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Diffstat (limited to 'src/dateutil/relativedelta.py')
| -rw-r--r-- | src/dateutil/relativedelta.py | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/src/dateutil/relativedelta.py b/src/dateutil/relativedelta.py new file mode 100644 index 0000000..a9e85f7 --- /dev/null +++ b/src/dateutil/relativedelta.py @@ -0,0 +1,599 @@ +# -*- coding: utf-8 -*- +import datetime +import calendar + +import operator +from math import copysign + +from six import integer_types +from warnings import warn + +from ._common import weekday + +MO, TU, WE, TH, FR, SA, SU = weekdays = tuple(weekday(x) for x in range(7)) + +__all__ = ["relativedelta", "MO", "TU", "WE", "TH", "FR", "SA", "SU"] + + +class relativedelta(object): + """ + The relativedelta type is designed to be applied to an existing datetime and + can replace specific components of that datetime, or represents an interval + of time. + + It is based on the specification of the excellent work done by M.-A. Lemburg + in his + `mx.DateTime <https://www.egenix.com/products/python/mxBase/mxDateTime/>`_ extension. + However, notice that this type does *NOT* implement the same algorithm as + his work. Do *NOT* expect it to behave like mx.DateTime's counterpart. + + There are two different ways to build a relativedelta instance. The + first one is passing it two date/datetime classes:: + + relativedelta(datetime1, datetime2) + + The second one is passing it any number of the following keyword arguments:: + + relativedelta(arg1=x,arg2=y,arg3=z...) + + year, month, day, hour, minute, second, microsecond: + Absolute information (argument is singular); adding or subtracting a + relativedelta with absolute information does not perform an arithmetic + operation, but rather REPLACES the corresponding value in the + original datetime with the value(s) in relativedelta. + + years, months, weeks, days, hours, minutes, seconds, microseconds: + Relative information, may be negative (argument is plural); adding + or subtracting a relativedelta with relative information performs + the corresponding arithmetic operation on the original datetime value + with the information in the relativedelta. + + weekday: + One of the weekday instances (MO, TU, etc) available in the + relativedelta module. These instances may receive a parameter N, + specifying the Nth weekday, which could be positive or negative + (like MO(+1) or MO(-2)). Not specifying it is the same as specifying + +1. You can also use an integer, where 0=MO. This argument is always + relative e.g. if the calculated date is already Monday, using MO(1) + or MO(-1) won't change the day. To effectively make it absolute, use + it in combination with the day argument (e.g. day=1, MO(1) for first + Monday of the month). + + leapdays: + Will add given days to the date found, if year is a leap + year, and the date found is post 28 of february. + + yearday, nlyearday: + Set the yearday or the non-leap year day (jump leap days). + These are converted to day/month/leapdays information. + + There are relative and absolute forms of the keyword + arguments. The plural is relative, and the singular is + absolute. For each argument in the order below, the absolute form + is applied first (by setting each attribute to that value) and + then the relative form (by adding the value to the attribute). + + The order of attributes considered when this relativedelta is + added to a datetime is: + + 1. Year + 2. Month + 3. Day + 4. Hours + 5. Minutes + 6. Seconds + 7. Microseconds + + Finally, weekday is applied, using the rule described above. + + For example + + >>> from datetime import datetime + >>> from dateutil.relativedelta import relativedelta, MO + >>> dt = datetime(2018, 4, 9, 13, 37, 0) + >>> delta = relativedelta(hours=25, day=1, weekday=MO(1)) + >>> dt + delta + datetime.datetime(2018, 4, 2, 14, 37) + + First, the day is set to 1 (the first of the month), then 25 hours + are added, to get to the 2nd day and 14th hour, finally the + weekday is applied, but since the 2nd is already a Monday there is + no effect. + + """ + + def __init__(self, dt1=None, dt2=None, + years=0, months=0, days=0, leapdays=0, weeks=0, + hours=0, minutes=0, seconds=0, microseconds=0, + year=None, month=None, day=None, weekday=None, + yearday=None, nlyearday=None, + hour=None, minute=None, second=None, microsecond=None): + + if dt1 and dt2: + # datetime is a subclass of date. So