nepali_calendar.py

#!/usr/bin/env python
# -*- coding: UTF-8 -*-

import sys
import datetime
import os
import subprocess

### BEGIN LICENSE
# Copyright (C) 2011 Shritesh Bhattarai shriteshb@gmail.com
# This program is free software: you can redistribute it and/or modify it 
# under the terms of the GNU General Public License version 3, as published 
# by the Free Software Foundation.
# 
# This program is distributed in the hope that it will be useful, but 
# WITHOUT ANY WARRANTY; without even the implied warranties of 
# MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR 
# PURPOSE.  See the GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License along 
# with this program.  If not, see <http://www.gnu.org/licenses/>.
### END LICENSE

class NepaliDateConverter:
    '''
    A class to convert Bikram Samwat (B.S.) to A.D. and vice versa.
    
    Usage:
    converter = NepaliDateConverter()
    print converter.ad2bs((1995,9,12))
    print converter.bs2ad((2052,05,27))
    
    Range:
    1944/4/1 A.D. to 2043/4/13 A.D.
    2000/9/17 B.S. to 2099/12/20 B.S.
    
    bs : a dictionary that contains the number of days in each month of the B.S. year
    bs_equiv, ad_equiv  : The B.S. and A.D. equivalent dates for counting and calculation
    
    '''
    
    (bs_equiv, ad_equiv) = ((2000,9,17),(1944,1,1)) 
    
    bs = {} 
    bs[2000]=(30,32,31,32,31,30,30,30,29,30,29,31)
    bs[2001]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2002]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2003]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2004]=(30,32,31,32,31,30,30,30,29,30,29,31)
    bs[2005]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2006]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2007]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2008]=(31,31,31,32,31,31,29,30,30,29,29,31)
    bs[2009]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2010]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2011]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2012]=(31,31,31,32,31,31,29,30,30,29,30,30)
    bs[2013]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2014]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2015]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2016]=(31,31,31,32,31,31,29,30,30,29,30,30)
    bs[2017]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2018]=(31,32,31,32,31,30,30,29,30,29,30,30)
    bs[2019]=(31,32,31,32,31,30,30,30,29,30,29,31)
    bs[2020]=(31,31,31,32,31,31,30,29,30,29,30,30)
    bs[2021]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2022]=(31,32,31,32,31,30,30,30,29,29,30,30)
    bs[2023]=(31,32,31,32,31,30,30,30,29,30,29,31)
    bs[2024]=(31,31,31,32,31,31,30,29,30,29,30,30)
    bs[2025]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2026]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2027]=(30,32,31,32,31,30,30,30,29,30,29,31)
    bs[2028]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2029]=(31,31,32,31,32,30,30,29,30,29,30,30)
    bs[2030]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2031]=(30,32,31,32,31,30,30,30,29,30,29,31)
    bs[2032]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2033]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2034]=(31,32,31,32,31,30,30,30,29,29,30,31) 
    bs[2035]=(30,32,31,32,31,31,29,30,30,29,29,31)
    bs[2036]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2037]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2038]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2039]=(31,31,31,32,31,31,29,30,30,29,30,30)
    bs[2040]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2041]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2042]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2043]=(31,31,31,32,31,31,29,30,30,29,30,30)
    bs[2044]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2045]=(31,32,31,32,31,30,30,29,30,29,30,30)
    bs[2046]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2047]=(31,31,31,32,31,31,30,29,30,29,30,30)
    bs[2048]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2049]=(31,32,31,32,31,30,30,30,29,29,30,30)
    bs[2050]=(31,32,31,32,31,30,30,30,29,30,29,31)
    bs[2051]=(31,31,31,32,31,31,30,29,30,29,30,30)
    bs[2052]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2053]=(31,32,31,32,31,30,30,30,29,29,30,30)
    bs[2054]=(31,32,31,32,31,30,30,30,29,30,29,31)
    bs[2055]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2056]=(31,31,32,31,32,30,30,29,30,29,30,30)
    bs[2057]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2058]=(30,32,31,32,31,30,30,30,29,30,29,31)
    bs[2059]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2060]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2061]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2062]=(30,32,31,32,31,31,29,30,29,30,29,31)
    bs[2063]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2064]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2065]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2066]=(31,31,31,32,31,31,29,30,30,29,29,31)
    bs[2067]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2068]=(31,31,32,32,31,30,30,29,30,29,30,30)
    bs[2069]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2070]=(31,31,31,32,31,31,29,30,30,29,30,30)
    bs[2071]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2072]=(31,32,31,32,31,30,30,29,30,29,30,30)
    bs[2073]=(31,32,31,32,31,30,30,30,29,29,30,31)
    bs[2074]=(31,31,31,32,31,31,30,29,30,29,30,30)
    bs[2075]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2076]=(31,32,31,32,31,30,30,30,29,29,30,30)
    bs[2077]=(31,32,31,32,31,30,30,30,29,30,29,31)
    bs[2078]=(31,31,31,32,31,31,30,29,30,29,30,30)
    bs[2079]=(31,31,32,31,31,31,30,29,30,29,30,30)
    bs[2080]=(31,32,31,32,31,30,30,30,29,29,30,30)
    bs[2081]=(31,31,32,32,31,30,30,30,29,30,30,30)
    bs[2082]=(30,32,31,32,31,30,30,30,29,30,30,30)
    bs[2083]=(31,31,32,31,31,30,30,30,29,30,30,30)
    bs[2084]=(31,31,32,31,31,30,30,30,29,30,30,30)
    bs[2085]=(31,32,31,32,30,31,30,30,29,30,30,30)
    bs[2086]=(30,32,31,32,31,30,30,30,29,30,30,30)
    bs[2087]=(31,31,32,31,31,31,30,30,29,30,30,30)
    bs[2088]=(30,31,32,32,30,31,30,30,29,30,30,30)
    bs[2089]=(30,32,31,32,31,30,30,30,29,30,30,30)
    bs[2090]=(30,32,31,32,31,30,30,30,29,30,30,30)
    bs[2091]=(31,31,32,31,31,31,30,30,29,30,30,30)
    bs[2092]=(30,31,32,32,31,30,30,30,29,30,30,30)
    bs[2093]=(30,32,31,32,31,30,30,30,29,30,30,30)
    bs[2094]=(31,31,32,31,31,30,30,30,29,30,30,30)
    bs[2095]=(31,31,32,31,31,31,30,29,30,30,30,30)
    bs[2096]=(30,31,32,32,31,30,30,29,30,29,30,30)
    bs[2097]=(31,32,31,32,31,30,30,30,29,30,30,30)
    bs[2098]=(31,31,32,31,31,31,29,30,29,30,29,31)
    bs[2099]=(31,31,32,31,31,31,30,29,29,30,30,30)
    
