+
−""" This module provides a set of constructors and routines to convert
+
−    between DateTime[Delta] instances and ISO representations of date
+
−    and time.
+
−
+
−    Note: Timezones are only interpreted by ParseDateTimeGMT(). All
+
−    other constructors silently ignore the time zone information.
+
−
+
−    Copyright (c) 1998-2000, Marc-Andre Lemburg; mailto:mal@lemburg.com
+
−    Copyright (c) 2000-2007, eGenix.com Software GmbH; mailto:info@egenix.com
+
−    See the documentation for further information on copyrights,
+
−    or contact the author.
+
−
+
−"""
+
−import DateTime,Timezone
+
−import re,string
+
−
+
−# Grammar: ISO 8601 (not all, but what we need from it)
+
−_year = '(?P<year>\d?\d\d\d)'
+
−_month = '(?P<month>\d?\d)'
+
−_day = '(?P<day>\d?\d)'
+
−_hour = '(?P<hour>\d?\d)'
+
−_minute = '(?P<minute>\d?\d)'
+
−_second = '(?P<second>\d?\d(?:\.\d+)?)'
+
−_sign = '(?P<sign>[-+])'
+
−_week = 'W(?P<week>\d?\d)'
+
−_zone = Timezone.isozone
+
−
+
−_weekdate = _year + '-?(?:' + _week + '-?' + _day + '?)?'
+
−_date = _year + '-?' + '(?:' + _month + '-?' + _day + '?)?'
+
−_time = _hour + ':?' + _minute + ':?' + _second + '?(?:' + _zone + ')?'
+
−
+
−isodatetimeRE = re.compile(_date + '(?:[ T]' + _time + ')?$')
+
−isodateRE = re.compile(_date + '$')
+
−isotimeRE = re.compile(_time + '$')
+
−isodeltaRE = re.compile(_sign + '?' + _time + '$')
+
−isoweekRE = re.compile(_weekdate + '$')
+
−isoweektimeRE = re.compile(_weekdate + '(?:[ T]' + _time + ')?$')
+
−
+
−def WeekTime(year,isoweek=1,isoday=1,hour=0,minute=0,second=0.0):
+
−
+
−    """Week(year,isoweek=1,isoday=1,hour=0,minute=0,second=0.0)
+
−
+
−       Returns a DateTime instance pointing to the given ISO week and
+
−       day.  isoday defaults to 1, which corresponds to Monday in the
+
−       ISO numbering. The time part is set as given.
+
−
+
−    """
+
−    d = DateTime.DateTime(year,1,1,hour,minute,second)
+
−    if d.iso_week[0] == year:
+
−        # 1.1. belongs to year (backup to Monday)
+
−        return d + (-d.day_of_week + 7 * (isoweek-1) + isoday-1)
+
−    else:
+
−        # 1.1. belongs to year-1 (advance to next Monday)
+
−        return d + (7-d.day_of_week + 7 * (isoweek-1) + isoday-1)
+
−
+
−# Alias
+
−Week = WeekTime
+
−
+
−# Aliases for the other constructors (they all happen to already use
+
−# ISO format)
+
−Date = DateTime.Date
+
−Time = DateTime.Time
+
−TimeDelta = DateTime.TimeDelta
+
−
+
−def ParseDateTime(isostring,parse_isodatetime=isodatetimeRE.match,
+
−
+
−                  strip=string.strip,atoi=string.atoi,atof=string.atof):
+
−
+
−    """ParseDateTime(isostring)
+
−
+
−       Returns a DateTime instance reflecting the given ISO date. A
+
−       time part is optional and must be delimited from the date by a
+
−       space or 'T'.
+
−
+
−       Time zone information is parsed, but not evaluated.
+
−
+
−    """
+
−    s = strip(isostring)
+
−    date = parse_isodatetime(s)
+
−    if not date:
+
−        raise ValueError,'wrong format, use YYYY-MM-DD HH:MM:SS'
+
−    year,month,day,hour,minute,second,zone = date.groups()
+
−    year = atoi(year)
+
−    if month is None:
+
−        month = 1
+
−    else:
+
−        month = atoi(month)
+
−    if day is None:
+
−        day = 1
+
−    else:
+
−        day = atoi(day)
+
−    if hour is None:
+
−        hour = 0
+
−    else:
+
−        hour = atoi(hour)
+
−    if minute is None:
+
−        minute = 0
+
−    else:
+
−        minute = atoi(minute)
+
−    if second is None:
+
−        second = 0.0
+
−    else:
+
−        second = atof(second)
+
−    return DateTime.DateTime(year,month,day,hour,minute,second)
+
−
+
−def ParseDateTimeGMT(isostring,parse_isodatetime=isodatetimeRE.match,
+
−
+
−                     strip=string.strip,atoi=string.atoi,atof=string.atof):
+
−
+
−    """ParseDateTimeGMT(isostring)
+
−
+
−       Returns a DateTime instance in UTC reflecting the given ISO
+
−       date. A time part is optional and must be delimited from the
+
−       date by a space or 'T'. Timezones are honored.