both must be date + if not (isinstance(dt1, datetime.date) and + isinstance(dt2, datetime.date)): + raise TypeError("relativedelta only diffs datetime/date") + + # We allow two dates, or two datetimes, so we coerce them to be + # of the same type + if (isinstance(dt1, datetime.datetime) != + isinstance(dt2, datetime.datetime)): + if not isinstance(dt1, datetime.datetime): + dt1 = datetime.datetime.fromordinal(dt1.toordinal()) + elif not isinstance(dt2, datetime.datetime): + dt2 = datetime.datetime.fromordinal(dt2.toordinal()) + + self.years = 0 + self.months = 0 + self.days = 0 + self.leapdays = 0 + self.hours = 0 + self.minutes = 0 + self.seconds = 0 + self.microseconds = 0 + self.year = None + self.month = None + self.day = None + self.weekday = None + self.hour = None + self.minute = None + self.second = None + self.microsecond = None + self._has_time = 0 + + # Get year / month delta between the two + months = (dt1.year - dt2.year) * 12 + (dt1.month - dt2.month) + self._set_months(months) + + # Remove the year/month delta so the timedelta is just well-defined + # time units (seconds, days and microseconds) + dtm = self.__radd__(dt2) + + # If we've overshot our target, make an adjustment + if dt1 < dt2: + compare = operator.gt + increment = 1 + else: + compare = operator.lt + increment = -1 + + while compare(dt1, dtm): + months += increment + self._set_months(months) + dtm = self.__radd__(dt2) + + # Get the timedelta between the "months-adjusted" date and dt1 + delta = dt1 - dtm + self.seconds = delta.seconds + delta.days * 86400 + self.microseconds = delta.microseconds + else: + # Check for non-integer values in integer-only quantities + if any(x is not None and x != int(x) for x in (years, months)): + raise ValueError("Non-integer years and months are " + "ambiguous and not currently supported.") + + # Relative information + self.years = int(years) + self.months = int(months) + self.days = days + weeks * 7 + self.leapdays = leapdays + self.hours = hours + self.minutes = minutes + self.seconds = seconds + self.microseconds = microseconds + + # Absolute information + self.year = year + self.month = month + self.day = day + self.hour = hour + self.minute = minute + self.second = second + self.microsecond = microsecond + + if any(x is not None and int(x) != x + for x in (year, month, day, hour, + minute, second, microsecond)): + # For now we'll deprecate floats - later it'll be an error. + warn("Non-integer value passed as absolute information. " + + "This is not a well-defined condition and will raise " + + "errors in future versions.", DeprecationWarning) + + if isinstance(weekday, integer_types): + self.weekday = weekdays[weekday] + else: + self.weekday = weekday + + yday = 0 + if nlyearday: + yday = nlyearday + elif yearday: + yday = yearday + if yearday > 59: + self.leapdays = -1 + if yday: + ydayidx = [31, 59, 90, 120, 151, 181, 212, + 243, 273, 304, 334, 366] + for idx, ydays in enumerate(ydayidx): + if yday <= ydays: + self.month = idx+1 + if idx == 0: + self.day = yday + else: + self.day = yday-ydayidx[idx-1] + break + else: + raise ValueError("invalid year day (%d)" % yday) + + self._fix() + + def _fix(self): + if abs(self.microseconds) > 999999: + s = _sign(self.microseconds) + div, mod = divmod(self.microseconds * s, 1000000) + self.microseconds = mod * s + self.seconds += div * s + if abs(self.seconds) > 59: + s = _sign(self.seconds) + div, mod = divmod(self.seconds * s, 60) + self.seconds = mod * s + self.minutes += div * s + if abs(self.minutes) > 59: + s = _sign(self.minutes) + div, mod = divmod(self.minutes * s, 60) + self.minutes = mod * s + self.hours += div * s + if abs(self.hours) > 23: + s = _sign(self.hours) + div, mod = divmod(self.hours * s, 24) + self.hours = mod * s + self.days += div * s + if abs(self.months) > 11: + s = _sign(self.months) + div, mod = divmod(self.months * s, 12) + self.months = mod * s + self.years += div * s + if (self.hours or self.minutes or self.seconds or self.microseconds + or self.hour is not None or self.minute is not None or + self.second is not None or self.microsecond is not None): + self._has_time = 1 + else: + self._has_time = 0 + + @property + def weeks(self): + return int(self.days / 7.0) + + @weeks.setter + def weeks(self, value): + self.days = self.days - (self.weeks * 7) + value * 7 + + def _set_months(self, months): + self.months = months + if abs(self.months) > 11: + s = _sign(self.months) + div, mod = divmod(self.months * s, 12) + self.months = mod * s + self.years = div * s + else: + self.years = 0 + + def normalized(self): + """ + Return a version of this object represented entirely using integer + values for the relative attributes. + + >>> relativedelta(days=1.5, hours=2).normalized() + relativedelta(days=+1, hours=+14) + + :return: + Returns a :class:`dateutil.relativedelta.relativedelta` object. + """ + # Cascade remainders down (rounding each to roughly nearest microsecond) + days = int(self.days) + + hours_f = round(self.hours + 24 * (self.days - days), 11) + hours = int(hours_f) + + minutes_f = round(self.minutes + 60 * (hours_f - hours), 10) + minutes = int(minutes_f) + + seconds_f = round(self.seconds + 60 * (minutes_f - minutes), 8) + seconds = int(seconds_f) + + microseconds = round(self.microseconds + 1e6 * (seconds_f - seconds)) + + # Constructor carries overflow back up with call to _fix() + return self.__class__(years=self.years, months=self.months, + days=days, hours=hours, minutes=minutes, + seconds=seconds, microseconds=microseconds, + leapdays=self.leapdays, year=self.year, + month=self.month, day=self.day, + weekday=self.weekday, hour=self.hour, + minute=self.minute, second=self.second, + microsecond=self.microsecond) + + def __add__(self, other): + if isinstance(other, relativedelta): + return self.__class__(years=other.years + self.years, + months=other.months + self.months, + days=other.days + self.days, + hours=other.hours + self.hours, + minutes=other.minutes + self.minutes, + seconds=other.seconds + self.seconds, + microseconds=(other.microseconds + + self.microseconds), + leapdays=other.leapdays or self.leapdays, + year=(other.year if other.year is not None + else self.year), + month=(other.month if other.month is not None + else self.month), + day=(other.day if other.day is not None + else self.day), + weekday=(other.weekday if other.weekday is not None + else self.weekday), + hour=(other.hour if other.hour is not None + else self.hour), + minute=(other.minute if other.minute is not None + else self.minute), + second=(other.second if other.second is not None + else self.second), + microsecond=(other.microsecond if other.microsecond + is not None else + self.microsecond)) + if isinstance(other, datetime.timedelta): + return self.__class__(years=self.years, + months=self.months, + days=self.days + other.days, + hours=self.hours, + minutes=self.minutes, + seconds=self.seconds + other.seconds, + microseconds=self.microseconds + other.microseconds, + leapdays=self.leapdays, + year=self.year, + month=self.month, + day=self.day, + weekday=self.weekday, + hour=self.hour, + minute=self.minute, + second=self.second, + microsecond=self.microsecond) + if not isinstance(other, datetime.date): + return NotImplemented + elif self._has_time and not isinstance(other, datetime.datetime): + other = datetime.datetime.fromordinal(other.toordinal()) + year = (self.year or other.year)+self.years + month = self.month or other.month + if self.months: + assert 1 <= abs(self.months) <= 12 + month += self.months + if month > 12: + year += 1 + month -= 12 + elif month < 1: + year -= 1 + month += 12 + day = min(calendar.monthrange(year, month)[1], + self.day or other.day) + repl = {"year": year, "month": month, "day": day} + for attr in ["hour", "minute", "second", "microsecond"]: + value = getattr(self, attr) + if value is not None: + repl[attr] = value + days = self.days + if self.leapdays and month > 2 and calendar.isleap(year): + days += self.leapdays + ret = (other.replace(**repl) + + datetime.timedelta(days=days, + hours=self.hours, + minutes=self.minutes, + seconds=self.seconds, + microseconds=self.microseconds)) + if self.weekday: + weekday, nth = self.weekday.weekday, self.weekday.n or 1 + jumpdays = (abs(nth) - 1) * 7 + if nth > 0: + jumpdays += (7 - ret.weekday() + weekday) % 7 + else: + jumpdays += (ret.weekday() - weekday) % 7 + jumpdays *= -1 + ret += datetime.timedelta(days=jumpdays) + return ret + + def __radd__(self, other): + return self.__add__(other) + + def __rsub__(self, other): + return self.__neg__().__radd__(other) + + def __sub__(self, other): + if not isinstance(other, relativedelta): + return NotImplemented # In case the other object defines __rsub__ + return self.