locale: the `Locale` object, or a locale string :param return_city: True or False, if True then return exemplar city (location) for the time zone :return: the localized timezone name using location format """ locale = Locale.parse(locale) zone = _get_tz_name(dt_or_tzinfo) # Get the canonical time-zone code zone = get_global('zone_aliases').get(zone, zone) info = locale.time_zones.get(zone, {}) # Otherwise, if there is only one timezone for the country, return the # localized country name region_format = locale.zone_formats['region'] territory = get_global('zone_territories').get(zone) if territory not in locale.territories: territory = 'ZZ' # invalid/unknown territory_name = locale.territories[territory] if not return_city and territory and len(get_global('territory_zones').get(territory, [])) == 1: return region_format % territory_name # Otherwise, include the city in the output fallback_format = locale.zone_formats['fallback'] if 'city' in info: city_name = info['city'] else: metazone = get_global('meta_zones').get(zone) metazone_info = locale.meta_zones.get(metazone, {}) if 'city' in metazone_info: city_name = metazone_info['city'] elif '/' in zone: city_name = zone.split('/', 1)[1].replace('_', ' ') else: city_name = zone.replace('_', ' ') if return_city: return city_name return region_format % (fallback_format % { '0': city_name, '1': territory_name }) def get_timezone_name(dt_or_tzinfo=None, width='long', uncommon=False, locale=LC_TIME, zone_variant=None, return_zone=False): r"""Return the localized display name for the given timezone. The timezone may be specified using a ``datetime`` or `tzinfo` object. >>> dt = time(15, 30, tzinfo=get_timezone('America/Los_Angeles')) >>> get_timezone_name(dt, locale='en_US') u'Pacific Standard Time' >>> get_timezone_name(dt, locale='en_US', return_zone=True) 'America/Los_Angeles' >>> get_timezone_name(dt, width='short', locale='en_US') u'PST' If this function gets passed only a `tzinfo` object and no concrete `datetime`, the returned display name is indenpendent of daylight savings time. This can be used for example for selecting timezones, or to set the time of events that recur across DST changes: >>> tz = get_timezone('America/Los_Angeles') >>> get_timezone_name(tz, locale='en_US') u'Pacific Time' >>> get_timezone_name(tz, 'short', locale='en_US') u'PT' If no localized display name for the timezone is available, and the timezone is associated with a country that uses only a single timezone, the name of that country is returned, formatted according to the locale: >>> tz = get_timezone('Europe/Berlin') >>> get_timezone_name(tz, locale='de_DE') u'Mitteleurop\xe4ische Zeit' >>> get_timezone_name(tz, locale='pt_BR') u'Hor\xe1rio da Europa Central' On the other hand, if the country uses multiple timezones, the city is also included in the representation: >>> tz = get_timezone('America/St_Johns') >>> get_timezone_name(tz, locale='de_DE') u'Neufundland-Zeit' Note that short format is currently not supported for all timezones and all locales. This is partially because not every timezone has a short code in every locale. In that case it currently falls back to the long format. For more information see `LDML Appendix J: Time Zone Display Names <https://www.unicode.org/reports/tr35/#Time_Zone_Fallback>`_ .. versionadded:: 0.9 .. versionchanged:: 1.0 Added `zone_variant` support. :param dt_or_tzinfo: the ``datetime`` or ``tzinfo`` object that determines the timezone; if a ``tzinfo`` object is used, the resulting display name will be generic, i.e. independent of daylight savings time; if `None`, the current date in UTC is assumed :param width: either "long" or "short" :param uncommon: deprecated and ignored :param zone_variant: defines the zone variation to return. By default the variation is defined from the datetime object passed in. If no datetime object is passed in, the ``'generic'`` variation is assumed. The following values are valid: ``'generic'``, ``'daylight'`` and ``'standard'``. :param locale: the `Locale` object, or a locale string :param return_zone: True or False. If true then function returns long time zone ID """ dt, tzinfo = _get_dt_and_tzinfo(dt_or_tzinfo) locale = Locale.parse(locale) zone = _get_tz_name(dt_or_tzinfo) if zone_variant is None: if dt is None: zone_variant = 'generic' else: dst = tzinfo.dst(dt) if dst: zone_variant = 'daylight' else: zone_variant = 'standard' else: if zone_variant not in ('generic', 'standard', 'daylight'): raise ValueError('Invalid zone variation') # Get the canonical time-zone code zone = get_global('zone_aliases').get(zone, zone) if return_zone: return zone info = locale.time_zones.get(zone, {}) # Try explicitly translated zone names first if width in info: if zone_variant in info[width]: return info[width][zone_variant] metazone = get_global('meta_zones').get(zone) if metazone: metazone_info = locale.meta_zones.get(metazone, {}) if width in metazone_info: name = metazone_info[width].get(zone_variant) if width == 'short' and name == NO_INHERITANCE_MARKER: # If the short form is marked no-inheritance, # try to fall back to the long name instead. name = metazone_info.get('long', {}).get(zone_variant) if name: return name # If we have a concrete datetime, we assume that the result can't be # independent of daylight savings time, so we return the GMT