+
−
+
−    """
+
−    s = strip(isostring)
+
−    date = parse_isodatetime(s)
+
−    if not date:
+
−        raise ValueError,'wrong format, use YYYY-MM-DD HH:MM:SS'
+
−    year,month,day,hour,minute,second,zone = date.groups()
+
−    year = atoi(year)
+
−    if month is None:
+
−        month = 1
+
−    else:
+
−        month = atoi(month)
+
−    if day is None:
+
−        day = 1
+
−    else:
+
−        day = atoi(day)
+
−    if hour is None:
+
−        hour = 0
+
−    else:
+
−        hour = atoi(hour)
+
−    if minute is None:
+
−        minute = 0
+
−    else:
+
−        minute = atoi(minute)
+
−    if second is None:
+
−        second = 0.0
+
−    else:
+
−        second = atof(second)
+
−    offset = Timezone.utc_offset(zone)
+
−    return DateTime.DateTime(year,month,day,hour,minute,second) - offset
+
−
+
−# Alias
+
−ParseDateTimeUTC = ParseDateTimeGMT
+
−
+
−def ParseDate(isostring,parse_isodate=isodateRE.match,
+
−
+
−              strip=string.strip,atoi=string.atoi,atof=string.atof):
+
−
+
−    """ParseDate(isostring)
+
−
+
−       Returns a DateTime instance reflecting the given ISO date. A
+
−       time part may not be included.
+
−
+
−    """
+
−    s = strip(isostring)
+
−    date = parse_isodate(s)
+
−    if not date:
+
−        raise ValueError,'wrong format, use YYYY-MM-DD'
+
−    year,month,day = date.groups()
+
−    year = atoi(year)
+
−    if month is None:
+
−        month = 1
+
−    else:
+
−        month = atoi(month)
+
−    if day is None:
+
−        day = 1
+
−    else:
+
−        day = atoi(day)
+
−    return DateTime.DateTime(year,month,day)
+
−
+
−def ParseWeek(isostring,parse_isoweek=isoweekRE.match,
+
−
+
−              strip=string.strip,atoi=string.atoi,atof=string.atof):
+
−
+
−    """ParseWeek(isostring)
+
−
+
−       Returns a DateTime instance reflecting the given ISO date. A
+
−       time part may not be included.
+
−
+
−    """
+
−    s = strip(isostring)
+
−    date = parse_isoweek(s)
+
−    if not date:
+
−        raise ValueError,'wrong format, use yyyy-Www-d, e.g. 1998-W01-1'
+
−    year,week,day = date.groups()
+
−    year = atoi(year)
+
−    if week is None:
+
−        week = 1
+
−    else:
+
−        week = atoi(week)
+
−    if day is None:
+
−        day = 1
+
−    else:
+
−        day = atoi(day)
+
−    return Week(year,week,day)
+
−
+
−def ParseWeekTime(isostring,parse_isoweektime=isoweektimeRE.match,
+
−
+
−                  strip=string.strip,atoi=string.atoi,atof=string.atof):
+
−
+
−    """ParseWeekTime(isostring)
+
−
+
−       Returns a DateTime instance reflecting the given ISO date. A
+
−       time part is optional and must be delimited from the date by a
+
−       space or 'T'.
+
−
+
−    """
+
−    s = strip(isostring)
+
−    date = parse_isoweektime(s)
+
−    if not date:
+
−        raise ValueError,'wrong format, use e.g. "1998-W01-1 12:00:30"'
+
−    year,week,day,hour,minute,second,zone = date.groups()
+
−    year = atoi(year)
+
−    if week is None:
+
−        week = 1
+
−    else:
+
−        week = atoi(week)
+
−    if day is None:
+
−        day = 1
+
−    else:
+
−        day = atoi(day)
+
−    if hour is None:
+
−        hour = 0
+
−    else:
+
−        hour = atoi(hour)
+
−    if minute is None:
+
−        minute = 0
+
−    else:
+
−        minute = atoi(minute)
+
−    if second is None:
+
−        second = 0.0
+
−    else:
+
−        second = atof(second)
+
−    return WeekTime(year,week,day,hour,minute,second)
+
−
+
−def ParseTime(isostring,parse_isotime=isotimeRE.match,
+
−
+
−              strip=string.strip,atoi=string.atoi,atof=string.atof):
+
−
+
−    """ParseTime(isostring)
+
−
+
−       Returns a DateTimeDelta instance reflecting the given ISO time.