    def date_from_tuple(self,tuple_to_convert):
        '''
        Returns the given tuple as datetime.date object
        
        tuple_to_convert : A tuple in the format (year,month,day)
        
        '''
        (year, month, day) = tuple_to_convert
        return datetime.date(year,month,day)
    
    def tuple_from_date(self,date_to_convert):
        '''
        Returns the given date object as tuple in the format (year,month,day)
        
        date_to_convert : A date object
        
        '''
        (year, month, day)  = (date_to_convert.year, date_to_convert.month, date_to_convert.day)
        return (year, month, day)
    
    def count_ad_days(self,begin_ad_date,end_ad_date):
        '''
        Returns the number of days between the two given A.D. dates.
    
        begin_ad_date : A tuple in the format (year,month,day) that specify the date to start counting from.
        end_ad_date : A tuple in the format (year,month,day) that specify the date to end counting.
        
        '''
        date_begin = self.date_from_tuple(begin_ad_date)
        date_end = self.date_from_tuple(end_ad_date)
        delta = date_end - date_begin
        return delta.days
    
    def count_bs_days(self,begin_bs_date,end_bs_date):
        '''
        Returns the number of days between the two given B.S. dates.
    
        begin_ad_date : A tuple in the format (year,month,day) that specify the date to start counting from.
        end_ad_date : A tuple in the format (year,month,day) that specify the date to end counting.
        
        Algorithm:
        
        Its not the piece of algorithm, but it works for this program..
        
        1) First add total days in all the years
            
        2) Subtract the days from first (n-1) months of the beginning year 
        
        3) Add the number of days from the last month of the beginning year
             
        4) Subtract the days from the last months from the end year
        
        5) Add the beginning days excluding the day itself
        
        6) Add the last remaining days excluding the day itself
            
         
        NOTE:
        Tuple in the dictionary starts from 0
        The range(a,b) function starts from a and ends at b-1
        '''
        begin_year, begin_month, begin_day =  begin_bs_date
        end_year, end_month, end_day = end_bs_date
        days = 0            
        #1) First add total days in all the years
        for year in range(begin_year, end_year + 1):  
            for days_in_month in self.bs[year]:
                days = days + days_in_month
        #2) Subtract the days from first (n-1) months of the beginning year
        for month in range(0,begin_month):
            days = days - self.bs[begin_year][month]
        #3) Add the number of days from the last month of the beginning year
        days = days + self.bs[begin_year][12-1]
        #4) Subtract the days from the last months from the end year
        for month in range(end_month - 1,12):
            days = days - self.bs[end_year][month]
        #5) Add the beginning days excluding the day itself
        days = days - begin_day - 1
        #5) Add the last remaining days excluding the day itself
        days = days + end_day - 1
        return days
        