offset if dt is not None: return get_timezone_gmt(dt, width=width, locale=locale) return get_timezone_location(dt_or_tzinfo, locale=locale) def format_date(date=None, format='medium', locale=LC_TIME): """Return a date formatted according to the given pattern. >>> d = date(2007, 4, 1) >>> format_date(d, locale='en_US') u'Apr 1, 2007' >>> format_date(d, format='full', locale='de_DE') u'Sonntag, 1. April 2007' If you don't want to use the locale default formats, you can specify a custom date pattern: >>> format_date(d, "EEE, MMM d, ''yy", locale='en') u"Sun, Apr 1, '07" :param date: the ``date`` or ``datetime`` object; if `None`, the current date is used :param format: one of "full", "long", "medium", or "short", or a custom date/time pattern :param locale: a `Locale` object or a locale identifier """ if date is None: date = date_.today() elif isinstance(date, datetime): date = date.date() locale = Locale.parse(locale) if format in ('full', 'long', 'medium', 'short'): format = get_date_format(format, locale=locale) pattern = parse_pattern(format) return pattern.apply(date, locale) def format_datetime(datetime=None, format='medium', tzinfo=None, locale=LC_TIME): r"""Return a date formatted according to the given pattern. >>> dt = datetime(2007, 4, 1, 15, 30) >>> format_datetime(dt, locale='en_US') u'Apr 1, 2007, 3:30:00 PM' For any pattern requiring the display of the time-zone, the third-party ``pytz`` package is needed to explicitly specify the time-zone: >>> format_datetime(dt, 'full', tzinfo=get_timezone('Europe/Paris'), ... locale='fr_FR') u'dimanche 1 avril 2007 \xe0 17:30:00 heure d\u2019\xe9t\xe9 d\u2019Europe centrale' >>> format_datetime(dt, "yyyy.MM.dd G 'at' HH:mm:ss zzz", ... tzinfo=get_timezone('US/Eastern'), locale='en') u'2007.04.01 AD at 11:30:00 EDT' :param datetime: the `datetime` object; if `None`, the current date and time is used :param format: one of "full", "long", "medium", or "short", or a custom date/time pattern :param tzinfo: the timezone to apply to the time for display :param locale: a `Locale` object or a locale identifier """ datetime = _ensure_datetime_tzinfo(_get_datetime(datetime), tzinfo) locale = Locale.parse(locale) if format in ('full', 'long', 'medium', 'short'): return get_datetime_format(format, locale=locale) \ .replace("'", "") \ .replace('{0}', format_time(datetime, format, tzinfo=None, locale=locale)) \ .replace('{1}', format_date(datetime, format, locale=locale)) else: return parse_pattern(format).apply(datetime, locale) def format_time(time=None, format='medium', tzinfo=None, locale=LC_TIME): r"""Return a time formatted according to the given pattern. >>> t = time(15, 30) >>> format_time(t, locale='en_US') u'3:30:00 PM' >>> format_time(t, format='short', locale='de_DE') u'15:30' If you don't want to use the locale default formats, you can specify a custom time pattern: >>> format_time(t, "hh 'o''clock' a", locale='en') u"03 o'clock PM" For any pattern requiring the display of the time-zone a timezone has to be specified explicitly: >>> t = datetime(2007, 4, 1, 15, 30) >>> tzinfo = get_timezone('Europe/Paris') >>> t = tzinfo.localize(t) >>> format_time(t, format='full', tzinfo=tzinfo, locale='fr_FR') u'15:30:00 heure d\u2019\xe9t\xe9 d\u2019Europe centrale' >>> format_time(t, "hh 'o''clock' a, zzzz", tzinfo=get_timezone('US/Eastern'), ... locale='en') u"09 o'clock AM, Eastern Daylight Time" As that example shows, when this function gets passed a ``datetime.datetime`` value, the actual time in the formatted string is adjusted to the timezone specified by the `tzinfo` parameter. If the ``datetime`` is "naive" (i.e. it has no associated timezone information), it is assumed to be in UTC. These timezone calculations are **not** performed if the value is of type ``datetime.time``, as without date information there's no way to determine what a given time would translate to in a different timezone without information about whether daylight savings time is in effect or not. This means that time values are left as-is, and the value of the `tzinfo` parameter is only used to display the timezone name if needed: >>> t = time(15, 30) >>> format_time(t, format='full', tzinfo=get_timezone('Europe/Paris'), ... locale='fr_FR') u'15:30:00 heure normale d\u2019Europe centrale' >>> format_time(t, format='full', tzinfo=get_timezone('US/Eastern'), ... locale='en_US') u'3:30:00 PM Eastern Standard Time' :param time: the ``time`` or ``datetime`` object; if `None`, the current time in UTC is used :param format: one of "full", "long", "medium", or "short", or a custom date/time pattern :param tzinfo: the time-zone to apply to the time for display :param locale: a `Locale` object or a locale identifier """ time = _get_time(time, tzinfo) locale = Locale.parse(locale) if format in ('full', 'long', 'medium', 'short'): format = get_time_format(format, locale=locale) return parse_pattern(format).apply(time, locale) def format_skeleton(skeleton, datetime=None, tzinfo=None, fuzzy=True, locale=LC_TIME): r"""Return a time and/or date formatted according to the given pattern. The skeletons are defined in the CLDR data and provide more flexibility than the simple short/long/medium formats, but are a bit harder to use. The are defined using the date/time symbols without order or punctuation and map to a suitable format for the