+
−       Hours and minutes must be given, seconds are
+
−       optional. Fractions of a second may also be used,
+
−       e.g. 12:23:12.34.
+
−
+
−    """
+
−    s = strip(isostring)
+
−    time = parse_isotime(s)
+
−    if not time:
+
−        raise ValueError,'wrong format, use HH:MM:SS'
+
−    hour,minute,second,zone = time.groups()
+
−    hour = atoi(hour)
+
−    minute = atoi(minute)
+
−    if second is not None:
+
−        second = atof(second)
+
−    else:
+
−        second = 0.0
+
−    return DateTime.TimeDelta(hour,minute,second)
+
−
+
−def ParseTimeDelta(isostring,parse_isodelta=isodeltaRE.match,
+
−
+
−                   strip=string.strip,atoi=string.atoi,atof=string.atof):
+
−
+
−    """ParseTimeDelta(isostring)
+
−
+
−       Returns a DateTimeDelta instance reflecting the given ISO time
+
−       as delta. Hours and minutes must be given, seconds are
+
−       optional. Fractions of a second may also be used,
+
−       e.g. 12:23:12.34. In addition to the ISO standard a sign may be
+
−       prepended to the time, e.g. -12:34.
+
−
+
−    """
+
−    s = strip(isostring)
+
−    time = parse_isodelta(s)
+
−    if not time:
+
−        raise ValueError,'wrong format, use [-]HH:MM:SS'
+
−    sign,hour,minute,second,zone = time.groups()
+
−    hour = atoi(hour)
+
−    minute = atoi(minute)
+
−    if second is not None:
+
−        second = atof(second)
+
−    else:
+
−        second = 0.0
+
−    if sign and sign == '-':
+
−        return -DateTime.TimeDelta(hour,minute,second)
+
−    else:
+
−        return DateTime.TimeDelta(hour,minute,second)
+
−
+
−def ParseAny(isostring):
+
−
+
−    """ParseAny(isostring)
+
−
+
−       Parses the given string and tries to convert it to a
+
−       DateTime[Delta] instance.
+
−
+
−    """
+
−    try:
+
−        return ParseDateTime(isostring)
+
−    except ValueError:
+
−        pass
+
−    try:
+
−        return ParseWeekTime(isostring)
+
−    except ValueError:
+
−        pass
+
−    try:
+
−        return ParseTimeDelta(isostring)
+
−    except ValueError:
+
−        raise ValueError,'unsupported format: "%s"' % isostring
+
−
+
−def str(datetime,tz=None):
+
−
+
−    """str(datetime,tz=DateTime.tz_offset(datetime))
+
−
+
−       Returns the datetime instance as ISO date string. tz can be
+
−       given as DateTimeDelta instance providing the time zone
+
−       difference from datetime's zone to UTC. It defaults to
+
−       DateTime.tz_offset(datetime) which assumes local time.
+
−
+
−    """
+
−    if tz is None:
+
−        tz = datetime.gmtoffset()
+
−    return '%04i-%02i-%02i %02i:%02i:%02i%+03i%02i' % (
+
−        datetime.year, datetime.month, datetime.day, 
+
−        datetime.hour, datetime.minute, datetime.second,
+
−        tz.hour,tz.minute)
+
−
+
−def strGMT(datetime):
+
−
+
−    """strGMT(datetime)
+
−
+
−       Returns the datetime instance as ISO date string assuming it is
+
−       given in GMT.
+
−
+
−    """
+
−    return '%04i-%02i-%02i %02i:%02i:%02i+0000' % (
+
−        datetime.year, datetime.month, datetime.day, 
+
−        datetime.hour, datetime.minute, datetime.second)
+
−
+
−def strUTC(datetime):
+
−
+
−    """strUTC(datetime)
+
−
+
−       Returns the datetime instance as ISO date string assuming it is
+
−       given in UTC.
+
−
+
−    """
+
−    return '%04i-%02i-%02i %02i:%02i:%02i+0000' % (
+
−        datetime.year, datetime.month, datetime.day, 
+
−        datetime.hour, datetime.minute, datetime.second)
+
−
+
−# Testing
+
−if __name__ == '__main__':
+
−    e = DateTime.Date(1900,1,1)
+
−    for i in range(100000):
+
−        d = e + i
+
−        year,week,day = d.iso_week
+
−        c = WeekTime(year,week,day)
+
−        if d != c:
+
−            print ' Check %s (given; %i) != %s (parsed)' % (d,d.day_of_week,c)
+
−        elif i % 1000 == 0:
+
−            print d,'ok'