# this file is derived from lunar project. # # lunar project: # Copyright (C) 1988,1989,1991,1992,2001 Fung F. Lee and Ricky Yeung # Licensed under GPLv2. # # Copyright (C) 2008 LI Daobing ''' A Chinese Calendar Library in Pure Python ========================================= Chinese Calendar: http://en.wikipedia.org/wiki/Chinese_calendar Usage ----- >>> LunarDate.fromSolarDate(1976, 10, 1) LunarDate(1976, 8, 8, 1) >>> LunarDate(1976, 8, 8, 1).toSolarDate() datetime.date(1976, 10, 1) >>> LunarDate(1976, 8, 8, 1).year 1976 >>> LunarDate(1976, 8, 8, 1).month 8 >>> LunarDate(1976, 8, 8, 1).day 8 >>> LunarDate(1976, 8, 8, 1).isLeapMonth True >>> today = LunarDate.today() >>> type(today).__name__ 'LunarDate' >>> # support '+' and '-' between datetime.date and datetime.timedelta >>> ld = LunarDate(1976,8,8) >>> sd = datetime.date(2008,1,1) >>> td = datetime.timedelta(days=10) >>> ld-ld datetime.timedelta(0) >>> ld-sd datetime.timedelta(-11444) >>> ld-td LunarDate(1976, 7, 27, 0) >>> sd-ld datetime.timedelta(11444) >>> ld+td LunarDate(1976, 8, 18, 0) >>> td+ld LunarDate(1976, 8, 18, 0) >>> ld2 = LunarDate.today() >>> ld < ld2 True >>> ld <= ld2 True >>> ld > ld2 False >>> ld >= ld2 False >>> ld == ld2 False >>> ld != ld2 True >>> ld == ld True News ---- * 0.1.4: support '+', '-' and compare, fix bug in year 2050 * 0.1.3: support python 3.0 Limits ------ this library can only deal with year from 1900 to 2049 (in chinese calendar). See also -------- * lunar: http://packages.qa.debian.org/l/lunar.html, A converter written in C, this program is derived from it. * python-lunar: http://code.google.com/p/liblunar/ Another library written in C, including a python binding. ''' import datetime __version__ = "$Rev: 22 $" __all__ = ['LunarDate'] class LunarDate(object): _startDate = datetime.date(1900, 1, 31) def __init__(self, year, month, day, isLeapMonth=False): self.year = year self.month = month self.day = day self.isLeapMonth = bool(isLeapMonth) def __str__(self): return 'LunarDate(%d, %d, %d, %d)' % (self.year, self.month, self.day, self.isLeapMonth) __repr__ = __str__ @staticmethod def fromSolarDate(year, month, day): ''' >>> LunarDate.fromSolarDate(1900, 1, 31) LunarDate(1900, 1, 1, 0) >>> LunarDate.fromSolarDate(2008, 10, 2) LunarDate(2008, 9, 4, 0) >>> LunarDate.fromSolarDate(1976, 10, 1) LunarDate(1976, 8, 8, 1) >>> LunarDate.fromSolarDate(2033, 10, 23) LunarDate(2033, 10, 1, 0) ''' solarDate = datetime.date(year, month, day) offset = (solarDate - LunarDate._startDate).days return LunarDate._fromOffset(offset) def toSolarDate(self): ''' >>> LunarDate(1900, 1, 1).toSolarDate() datetime.date(1900, 1, 31) >>> LunarDate(2008, 9, 4).toSolarDate() datetime.date(2008, 10, 2) >>> LunarDate(1976, 8, 8, 1).toSolarDate() datetime.date(1976, 10, 1) >>> LunarDate(2004, 1, 30).toSolarDate() Traceback (most recent call last): ... ValueError: day out of range >>> LunarDate(2050, 1, 1).toSolarDate() Traceback (most recent call last): ... ValueError: year out of range [1900, 2050) >>> ''' def _calcDays(yearInfo, month, day, isLeapMonth): isLeapMonth = int(isLeapMonth) res = 0 ok = False for _month, _days, _isLeapMonth in self._enumMonth(yearInfo): if (_month, _isLeapMonth) == (month, isLeapMonth): if 1 <= day <= _days: res += day - 1 return res else: raise ValueError("day out of range") res += _days raise ValueError("month out of range") offset = 0 if self.year < 1900 or self.year >= 2050: raise ValueError('year out of range [1900, 2050)') yearIdx = self.year - 1900 for i in range(yearIdx): offset += yearDays[i] offset += _calcDays(yearInfos[yearIdx], self.month, self.day, self.isLeapMonth) return self._startDate + datetime.timedelta(days=offset) def __sub__(self, other): if isinstance(other, LunarDate): return self.toSolarDate() - other.toSolarDate() elif isinstance(other, datetime.date): return self.toSolarDate() - other elif isinstance(other, datetime.timedelta): res = self.toSolarDate() - other return LunarDate.fromSolarDate(res.year, res.month, res.day) raise TypeError def __rsub__(self, other): if isinstance(other, datetime.date): return other - self.toSolarDate() def __add__(self, other): if isinstance(other, datetime.timedelta): res = self.toSolarDate() + other return LunarDate.fromSolarDate(res.year, res.month, res.day) raise TypeError def __radd__(self, other): return self + other def __lt__(self, other): return self - other < datetime.timedelta(0) def __le__(self, other): return self - other <= datetime.timedelta(0) @classmethod def today(cls): res = datetime.date.today() return cls.fromSolarDate(res.year, res.month, res.day) @staticmethod def _enumMonth(yearInfo): months = [(i, 0) for i in range(1, 13)] leapMonth = yearInfo % 16 if leapMonth == 0: pass elif leapMonth <= 12: months.insert(leapMonth, (leapMonth, 1)) else: raise ValueError("yearInfo %r mod 16 should in [0, 12]" % yearInfo) for month, isLeapMonth in months: if isLeapMonth: days = (yearInfo >> 16) % 2 + 29 else: days = (yearInfo >> (16 - month)) % 2 + 29 yield month, days, isLeapMonth @classmethod def _fromOffset(cls, offset): def _calcMonthDay(yearInfo, offset): for month, days, isLeapMonth in cls._enumMonth(yearInfo): if offset < days: break offset -= days return (month, offset + 1, isLeapMonth) offset = int(offset) for idx, yearDay in enumerate(yearDays): if offset < yearDay: break offset -= yearDay year = 1900 + idx yearInfo = yearInfos[idx] month, day, isLeapMonth = _calcMonthDay(yearInfo, offset) return LunarDate(year, month, day, isLeapMonth) yearInfos = [ # /* encoding: # b bbbbbbbbbbbb bbbb # bit# 1 111111000000 0000 # 6 543210987654 3210 # . ............ .... # month# 000000000111 # M 123456789012 L # # b_j = 1 for long month, b_j = 0 for short month # L is the leap month of the year if 1<=L<=12; NO leap month if L = 0. # The leap month (if exists) is long one iff M = 1. # */ 0x04bd8, # /* 1900 */ 0x04ae0, 0x0a570, 0x054d5, 0x0d260, 0x0d950,# /* 1905 */ 0x16554, 0x056a0, 0x09ad0, 0x055d2, 0x04ae0,# /* 1910 */ 0x0a5b6, 0x0a4d0, 0x0d250, 0x1d255, 0x0b540,# /* 1915 */ 0x0d6a0, 0x0ada2, 0x095b0, 0x14977, 0x04970,# /* 1920 */ 0x0a4b0, 0x0b4b5, 0x06a50, 0x06d40, 0x1ab54,# /* 1925 */ 0x02b60, 0x09570, 0x052f2, 0x04970, 0x06566,# /* 1930 */ 0x0d4a0, 0x0ea50, 0x06e95, 0x05ad0, 0x02b60,# /* 1935 */ 0x186e3, 0x092e0, 0x1c8d7, 0x0c950, 0x0d4a0,# /* 1940 */ 0x1d8a6, 0x0b550, 0x056a0, 0x1a5b4, 0x025d0,# /* 1945 */ 0x092d0, 0x0d2b2, 0x0a950, 0x0b557, 0x06ca0,# /* 1950 */ 0x0b550, 0x15355, 0x04da0, 0x0a5d0, 0x14573,# /* 1955 */ 0x052d0, 0x0a9a8, 0x0e950, 0x06aa0, 0x0aea6,# /* 1960 */ 0x0ab50, 0x04b60, 0x0aae4, 0x0a570, 0x05260,# /* 1965 */ 0x0f263, 0x0d950, 0x05b57, 0x056a0, 0x096d0,# /* 1970 */ 0x04dd5, 0x04ad0, 0x0a4d0, 0x0d4d4, 0x0d250,# /* 1975 */ 0x0d558, 0x0b540, 0x0b5a0, 0x195a6, 0x095b0,# /* 1980 */ 0x049b0, 0x0a974, 0x0a4b0, 0x0b27a, 0x06a50,# /* 1985 */ 0x06d40, 0x0af46, 0x0ab60, 0x09570, 0x04af5,# /* 1990 */ 0x04970, 0x064b0, 0x074a3, 0x0ea50, 0x06b58,# /* 1995 */ 0x05ac0, 0x0ab60, 0x096d5, 0x092e0, 0x0c960,# /* 2000 */ 0x0d954, 0x0d4a0, 0x0da50, 0x07552, 0x056a0,# /* 2005 */ 0x0abb7, 0x025d0, 0x092d0, 0x0cab5, 0x0a950,# /* 2010 */ 0x0b4a0, 0x0baa4, 0x0ad50, 0x055d9, 0x04ba0,# /* 2015 */ 0x0a5b0, 0x15176, 0x052b0, 0x0a930, 0x07954,# /* 2020 */ 0x06aa0, 0x0ad50, 0x05b52, 0x04b60, 0x0a6e6,# /* 2025 */ 0x0a4e0, 0x0d260, 0x0ea65, 0x0d530, 0x05aa0,# /* 2030 */ 0x076a3, 0x096d0, 0x04afb, 0x04ad0, 0x0a4d0,# /* 2035 */ 0x1d0b6, 0x0d250, 0x0d520, 0x0dd45, 0x0b5a0,# /* 2040 */ 0x056d0, 0x055b2, 0x049b0, 0x0a577, 0x0a4b0,# /* 2045 */ 0x0aa50, 0x1b255, 0x06d20, 0x0ada0 # /* 2049 */ ] def yearInfo2yearDay(yearInfo): '''calculate the days in a lunar year from the lunar year's info >>> yearInfo2yearDay(0) # no leap month, and every month has 29 days. 348 >>> yearInfo2yearDay(1) # 1 leap month, and every month has 29 days. 377 >>> yearInfo2yearDay((2**12-1)*16) # no leap month, and every month has 30 days. 360 >>> yearInfo2yearDay((2**13-1)*16+1) # 1 leap month, and every month has 30 days. 390 >>> # 1 leap month, and every normal month has 30 days, and leap month has 29 days. >>> yearInfo2yearDay((2**12-1)*16+1) 389 ''' yearInfo = int(yearInfo) res = 29 * 12 leap = False if yearInfo % 16 != 0: leap = True res += 29 yearInfo //= 16 for i in range(12 + leap): if yearInfo % 2 == 1: res += 1 yearInfo //= 2 return res yearDays = [yearInfo2yearDay(x) for x in yearInfos] def day2LunarDate(offset): offset = int(offset) res = LunarDate() for idx, yearDay in enumerate(yearDays): if offset < yearDay: break offset -= yearDay res.year = 1900 + idx if __name__ == '__main__': import doctest doctest.testmod()