given locale. >>> t = datetime(2007, 4, 1, 15, 30) >>> format_skeleton('MMMEd', t, locale='fr') u'dim. 1 avr.' >>> format_skeleton('MMMEd', t, locale='en') u'Sun, Apr 1' >>> format_skeleton('yMMd', t, locale='fi') # yMMd is not in the Finnish locale; yMd gets used u'1.4.2007' >>> format_skeleton('yMMd', t, fuzzy=False, locale='fi') # yMMd is not in the Finnish locale, an error is thrown Traceback (most recent call last): ... KeyError: yMMd After the skeleton is resolved to a pattern `format_datetime` is called so all timezone processing etc is the same as for that. :param skeleton: A date time skeleton as defined in the cldr data. :param datetime: the ``time`` or ``datetime`` object; if `None`, the current time in UTC is used :param tzinfo: the time-zone to apply to the time for display :param fuzzy: If the skeleton is not found, allow choosing a skeleton that's close enough to it. :param locale: a `Locale` object or a locale identifier """ locale = Locale.parse(locale) if fuzzy and skeleton not in locale.datetime_skeletons: skeleton = match_skeleton(skeleton, locale.datetime_skeletons) format = locale.datetime_skeletons[skeleton] return format_datetime(datetime, format, tzinfo, locale) TIMEDELTA_UNITS = ( ('year', 3600 * 24 * 365), ('month', 3600 * 24 * 30), ('week', 3600 * 24 * 7), ('day', 3600 * 24), ('hour', 3600), ('minute', 60), ('second', 1) ) def format_timedelta(delta, granularity='second', threshold=.85, add_direction=False, format='long', locale=LC_TIME): """Return a time delta according to the rules of the given locale. >>> format_timedelta(timedelta(weeks=12), locale='en_US') u'3 months' >>> format_timedelta(timedelta(seconds=1), locale='es') u'1 segundo' The granularity parameter can be provided to alter the lowest unit presented, which defaults to a second. >>> format_timedelta(timedelta(hours=3), granularity='day', ... locale='en_US') u'1 day' The threshold parameter can be used to determine at which value the presentation switches to the next higher unit. A higher threshold factor means the presentation will switch later. For example: >>> format_timedelta(timedelta(hours=23), threshold=0.9, locale='en_US') u'1 day' >>> format_timedelta(timedelta(hours=23), threshold=1.1, locale='en_US') u'23 hours' In addition directional information can be provided that informs the user if the date is in the past or in the future: >>> format_timedelta(timedelta(hours=1), add_direction=True, locale='en') u'in 1 hour' >>> format_timedelta(timedelta(hours=-1), add_direction=True, locale='en') u'1 hour ago' The format parameter controls how compact or wide the presentation is: >>> format_timedelta(timedelta(hours=3), format='short', locale='en') u'3 hr' >>> format_timedelta(timedelta(hours=3), format='narrow', locale='en') u'3h' :param delta: a ``timedelta`` object representing the time difference to format, or the delta in seconds as an `int` value :param granularity: determines the smallest unit that should be displayed, the value can be one of "year", "month", "week", "day", "hour", "minute" or "second" :param threshold: factor that determines at which point the presentation switches to the next higher unit :param add_direction: if this flag is set to `True` the return value will include directional information. For instance a positive timedelta will include the information about it being in the future, a negative will be information about the value being in the past. :param format: the format, can be "narrow", "short" or "long". ( "medium" is deprecated, currently converted to "long" to maintain compatibility) :param locale: a `Locale` object or a locale identifier """ if format not in ('narrow', 'short', 'medium', 'long'): raise TypeError('Format must be one of "narrow", "short" or "long"') if format == 'medium': warnings.warn('"medium" value for format param of format_timedelta' ' is deprecated. Use "long" instead', category=DeprecationWarning) format = 'long' if isinstance(delta, timedelta): seconds = int((delta.days * 86400) + delta.seconds) else: seconds = delta locale = Locale.parse(locale) def _iter_patterns(a_unit): if add_direction: unit_rel_patterns = locale._data['date_fields'][a_unit] if seconds >= 0: yield unit_rel_patterns['future'] else: yield unit_rel_patterns['past'] a_unit = 'duration-' + a_unit yield locale._data['unit_patterns'].get(a_unit, {}).get(format) for unit, secs_per_unit in TIMEDELTA_UNITS: value = abs(seconds) / secs_per_unit if value >= threshold or unit == granularity: if unit == granularity and value > 0: value = max(1, value) value = int(round(value)) plural_form = locale.plural_form(value) pattern = None for patterns in _iter_patterns(unit): if patterns is not None: pattern = patterns.get(plural_form) or patterns.get('other') break # This really should not happen if pattern is None: return u'' return pattern.replace('{0}', str(value)) return u'' def _format_fallback_interval(start, end, skeleton, tzinfo, locale): if skeleton in locale.datetime_skeletons: # Use the given skeleton format = lambda dt: format_skeleton(skeleton, dt, tzinfo, locale=locale) elif all((isinstance(d, date) and not isinstance(d, datetime)) for d in (start, end)): # Both are just dates format = lambda dt: format_date(dt, locale=locale) elif all((isinstance(d, time) and not isinstance(d, date)) for d in (start, end)): # Both are times format = lambda dt: format_time(dt, tzinfo=tzinfo, locale=locale) else: format = lambda dt: format_datetime(dt, tzinfo=tzinfo, locale=locale) formatted_start = format(start) formatted_end = format(end) if formatted_start == formatted_end: return format(start) return ( locale.interval_formats.get(None, "{0}-{1}"). replace("{0}", formatted_start). replace("{1}", formatted_end) ) def format_interval(start, end, skeleton=None, tzinfo=None, fuzzy=True, locale=LC_TIME): """ Format an interval between two instants according to the locale's rules. >>> format_interval(date(2016, 1, 15), date(2016, 1, 17), "yMd", locale="fi") u'15.