lunisolar 0.1.3

A library to handle the Chinese calendar

Lunisolar is a Python package for handling Chinese calendars. Lunisolar contains a set of helper functions designed to make it easy to convert between the Gregorian (Western) calendar and the Chinese calendar.

Based on the works of Helmer Aslaksen. Built on top of PyCalCal, the Python implementation of Calendrica 3.0, a set of calendar-related algorithms as described in Dershowitz and Reingold’s book “Calendrical Calculations”.

Usage

Initializing a Chinese date:

>>> from lunisolar import ChineseDate
>>> mid_autumn = ChineseDate.from_chinese(chinese_year=2013,
                                          chinese_month=8,
                                          chinese_day=15,
                                          is_leap_month=False)
>>> mid_autumn
chinese_date(year=2013, month=8, day=15, is_leap_month=False)
>>> mid_autumn.gregorian_date
datetime.date(2013, 9, 19)

A Chinese date object can be initialized from a Gregorian (western) date:

>>> from lunisolar import ChineseDate
>>> moon_landing = ChineseDate.from_gregorian(1969, 7, 20)
>>> moon_landing
chinese_date(year=1969, month=6, day=7, is_leap_month=False)

The ChineseDate class shares the same constructors as datetime.date:

>>> ChineseDate.today()
chinese_date(year=2012, month=12, day=29, is_leap_month=False)

>>> timestamp = 1360414893.724195
>>> ChineseDate.fromtimestamp(timestamp)
chinese_date(year=2012, month=12, day=29, is_leap_month=False)

>>> ordinal = 734908
>>> ChineseDate.fromordinal(ordinal)
chinese_date(year=2012, month=12, day=29, is_leap_month=False)

Retrieving properties of the Chinese calendar:

>>> moon_landing = ChineseDate.from_gregorian(1969, 7, 20)
>>> moon_landing.year
1969
>>> moon_landing.month
6
>>> moon_landing.day
7
>>> moon_landing.is_leap_month
False
>>> moon_landing.zodiac
rooster
>>> moon_landing.element
earth
>>> moon_landing.heavenly_stem
ji
>>> moon_landing.earthly_branch
you

The add, subtract, and comparison operators for ChineseDate is similar to that of the datetime.date object. For subtraction and comparison, ChineseDate and datetime.date can be used interchangeably.

>>> from datetime import timedelta
>>> cdate = ChineseDate.from_gregorian(1969, 7, 20)
>>> gdate = datetime.date(2013, 2, 10)
>>> cdate > gdate
False
>>> gdate - cdate
datetime.timedelta(15911)
>>> diff = timedelta(200)
>>> cdate + diff
chinese_date(year=1969, month=12, day=29, is_leap_month=False)