Source code for logilab.common.date

# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of logilab-common.
#
# logilab-common is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option) any
# later version.
#
# logilab-common is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with logilab-common.  If not, see <http://www.gnu.org/licenses/>.
"""Date manipulation helper functions."""

__docformat__ = "restructuredtext en"

import math
import re
import sys
from locale import getlocale, LC_TIME
from datetime import date, time, datetime, timedelta
from time import strptime as time_strptime
from calendar import monthrange, timegm
from typing import Union, List, Any, Optional, Generator

try:
    from mx.DateTime import RelativeDateTime, Date, DateTimeType
except ImportError:
    endOfMonth = None
    DateTimeType = datetime
else:
    endOfMonth = RelativeDateTime(months=1, day=-1)

# NOTE: should we implement a compatibility layer between date representations
#       as we have in lgc.db ?

FRENCH_FIXED_HOLIDAYS = {
    "jour_an": "%s-01-01",
    "fete_travail": "%s-05-01",
    "armistice1945": "%s-05-08",
    "fete_nat": "%s-07-14",
    "assomption": "%s-08-15",
    "toussaint": "%s-11-01",
    "armistice1918": "%s-11-11",
    "noel": "%s-12-25",
}

FRENCH_MOBILE_HOLIDAYS = {
    "paques2004": "2004-04-12",
    "ascension2004": "2004-05-20",
    "pentecote2004": "2004-05-31",
    "paques2005": "2005-03-28",
    "ascension2005": "2005-05-05",
    "pentecote2005": "2005-05-16",
    "paques2006": "2006-04-17",
    "ascension2006": "2006-05-25",
    "pentecote2006": "2006-06-05",
    "paques2007": "2007-04-09",
    "ascension2007": "2007-05-17",
    "pentecote2007": "2007-05-28",
    "paques2008": "2008-03-24",
    "ascension2008": "2008-05-01",
    "pentecote2008": "2008-05-12",
    "paques2009": "2009-04-13",
    "ascension2009": "2009-05-21",
    "pentecote2009": "2009-06-01",
    "paques2010": "2010-04-05",
    "ascension2010": "2010-05-13",
    "pentecote2010": "2010-05-24",
    "paques2011": "2011-04-25",
    "ascension2011": "2011-06-02",
    "pentecote2011": "2011-06-13",
    "paques2012": "2012-04-09",
    "ascension2012": "2012-05-17",
    "pentecote2012": "2012-05-28",
}

