# This software is open source software available under the BSD-3 license.
#
# Copyright (c) 2019 Triad National Security, LLC. All rights reserved.
# Copyright (c) 2019 Lawrence Livermore National Security, LLC. All rights
# reserved.
# Copyright (c) 2019 UT-Battelle, LLC. All rights reserved.
#
# Additional copyright and license information can be found in the LICENSE file
# distributed with this code, or at
# https://raw.githubusercontent.com/MPAS-Dev/MPAS-Analysis/master/LICENSE
from __future__ import absolute_import, division, print_function, \
unicode_literals
import datetime
from dateutil.relativedelta import relativedelta
from calendar import monthrange, isleap
[docs]class MpasRelativeDelta(relativedelta):
"""
``MpasRelativeDelta`` is a subclass of ``dateutil.relativedelta`` for
relative time intervals with different MPAS calendars.
Only relative intervals (years, months, etc.) are supported and not the
absolute date specifications (year, month, etc.). Addition/subtraction
of ``datetime.datetime`` objects or other ``MpasRelativeDelta`` (but
currently not ``datetime.date``, ``datetime.timedelta`` or other related
objects) is supported.
"""
# Authors
# -------
# Xylar Asay-Davis
[docs] def __init__(self, dt1=None, dt2=None, years=0, months=0, days=0,
hours=0, minutes=0, seconds=0, calendar='gregorian'):
if calendar not in ['gregorian', 'gregorian_noleap']:
raise ValueError('Unsupported MPAs calendar {}'.format(calendar))
self.calendar = calendar
super(MpasRelativeDelta, self).__init__(dt1=dt1, dt2=dt2, years=years,
months=months, days=days,
hours=hours, minutes=minutes,
seconds=seconds)
def __add__(self, other):
if not isinstance(other, (datetime.datetime, MpasRelativeDelta)):
return NotImplemented
if isinstance(other, MpasRelativeDelta):
if self.calendar != other.calendar:
raise ValueError('MpasRelativeDelta objects can only be added '
'if their calendars match.')
years = self.years + other.years
months = self.months + other.months
if months > 12:
years += 1
months -= 12
elif months < 1:
years -= 1
months += 12
return self.__class__(years=years,
months=months,
days=self.days + other.days,
hours=self.hours + other.hours,
minutes=self.minutes + other.minutes,
seconds=self.seconds + other.seconds,
calendar=self.calendar)
year = other.year + self.years
month = other.month
if self.months != 0:
assert 1 <= abs(self.months) <= 12
month += self.months
if month > 12:
year += 1
month -= 12
elif month < 1:
year -= 1
month += 12
if self.calendar == 'gregorian':
daysInMonth = monthrange(year, month)[1]
elif self.calendar == 'gregorian_noleap':
# use year 0001, which is not a leapyear
daysInMonth = monthrange(1, month)[1]
day = min(daysInMonth, other.day)
repl = {"year": year, "month": month, "day": day}
days = self.days
if self.calendar == 'gregorian_noleap' and isleap(year):
if month == 2 and day + days >= 29:
# skip forward over the leap day
days += 1
elif month == 3 and day + days <= 0:
# skip backward over the leap day
days -= 1
return (other.replace(**repl) +
datetime.timedelta(days=days,
hours=self.hours,
minutes=self.minutes,
seconds=self.seconds))
def __radd__(self, other):
return self.__add__(other)
def __rsub__(self, other):
return self.__neg__().__add__(other)
def __sub__(self, other):
if not isinstance(other, MpasRelativeDelta):
return NotImplemented
return self.__add__(other.__neg__())
def __neg__(self):
return self.__class__(years=-self.years,
months=-self.months,
days=-self.days,
hours=-self.hours,
minutes=-self.minutes,
seconds=-self.seconds,
calendar=self.calendar)
def __mul__(self, other):
try:
f = float(other)
except TypeError:
return NotImplemented
return self.__class__(years=int(self.years * f),
months=int(self.months * f),
days=int(self.days * f),
hours=int(self.hours * f),
minutes=int(self.minutes * f),
seconds=int(self.seconds * f),
calendar=self.calendar)
__rmul__ = __mul__
def __div__(self, other):
try:
reciprocal = 1 / float(other)
except TypeError:
return NotImplemented
return self.__mul__(reciprocal)
__truediv__ = __div__
def __repr__(self):
outList = []
for attr in ["years", "months", "days", "leapdays",
"hours", "minutes", "seconds", "microseconds"]:
value = getattr(self, attr)
if value:
outList.append("{attr}={value:+g}".format(attr=attr,
value=value))
outList.append("calendar='{}'".format(self.calendar))
return "{classname}({attrs})".format(classname=self.__class__.__name__,
attrs=", ".join(outList))
# vim: foldmethod=marker ai ts=4 sts=4 et sw=4 ft=python