    def add_ad_days(self,ad_date,num_days):
        '''
        Adds the given number of days to the given A.D. date and returns it as a tuple in the format (year,month,day)
        
        ad_date : A tuple in the format (year,month,day) 
        num_days : Number of days to add to the given date
         
        '''
        date = self.date_from_tuple(ad_date)
        day = datetime.timedelta(days=num_days)
        return self.tuple_from_date(date + day)
    
    def add_bs_days(self,bs_date,num_days):
        '''
        Adds the given number of days to the given B.S. date and returns it as a tuple in the format (year,month,day)
        
        bs_date : a tuple in the format (year,month,day) 
        num_days : Number of days to add to the given date
         
        Algorithm: 
        1) Add the total number of days to the original days
        
        2) Until the number of days becomes applicable to the current month, subtract the days by the number of days in the current month and increase the month
            
        3) If month reaches 12, increase the year by 1 and set the month to 1
            
        Note:
        Tuple in the dictionary starts from 0
        '''
        (year, month, day) = bs_date
        #1) Add the total number of days to the original days
        day = day + num_days
        #2) Until the number of days becomes applicable to the current month, subtract the days by the number of days in the current month and increase the month
        while day > self.bs[year][month - 1]:
            day = day - self.bs[year][month- 1]
            month = month + 1
            #3) If month reaches 12, increase the year by 1 and set the month to 1
            if month > 12:
                month = 1
                year = year + 1
        return (year, month, day)
    
    def bs2ad(self,bs_date):
        '''
        Returns the A.D. equivalent date as a tuple in the format (year,month,day) if the date is within range, else returns None
        
        bs_date : A tuple in the format (year,month,day)
              
        '''
        (year, month, day) = bs_date
        if year < 2000 or year > 2099 or month < 1 or month > 12 or day < 1 or day > 32:
            return None
        else:
            if year == 2000 and month == 9 and day < 17:
                return None
            else:
                date_delta = self.count_bs_days(self.bs_equiv, bs_date)
                return self.add_ad_days(self.ad_equiv, date_delta)
    
    def ad2bs(self,ad_date):
        '''
        Returns the B.S. equivalent date as a tuple in the format (year,month,day) if the date is within range, else returns None
        
        bs_date : An tuple in the format (year,month,day)
        '''
        (year, month, day) = ad_date
        if year < 1944 or year > 2043 or month < 1 or month > 12 or day < 1 or day > 31:
            return None
        else:
            if year == 2043 and month == 4 and day > 13:
                return None
            else:
                date_delta = self.count_ad_days(self.ad_equiv, ad_date)
                return self.add_bs_days(self.bs_equiv, date_delta)

    def eng2nepnum(self,n):
        nums = {"0":"०","1":"१","2":"२","3":"३","4":"४","5":"५","6":"६","7":"७","8":"८","9":"९"}
        numstr = str(n)    
        s = ""
        for ch in numstr:
            s += nums[ch]
            
        return s
    
    def today_en_date(self):
        nw = datetime.datetime.now()
        return "(%s, %s, %s)" %(nw.year,nw.month,nw.day)
        
    def contents_func(self):
        converter = NepaliDateConverter()
        now = datetime.datetime.now()
        (y,m,d)= converter.ad2bs((now.year, now.month, now.day))
        day = now.strftime("%a")
    
        nepday = {'Sun': 'आइतवार', 'Mon': 'सोमवार', 'Tue':'मंगलवार',
                    'Wed':'बुधवार', 'Thu': 'बिहिवार', 'Fri': 'शुक्रवार', 'Sat': 'शनिवार'}
        
        if day in nepday:
            nd = nepday[day]
        
        nepmonths = {1: "बैशाख", 2: "ज्येष्ठ", 3: "आषाढ", 4:"श्रावण", 5:"भाद्र", 6:"आश्विन",
                    7:"कार्तिक", 8:"मंसिर", 9:"पौष", 10:"माघ", 11:"फाल्गुन", 12:"चैत्र"}
        
        return " %s %s %s, %s" %(self.eng2nepnum(y), nepmonths[m], self.eng2nepnum(d), nd)