# XXX this implementation cries for multimethod dispatching


[docs]def get_step(dateobj: Union[date, datetime], nbdays: int = 1) -> timedelta: # assume date is either a python datetime or a mx.DateTime object if isinstance(dateobj, date): return ONEDAY * nbdays return nbdays # mx.DateTime is ok with integers
[docs]def datefactory( year: int, month: int, day: int, sampledate: Union[date, datetime] ) -> Union[date, datetime]: # assume date is either a python datetime or a mx.DateTime object if isinstance(sampledate, datetime): return datetime(year, month, day) if isinstance(sampledate, date): return date(year, month, day) return Date(year, month, day)
[docs]def weekday(dateobj: Union[date, datetime]) -> int: # assume date is either a python datetime or a mx.DateTime object if isinstance(dateobj, date): return dateobj.weekday() return dateobj.day_of_week
[docs]def str2date(datestr: str, sampledate: Union[date, datetime]) -> Union[date, datetime]: # NOTE: datetime.strptime is not an option until we drop py2.4 compat year, month, day = [int(chunk) for chunk in datestr.split("-")] return datefactory(year, month, day, sampledate)
[docs]def days_between(start: Union[date, datetime], end: Union[date, datetime]) -> int: if isinstance(start, date): # mypy: No overload variant of "__sub__" of "datetime" matches argument type "date" # we ensure that end is a date assert isinstance(end, date) delta = end - start # type: ignore # datetime.timedelta.days is always an integer (floored) if delta.seconds: return delta.days + 1 return delta.days else: return int(math.ceil((end - start).days))
[docs]def get_national_holidays( begin: Union[date, datetime], end: Union[date, datetime] ) -> Union[List[date], List[datetime]]: """return french national days off between begin and end""" begin = datefactory(begin.year, begin.month, begin.day, begin) end = datefactory(end.year, end.month, end.day, end) holidays = [str2date(datestr, begin) for datestr in FRENCH_MOBILE_HOLIDAYS.values()] for year in range(begin.year, end.year + 1): for datestr in FRENCH_FIXED_HOLIDAYS.values(): date = str2date(datestr % year, begin) if date not in holidays: holidays.append(date) return [day for day in holidays if begin <= day < end]
[docs]def add_days_worked(start: date, days: int) -> date: """adds date but try to only take days worked into account""" step = get_step(start) weeks, plus = divmod(days, 5) end = start + ((weeks * 7) + plus) * step if weekday(end) >= 5: # saturday or sunday end += 2 * step end += len([x for x in get_national_holidays(start, end + step) if weekday(x) < 5]) * step if weekday(end) >= 5: # saturday or sunday end += 2 * step return end
[docs]def nb_open_days(start: Union[date, datetime], end: Union[date, datetime]) -> int: assert start <= end step = get_step(start) days = days_between(start, end) weeks, plus = divmod(days, 7) if weekday(start) > weekday(end): plus -= 2 elif weekday(end) == 6: plus -= 1 open_days = weeks * 5 + plus nb_week_holidays = len( [x for x in get_national_holidays(start, end + step) if weekday(x) < 5 and x < end] ) open_days -= nb_week_holidays if open_days < 0: return 0 return open_days
[docs]def date_range( begin: date, end: date, incday: Optional[Any] = None, incmonth: Optional[bool] = None ) -> Generator[date, Any, None]: """yields each date between begin and end :param begin: the start date :param end: the end date :param incr: the step to use to iterate over dates. Default is one day. :param include: None (means no exclusion) or a function taking a date as parameter, and returning True if the date should be included. When using mx datetime, you should *NOT* use incmonth argument, use instead oneDay, oneHour, oneMinute, oneSecond, oneWeek or endOfMonth (to enumerate months) as `incday` argument """ assert not (incday and incmonth) begin = todate(begin) end = todate(end) if incmonth: while begin < end: yield begin begin = next_month(begin, incmonth) else: incr = get_step(begin, incday or 1) while begin < end: yield begin begin += incr
# makes py datetime usable ##################################################### ONEDAY: timedelta = timedelta(days=1) ONEWEEK: timedelta = timedelta(days=7)
[docs]def strptime_time(value, format="%H:%M"): return time(*time_strptime(value, format)[3:6])
[docs]def todate(somedate: date) -> date: """return a date from a date (leaving unchanged) or a datetime""" if isinstance(somedate, datetime): return date(somedate.year, somedate.month, somedate.day) assert isinstance(somedate, (date, DateTimeType)), repr(somedate) return somedate
[docs]def totime(somedate): """return a time from a time (leaving unchanged), date or datetime""" # XXX mx compat if not isinstance(somedate, time): return time(somedate.hour, somedate.minute, somedate.second) assert isinstance(somedate, (time)), repr(somedate) return somedate
[docs]def todatetime(somedate): """return a date from a date (leaving unchanged) or a datetime""" # take care, datetime is a subclass of date if isinstance(somedate, datetime): return somedate assert isinstance(somedate, (date, DateTimeType)), repr(somedate) return datetime(somedate.year, somedate.month, somedate.day)
[docs]def datetime2ticks(somedate: Union[date, datetime]) -> int: return timegm(somedate.timetuple()) * 1000 + int(getattr(somedate, "microsecond", 0) / 1000)
[docs]def ticks2datetime(ticks: int) -> datetime: miliseconds, microseconds = divmod(ticks, 1000) try: return datetime.fromtimestamp(miliseconds) except (ValueError, OverflowError): epoch = datetime.fromtimestamp(0) nb_days, seconds = divmod(int(miliseconds), 86400) delta = timedelta(nb_days, seconds=seconds, microseconds=microseconds) try: return epoch + delta except (ValueError, OverflowError): raise
[docs]def days_in_month(somedate: date) -> int: return monthrange(somedate.year, somedate.month)[1]
[docs]def days_in_year(somedate): feb = date(somedate.year, 2, 1) if days_in_month(feb) == 29: return 366 else: return 365
[docs]def previous_month(somedate, nbmonth=1): while nbmonth: somedate = first_day(somedate) - ONEDAY nbmonth -= 1 return somedate
[docs]def next_month(somedate: date, nbmonth: int = 1) -> date: while nbmonth: somedate = last_day(somedate) + ONEDAY nbmonth -= 1 return somedate
[docs]def first_day(somedate): return date(somedate.year, somedate.month, 1)
[docs]def last_day(somedate: date) -> date: return date(somedate.year, somedate.month, days_in_month(somedate))
[docs]def ustrftime(somedate: datetime, fmt: str = "%Y-%m-%d") -> str: """like strftime, but returns a unicode string instead of an encoded string which may be problematic with localized date. """ if sys.version_info >= (3, 3): # datetime.date.strftime() supports dates since year 1 in Python >=3.3. return somedate.strftime(fmt) else: try: if sys.version_info < (3, 0): encoding = getlocale(LC_TIME)[1] or "ascii" return str(somedate.strftime(str(fmt)), encoding) else: return somedate.strftime(fmt) except ValueError: if somedate.year >= 1900: raise # datetime is not happy with dates before 1900 # we try to work around this, assuming a simple # format string fields = { "Y": somedate.year, "m": somedate.month, "d": somedate.day, } if isinstance(somedate, datetime): fields.update({"H": somedate.hour, "M": somedate.minute, "S": somedate.second}) fmt = re.sub("%([YmdHMS])", r"%(\1)02d", fmt) return str(fmt) % fields
[docs]def utcdatetime(dt: datetime) -> datetime: if dt.tzinfo is None: return dt # mypy: No overload variant of "__sub__" of "datetime" matches argument type "None" return dt.replace(tzinfo=None) - dt.utcoffset() # type: ignore
[docs]def utctime(dt): if dt.tzinfo is None: return dt return (dt + dt.utcoffset() + dt.dst()).replace(tzinfo=None)
[docs]def datetime_to_seconds(date): """return the number of seconds since the begining of the day for that date""" return date.second + 60 * date.minute + 3600 * date.hour
[docs]def timedelta_to_days(delta): """return the time delta as a number of seconds""" return delta.days + delta.seconds / (3600 * 24)
[docs]def timedelta_to_seconds(delta): """return the time delta as a fraction of days""" return delta.days * (3600 * 24) + delta.seconds