__class__(years=self.years - other.years, + months=self.months - other.months, + days=self.days - other.days, + hours=self.hours - other.hours, + minutes=self.minutes - other.minutes, + seconds=self.seconds - other.seconds, + microseconds=self.microseconds - other.microseconds, + leapdays=self.leapdays or other.leapdays, + year=(self.year if self.year is not None + else other.year), + month=(self.month if self.month is not None else + other.month), + day=(self.day if self.day is not None else + other.day), + weekday=(self.weekday if self.weekday is not None else + other.weekday), + hour=(self.hour if self.hour is not None else + other.hour), + minute=(self.minute if self.minute is not None else + other.minute), + second=(self.second if self.second is not None else + other.second), + microsecond=(self.microsecond if self.microsecond + is not None else + other.microsecond)) + + def __abs__(self): + return self.__class__(years=abs(self.years), + months=abs(self.months), + days=abs(self.days), + hours=abs(self.hours), + minutes=abs(self.minutes), + seconds=abs(self.seconds), + microseconds=abs(self.microseconds), + leapdays=self.leapdays, + year=self.year, + month=self.month, + day=self.day, + weekday=self.weekday, + hour=self.hour, + minute=self.minute, + second=self.second, + microsecond=self.microsecond) + + def __neg__(self): + return self.__class__(years=-self.years, + months=-self.months, + days=-self.days, + hours=-self.hours, + minutes=-self.minutes, + seconds=-self.seconds, + microseconds=-self.microseconds, + leapdays=self.leapdays, + year=self.year, + month=self.month, + day=self.day, + weekday=self.weekday, + hour=self.hour, + minute=self.minute, + second=self.second, + microsecond=self.microsecond) + + def __bool__(self): + return not (not self.years and + not self.months and + not self.days and + not self.hours and + not self.minutes and + not self.seconds and + not self.microseconds and + not self.leapdays and + self.year is None and + self.month is None and + self.day is None and + self.weekday is None and + self.hour is None and + self.minute is None and + self.second is None and + self.microsecond is None) + # Compatibility with Python 2.x + __nonzero__ = __bool__ + + 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), + microseconds=int(self.microseconds * f), + leapdays=self.leapdays, + year=self.year, + month=self.month, + day=self.day, + weekday=self.weekday, + hour=self.hour, + minute=self.minute, + second=self.second, + microsecond=self.microsecond) + + __rmul__ = __mul__ + + def __eq__(self, other): + if not isinstance(other, relativedelta): + return NotImplemented + if self.weekday or other.weekday: + if not self.weekday or not other.weekday: + return False + if self.weekday.weekday != other.weekday.weekday: + return False + n1, n2 = self.weekday.n, other.weekday.n + if n1 != n2 and not ((not n1 or n1 == 1) and (not n2 or n2 == 1)): + return False + return (self.years == other.years and + self.months == other.months and + self.days == other.days and + self.hours == other.hours and + self.minutes == other.minutes and + self.seconds == other.seconds and + self.microseconds == other.microseconds and + self.leapdays == other.leapdays and + self.year == other.year and + self.month == other.month and + self.day == other.day and + self.hour == other.hour and + self.minute == other.minute and + self.second == other.second and + self.microsecond == other.microsecond) + + def __hash__(self): + return hash(( + self.weekday, + self.years, + self.months, + self.days, + self.hours, + self.minutes, + self.seconds, + self.microseconds, + self.leapdays, + self.year, + self.month, + self.day, + self.hour, + self.minute, + self.second, + self.microsecond, + )) + + def __ne__(self, other): + return not self.__eq__(other) + + def __div__(self, other): + try: + reciprocal = 1 / float(other) + except TypeError: + return NotImplemented + + return self.__mul__(reciprocal) + + __truediv__ = __div__ + + def __repr__(self): + l = [] + for attr in ["years", "months", "days", "leapdays", + "hours", "minutes", "seconds", "microseconds"]: + value = getattr(self, attr) + if value: + l.append("{attr}={value:+g}".format(attr=attr, value=value)) + for attr in ["year", "month", "day", "weekday", + "hour", "minute", "second", "microsecond"]: + value = getattr(self, attr) + if value is not None: + l.append("{attr}={value}".format(attr=attr, value=repr(value))) + return "{classname}({attrs})".format(classname=self.__class__.__name__, + attrs=", ".join(l)) + + +def _sign(x): + return int(copysign(1, x)) + +# vim:ts=4:sw=4:et |