\u201317.1.2016' >>> format_interval(time(12, 12), time(16, 16), "Hm", locale="en_GB") '12:12\u201316:16' >>> format_interval(time(5, 12), time(16, 16), "hm", locale="en_US") '5:12 AM \u2013 4:16 PM' >>> format_interval(time(16, 18), time(16, 24), "Hm", locale="it") '16:18\u201316:24' If the start instant equals the end instant, the interval is formatted like the instant. >>> format_interval(time(16, 18), time(16, 18), "Hm", locale="it") '16:18' Unknown skeletons fall back to "default" formatting. >>> format_interval(date(2015, 1, 1), date(2017, 1, 1), "wzq", locale="ja") '2015/01/01\uff5e2017/01/01' >>> format_interval(time(16, 18), time(16, 24), "xxx", locale="ja") '16:18:00\uff5e16:24:00' >>> format_interval(date(2016, 1, 15), date(2016, 1, 17), "xxx", locale="de") '15.01.2016 \u2013 17.01.2016' :param start: First instant (datetime/date/time) :param end: Second instant (datetime/date/time) :param skeleton: The "skeleton format" to use for formatting. :param tzinfo: tzinfo to use (if none is already attached) :param fuzzy: If the skeleton is not found, allow choosing a skeleton that's close enough to it. :param locale: A locale object or identifier. :return: Formatted interval """ locale = Locale.parse(locale) # NB: The quote comments below are from the algorithm description in # https://www.unicode.org/reports/tr35/tr35-dates.html#intervalFormats # > Look for the intervalFormatItem element that matches the "skeleton", # > starting in the current locale and then following the locale fallback # > chain up to, but not including root. interval_formats = locale.interval_formats if skeleton not in interval_formats or not skeleton: # > If no match was found from the previous step, check what the closest # > match is in the fallback locale chain, as in availableFormats. That # > is, this allows for adjusting the string value field's width, # > including adjusting between "MMM" and "MMMM", and using different # > variants of the same field, such as 'v' and 'z'. if skeleton and fuzzy: skeleton = match_skeleton(skeleton, interval_formats) else: skeleton = None if not skeleton: # Still no match whatsoever? # > Otherwise, format the start and end datetime using the fallback pattern. return _format_fallback_interval(start, end, skeleton, tzinfo, locale) skel_formats = interval_formats[skeleton] if start == end: return format_skeleton(skeleton, start, tzinfo, fuzzy=fuzzy, locale=locale) start = _ensure_datetime_tzinfo(_get_datetime(start), tzinfo=tzinfo) end = _ensure_datetime_tzinfo(_get_datetime(end), tzinfo=tzinfo) start_fmt = DateTimeFormat(start, locale=locale) end_fmt = DateTimeFormat(end, locale=locale) # > If a match is found from previous steps, compute the calendar field # > with the greatest difference between start and end datetime. If there # > is no difference among any of the fields in the pattern, format as a # > single date using availableFormats, and return. for field in PATTERN_CHAR_ORDER: # These are in largest-to-smallest order if field in skel_formats: if start_fmt.extract(field) != end_fmt.extract(field): # > If there is a match, use the pieces of the corresponding pattern to # > format the start and end datetime, as above. return "".join( parse_pattern(pattern).apply(instant, locale) for pattern, instant in zip(skel_formats[field], (start, end)) ) # > Otherwise, format the start and end datetime using the fallback pattern. return _format_fallback_interval(start, end, skeleton, tzinfo, locale) def get_period_id(time, tzinfo=None, type=None, locale=LC_TIME): """ Get the day period ID for a given time. This ID can be used as a key for the period name dictionary. >>> get_period_names(locale="de")[get_period_id(time(7, 42), locale="de")] u'Morgen' >>> get_period_id(time(0), locale="en_US") u'midnight' >>> get_period_id(time(0), type="selection", locale="en_US") u'night1' :param time: The time to inspect. :param tzinfo: The timezone for the time. See ``format_time``. :param type: The period type to use. Either "selection" or None. The selection type is used for selecting among phrases such as “Your email arrived yesterday evening” or “Your email arrived last night”. :param locale: the `Locale` object, or a locale string :return: period ID. Something is always returned -- even if it's just "am" or "pm". """ time = _get_time(time, tzinfo) seconds_past_midnight = int(time.hour * 60 * 60 + time.minute * 60 + time.second) locale = Locale.parse(locale) # The LDML rules state that the rules may not overlap, so iterating in arbitrary # order should be alright, though `at` periods should be preferred. rulesets = locale.day_period_rules.get(type, {}).items() for rule_id, rules in rulesets: for rule in rules: if "at" in rule and rule["at"] == seconds_past_midnight: return rule_id for rule_id, rules in rulesets: for rule in rules: if "from" in rule and "before" in rule: if rule["from"] < rule["before"]: if rule["from"] <= seconds_past_midnight < rule["before"]: return rule_id else: # e.g. from="21:00" before="06:00" if rule["from"] <= seconds_past_midnight < 86400 or \ 0 <= seconds_past_midnight < rule["before"]: return rule_id start_ok = end_ok = False if "from" in rule and seconds_past_midnight >= rule["from"]: start_ok = True if "to" in rule and seconds_past_midnight <= rule["to"]: # This rule type does not exist in the present CLDR data; # excuse the lack of test coverage. end_ok = True if "before" in rule and seconds_past_midnight < rule["before"]: end_ok = True if "after" in rule: raise NotImplementedError("'after' is deprecated as of CLDR 29.") if start_ok and end_ok: return rule_id if seconds_past_midnight < 43200: return "am" else: return "pm" class ParseError(ValueError): pass def parse_date(string, locale=LC_TIME, format='medium'): """Parse a date from a string. This function uses the date format for the locale as a hint to determine the order in which the date fields appear in the string. >>> parse_date('4/1/04', locale='en_US') datetime.date(2004, 4, 1) >>> parse_date('01.04.2004', locale='de_DE') datetime.date(2004, 4, 1) :param string: the string containing the date :param locale: a `Locale` object or a locale identifier :param format: the format to use (see ``get_date_format``) """ numbers = re.findall(r'(\d+)', string) if not numbers: raise ParseError("No numbers were found in input") # TODO: try ISO format first? format_str = get_date_format(format=format, locale=locale).pattern.lower() year_idx = format_str.index('y') month_idx = format_str.index('m') if month_idx < 0: month_idx = format_str.index('l') day_idx = format_str.index('d') indexes = [(year_idx, 'Y'), (month_idx, 'M'), (day_idx, 'D')] indexes.sort() indexes = {item[1]: idx for idx, item in enumerate(indexes)} # FIXME: this currently only supports numbers, but should also support month # names, both in the requested locale, and english year = numbers[indexes['Y']] if len(year) == 2: year = 2000 + int(year) else: year = int(year) month = int(numbers[indexes['M']]) day = int(numbers[indexes['D']]) if month > 12: month, day = day, month return date(year, month, day) def parse_time(string, locale=LC_TIME, format='medium'): """Parse a time from a string. This function uses the time format for the locale as a hint to determine the order in which the time fields appear in the string. >>> parse_time('15:30:00', locale='en_US') datetime.time(15, 30) :param string: the string containing the time :param locale: a `Locale` object or a locale identifier :param format: the format to use (see ``get_time_format``) :return: the parsed time :rtype: `time` """ numbers = re.findall(r'(\d+)', string) if not numbers: raise ParseError("No numbers were found in input") # TODO: try ISO format first? format_str = get_time_format(format=format, locale=locale).pattern.lower() hour_idx = format_str.index('h') if hour_idx < 0: hour_idx = format_str.index('k') min_idx = format_str.index('m') sec_idx = format_str.index('s') indexes = [(hour_idx, 'H'), (min_idx, 'M'), (sec_idx, 'S')] indexes.sort() indexes = {item[1]: idx for idx, item in enumerate(indexes)} # TODO: support time zones # Check if the format specifies a period to be used; # if it does, look for 'pm' to figure out an offset. hour_offset = 0 if 'a' in format_str: if 'pm' in string.lower(): hour_offset = 12 # Parse up to three numbers from the string. minute = second = 0 hour = int(numbers[indexes['H']]) + hour_offset if len(numbers) > 1: minute = int(numbers[indexes['M']]) if len(numbers) > 2: second = int(numbers[indexes['S']]) return time(hour, minute, second) class DateTimePattern: def __init__(self, pattern, format): self.pattern = pattern self.format = format def __repr__(self): return '<%s %r>' % (type(self).__name__, self.pattern) def __unicode__(self): return self.pattern def __str__(self): pat = self.pattern return pat def __mod__(self, other): if type(other) is not DateTimeFormat: return NotImplemented return self.format % other def apply(self, datetime, locale): return self % DateTimeFormat(datetime, locale) class DateTimeFormat: def __init__(self, value, locale): assert isinstance(value, (date, datetime, time)) if isinstance(value, (datetime, time)) and value.tzinfo is None: value = value.replace(tzinfo=UTC) self.value = value self.locale = Locale.parse(locale) def __getitem__(self, name): char = name[0] num = len(name) if char == 'G': return self.format_era(char, num) elif char in ('y', 'Y', 'u'): return self.format_year(char, num) elif char in ('Q', 'q'): return self.format_quarter(char, num) elif char in ('M', 'L'): return self.format_month(char, num) elif char in ('w', 'W'): return self.format_week(char, num) elif char == 'd': return self.format(self.value.day, num) elif char == 'D': return self.format_day_of_year(num) elif char == 'F': return self.format_day_of_week_in_month() elif char in ('E', 'e', 'c'): return self.format_weekday(char, num) elif char in ('a', 'b', 'B'): return self.format_period(char, num) elif char == 'h': if self.value.hour % 12 == 0: return self.format(12, num) else: return self.format(self.value.hour % 12, num) elif char == 'H': return self.format(self.value.hour, num) elif char == 'K': return self.format(self.value.hour % 12, num) elif char == 'k': if self.value.hour == 0: return self.format(24, num) else: return self.format(self.value.hour, num) elif char == 'm': return self.format(self.value.minute, num) elif char == 's': return self.format(self.value.second, num) elif char == 'S': return self.format_frac_seconds(num) elif char == 'A': return self.format_milliseconds_in_day(num) elif char in ('z', 'Z', 'v', 'V', 'x', 'X', 'O'): return self.format_timezone(char, num) else: raise KeyError('Unsupported date/time field %r' % char) def extract(self, char): char = str(char)[0] if char == 'y': return self.value.year elif char == 'M': return self.value.month elif char == 'd': return self.value.day elif char == 'H': return self.value.hour elif char == 'h': return self.value.hour % 12 or 12 elif char == 'm': return self.value.minute elif char == 'a': return int(self.value.hour >= 12) # 0 for am, 1 for pm else: raise NotImplementedError("Not implemented: extracting %r from %r" % (char, self.value)) def format_era(self, char, num): width = {3: 'abbreviated', 4: 'wide', 5: 'narrow'}[max(3, num)] era = int(self.value.year >= 0) return get_era_names(width, self.locale)[era] def format_year(self, char, num): value = self.value.year if char.isupper(): week = self.get_week_number(self.get_day_of_year()) if week == 0: value -= 1 year = self.format(value, num) if num == 2: year = year[-2:] return year def format_quarter(self, char, num): quarter = (self.value.month - 1) // 3 + 1 if num <= 2: return '%0*d' % (num, quarter) width = {3: 'abbreviated', 4: 'wide', 5: 'narrow'}[num] context = {'Q': 'format', 'q': 'stand-alone'}[char] return get_quarter_names(width, context, self.locale)[quarter] def format_month(self, char, num): if num <= 2: return '%0*d' % (num, self.value.month) width = {3: 'abbreviated', 4: 'wide', 5: 'narrow'}[num] context = {'M': 'format', 'L': 'stand-alone'}[char] return get_month_names(width, context, self.locale)[self.value.month] def format_week(self, char, num): if char.islower(): # week of year day_of_year = self.get_day_of_year() week = self.get_week_number(day_of_year) if week == 0: date = self.value - timedelta(days=day_of_year) week = self.get_week_number(self.get_day_of_year(date), date.weekday()) return self.format(week, num) else: # week of month week = self.get_week_number(self.value.day) if week == 0: date = self.value - timedelta(days=self.value.day) week = self.get_week_number(date.day, date.weekday()) return '%d' % week def format_weekday(self, char='E', num=4): """ Return weekday from parsed datetime according to format pattern. >>> format = DateTimeFormat(date(2016, 2, 28), Locale.parse('en_US')) >>> format.format_weekday() u'Sunday' 'E': Day of week - Use one through three letters for the abbreviated day name, four for the full (wide) name, five for the narrow name, or six for the short name. >>> format.format_weekday('E',2) u'Sun' 'e': Local day of week. Same as E except adds a numeric value that will depend on the local starting day of the week, using one or two letters. For this example, Monday is the first day of the week. >>> format.format_weekday('e',2) '01' 'c': Stand-Alone local day of week - Use one letter for the local numeric value (same as 'e'), three for the abbreviated day name, four for the full (wide) name, five for the narrow name, or six for the short name. >>> format.format_weekday('c',1) '1' :param char: pattern format character ('e','E','c') :param num: count of format character """ if num < 3: if char.islower(): value = 7 - self.locale.first_week_day + self.value.weekday() return self.format(value % 7 + 1, num) num = 3 weekday = self.value.weekday() width = {3: 'abbreviated', 4: 'wide', 5: 'narrow', 6: 'short'}[num] if char == 'c': context = 'stand-alone' else: context = 'format' return get_day_names(width, context, self.locale)[weekday] def format_day_of_year(self, num): return self.format(self.get_day_of_year(), num) def format_day_of_week_in_month(self): return '%d' % ((self.value.day - 1) // 7 + 1) def format_period(self, char, num): """ Return period from parsed datetime according to format pattern. >>> format = DateTimeFormat(time(13, 42), 'fi_FI') >>> format.format_period('a', 1) u'ip.' >>> format.format_period('b', 1) u'iltap.' >>> format.format_period('b', 4) u'iltapäivä' >>> format.format_period('B', 4) u'iltapäivällä' >>> format.format_period('B', 5) u'ip.' >>> format = DateTimeFormat(datetime(2022, 4, 28, 6, 27), 'zh_Hant') >>> format.format_period('a', 1) u'上午' >>> format.format_period('b', 1) u'清晨' >>> format.format_period('B', 1) u'清晨' :param char: pattern format character ('a', 'b', 'B') :param num: count of format character """ widths = [{3: 'abbreviated', 4: 'wide', 5: 'narrow'}[max(3, num)], 'wide', 'narrow', 'abbreviated'] if char == 'a': period = 'pm' if self.value.hour >= 12 else 'am' context = 'format' else: period = get_period_id(self.value, locale=self.locale) context = 'format' if char == 'B' else 'stand-alone' for width in widths: period_names = get_period_names(context=context, width=width, locale=self.locale) if period in period_names: return period_names[period] raise ValueError('Could not format period %s in %s' % (period, self.locale)) def format_frac_seconds(self, num): """ Return fractional seconds. Rounds the time's microseconds to the precision given by the number \ of digits passed in. """ value = self.value.microsecond / 1000000 return self.format(round(value, num) * 10**num, num) def format_milliseconds_in_day(self, num): msecs = self.value.microsecond // 1000 + self.value.second * 1000 + \ self.value.minute * 60000 + self.value.hour * 3600000 return self.format(msecs, num) def format_timezone(self, char, num): width = {3: 'short', 4: 'long', 5: 'iso8601'}[max(3, num)] if char == 'z': return get_timezone_name(self.value, width, locale=self.locale) elif char == 'Z': if num == 5: return get_timezone_gmt(self.value, width, locale=self.locale, return_z=True) return get_timezone_gmt(self.value, width, locale=self.locale) elif char == 'O': if num == 4: return get_timezone_gmt(self.value, width, locale=self.locale) # TODO: To add support for O:1 elif char == 'v': return get_timezone_name(self.value.tzinfo, width, locale=self.locale) elif char == 'V': if num == 1: return get_timezone_name(self.value.tzinfo, width, uncommon=True, locale=self.locale) elif num == 2: return get_timezone_name(self.value.tzinfo, locale=self.locale, return_zone=True) elif num == 3: return get_timezone_location(self.value.tzinfo, locale=self.locale, return_city=True) return get_timezone_location(self.value.tzinfo, locale=self.locale) # Included additional elif condition to add support for 'Xx' in timezone format elif char == 'X': if num == 1: return get_timezone_gmt(self.value, width='iso8601_short', locale=self.locale, return_z=True) elif num in (2, 4): return get_timezone_gmt(self.value, width='short', locale=self.locale, return_z=True) elif num in (3, 5): return get_timezone_gmt(self.value, width='iso8601', locale=self.locale, return_z=True) elif char == 'x': if num == 1: return get_timezone_gmt(self.value, width='iso8601_short', locale=self.locale) elif num in (2, 4): return get_timezone_gmt(self.value, width='short', locale=self.locale) elif num in (3, 5): return get_timezone_gmt(self.value, width='iso8601', locale=self.locale) def format(self, value, length): return '%0*d' % (length, value) def get_day_of_year(self, date=None): if date is None: date = self.value return (date - date.replace(month=1, day=1)).days + 1 def get_week_number(self, day_of_period, day_of_week=None): """Return the number of the week of a day within a period. This may be the week number in a year or the week number in a month. Usually this will return a value equal to or greater than 1, but if the first week of the period is so short that it actually counts as the last week of the previous period, this function will return 0. >>> format = DateTimeFormat(date(2006, 1, 8), Locale.parse('de_DE')) >>> format.get_week_number(6) 1 >>> format = DateTimeFormat(date(2006, 1, 8), Locale.parse('en_US')) >>> format.get_week_number(6) 2 :param day_of_period: the number of the day in the period (usually either the day of month or the day of year) :param day_of_week: the week day; if ommitted, the week day of the current date is assumed """ if day_of_week is None: day_of_week = self.value.weekday() first_day = (day_of_week - self.locale.first_week_day - day_of_period + 1) % 7 if first_day < 0: first_day += 7 week_number = (day_of_period + first_day - 1) // 7 if 7 - first_day >= self.locale.min_week_days: week_number += 1 return week_number PATTERN_CHARS = { 'G': [1, 2, 3, 4, 5], # era 'y': None, 'Y': None, 'u': None, # year 'Q': [1, 2, 3, 4, 5], 'q': [1, 2, 3, 4, 5], # quarter 'M': [1, 2, 3, 4, 5], 'L': [1, 2, 3, 4, 5], # month 'w': [1, 2], 'W': [1], # week 'd': [1, 2], 'D': [1, 2, 3], 'F': [1], 'g': None, # day 'E': [1, 2, 3, 4, 5, 6], 'e': [1, 2, 3, 4, 5, 6], 'c': [1, 3, 4, 5, 6], # week day 'a': [1, 2, 3, 4, 5], 'b': [1, 2, 3, 4, 5], 'B': [1, 2, 3, 4, 5], # period 'h': [1, 2], 'H': [1, 2], 'K': [1, 2], 'k': [1, 2], # hour 'm': [1, 2], # minute 's': [1, 2], 'S': None, 'A': None, # second 'z': [1, 2, 3, 4], 'Z': [1, 2, 3, 4, 5], 'O': [1, 4], 'v': [1, 4], # zone 'V': [1, 2, 3, 4], 'x': [1, 2, 3, 4, 5], 'X': [1, 2, 3, 4, 5] # zone } #: The pattern characters declared in the Date Field Symbol Table #: (https://www.unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table) #: in order of decreasing magnitude. PATTERN_CHAR_ORDER = "GyYuUQqMLlwWdDFgEecabBChHKkjJmsSAzZOvVXx" _pattern_cache = {} def parse_pattern(pattern): """Parse date, time, and datetime format patterns. >>> parse_pattern("MMMMd").format u'%(MMMM)s%(d)s' >>> parse_pattern("MMM d, yyyy").format u'%(MMM)s %(d)s, %(yyyy)s' Pattern can contain literal strings in single quotes: >>> parse_pattern("H:mm' Uhr 'z").format u'%(H)s:%(mm)s Uhr %(z)s' An actual single quote can be used by using two adjacent single quote characters: >>> parse_pattern("hh' o''clock'").format u"%(hh)s o'clock" :param pattern: the formatting pattern to parse """ if type(pattern) is DateTimePattern: return pattern if pattern in _pattern_cache: return _pattern_cache[pattern] result = [] for tok_type, tok_value in tokenize_pattern(pattern): if tok_type == "chars": result.append(tok_value.replace('%', '%%')) elif tok_type == "field": fieldchar, fieldnum = tok_value limit = PATTERN_CHARS[fieldchar] if limit and fieldnum not in limit: raise ValueError('Invalid length for field: %r' % (fieldchar * fieldnum)) result.append('%%(%s)s' % (fieldchar * fieldnum)) else: raise NotImplementedError("Unknown token type: %s" % tok_type) _pattern_cache[pattern] = pat = DateTimePattern(pattern, u''.join(result)) return pat def tokenize_pattern(pattern): """ Tokenize date format patterns. Returns a list of (token_type, token_value) tuples. ``token_type`` may be either "chars" or "field". For "chars" tokens, the value is the literal value. For "field" tokens, the value is a tuple of (field character, repetition count). :param pattern: Pattern string :type pattern: str :rtype: list[tuple] """ result = [] quotebuf = None charbuf = [] fieldchar = [''] fieldnum = [0] def append_chars(): result.append(('chars', ''.join(charbuf).replace('\0', "'"))) del charbuf[:] def append_field(): result.append(('field', (fieldchar[0], fieldnum[0]))) fieldchar[0] = '' fieldnum[0] = 0 for idx, char in enumerate(pattern.replace("''", '\0')): if quotebuf is None: if char == "'": # quote started if fieldchar[0]: append_field() elif charbuf: append_chars() quotebuf = [] elif char in PATTERN_CHARS: if charbuf: append_chars() if char == fieldchar[0]: fieldnum[0] += 1 else: if fieldchar[0]: append_field() fieldchar[0] = char fieldnum[0] = 1 else: if fieldchar[0]: append_field() charbuf.append(char) elif quotebuf is not None: if char == "'": # end of quote charbuf.extend(quotebuf) quotebuf = None else: # inside quote quotebuf.append(char) if fieldchar[0]: append_field() elif charbuf: append_chars() return result def untokenize_pattern(tokens): """ Turn a date format pattern token stream back into a string. This is the reverse operation of ``tokenize_pattern``. :type tokens: Iterable[tuple] :rtype: str """ output = [] for tok_type, tok_value in tokens: if tok_type == "field": output.append(tok_value[0] * tok_value[1]) elif tok_type == "chars": if not any(ch in PATTERN_CHARS for ch in tok_value): # No need to quote output.append(tok_value) else: output.append("'%s'" % tok_value.replace("'", "''")) return "".join(output) def split_interval_pattern(pattern): """ Split an interval-describing datetime pattern into multiple pieces. > The pattern is then designed to be broken up into two pieces by determining the first repeating field. - https://www.unicode.org/reports/tr35/tr35-dates.html#intervalFormats >>> split_interval_pattern(u'E d.M. \u2013 E d.M.') [u'E d.M. \u2013 ', 'E d.M.'] >>> split_interval_pattern("Y 'text' Y 'more text'") ["Y 'text '", "Y 'more text'"] >>> split_interval_pattern(u"E, MMM d \u2013 E") [u'E, MMM d \u2013 ', u'E'] >>> split_interval_pattern("MMM d") ['MMM d'] >>> split_interval_pattern("y G") ['y G'] >>> split_interval_pattern(u"MMM d \u2013 d") [u'MMM d \u2013 ', u'd'] :param pattern: Interval pattern string :return: list of "subpatterns" """ seen_fields = set() parts = [[]] for tok_type, tok_value in tokenize_pattern(pattern): if tok_type == "field": if tok_value[0] in seen_fields: # Repeated field parts.append([]) seen_fields.clear() seen_fields.add(tok_value[0]) parts[-1].append((tok_type, tok_value)) return [untokenize_pattern(tokens) for tokens in parts] def match_skeleton(skeleton, options, allow_different_fields=False): """ Find the closest match for the given datetime skeleton among the options given. This uses the rules outlined in the TR35 document. >>> match_skeleton('yMMd', ('yMd', 'yMMMd')) 'yMd' >>> match_skeleton('yMMd', ('jyMMd',), allow_different_fields=True) 'jyMMd' >>> match_skeleton('yMMd', ('qyMMd',), allow_different_fields=False) >>> match_skeleton('hmz', ('hmv',)) 'hmv' :param skeleton: The skeleton to match :type skeleton: str :param options: An iterable of other skeletons to match against :type options: Iterable[str] :return: The closest skeleton match, or if no match was found, None. :rtype: str|None """ # TODO: maybe implement pattern expansion? # Based on the implementation in # http://source.icu-project.org/repos/icu/icu4j/trunk/main/classes/core/src/com/ibm/icu/text/DateIntervalInfo.java # Filter out falsy values and sort for stability; when `interval_formats` is passed in, there may be a None key. options = sorted(option for option in options if option) if 'z' in skeleton and not any('z' in option for option in options): skeleton = skeleton.replace('z', 'v') get_input_field_width = dict(t[1] for t in tokenize_pattern(skeleton) if t[0] == "field").get best_skeleton = None best_distance = None for option in options: get_opt_field_width = dict(t[1] for t in tokenize_pattern(option) if t[0] == "field").get distance = 0 for field in PATTERN_CHARS: input_width = get_input_field_width(field, 0) opt_width = get_opt_field_width(field, 0) if input_width == opt_width: continue if opt_width == 0 or input_width == 0: if not allow_different_fields: # This one is not okay option = None break distance += 0x1000 # Magic weight constant for "entirely different fields" elif field == 'M' and ((input_width > 2 and opt_width <= 2) or (input_width <= 2 and opt_width > 2)): distance += 0x100 # Magic weight for "text turns into a number" else: distance += abs(input_width - opt_width) if not option: # We lost the option along the way (probably due to "allow_different_fields") continue if not best_skeleton or distance < best_distance: best_skeleton = option best_distance = distance if distance == 0: # Found a perfect match! break return best_skeleton