Programming Assignment 1 (Date Arithmetic)

1. Complete the specification of the Date class as defined below. You are not allowed to use any library packages within Python except in implementing the today() class method.

   from datetime import date
   import math
   
   class Date:
   	# Constructor
   	def __init__(self, m, d, y):
   		self.month = m
   		self.day = d
   		self.year = y
   
   	def leap_year(self):
   		return ((self.year%4 == 0) and not (self.year%100 == 0 and self.year%400 != 0))
   
   	# To implement this class method, you can use Python's datetime package
   	@classmethod
   	def today(cls):
   		pass
   
   	# https://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week
   	# Gauss - disparate variation
   	# returns day of week as a String ("Sunday", "Monday", ...)
   	def day_of_weekS(self):
   		pass
   
   	# returns day of week as a number (0 for "Sunday", 1 for "Monday", ...)
   	def day_of_weekN(self):
   		pass
   
   	# Returns the Date object one day after self
   	def tomorrow(self):
   		pass
   
   	# Returns the Date object obtained by adding ndays to self
   	def add(self,ndays):
   		pass
   
   	# Returns True if self is after d
   	def after(self,d):
   		pass
   
   	# Returns True if self is same as d
   	def equals(self,d):
   		pass
   
   	# Returns True if self is before d
   	def before(self,d):
   		pass
   
   	# Returns the number of days between self and d
   	def days_between(self,d):
   		pass
   
   	# Please look at part 2 of assignment for string format
   	def __str__(self):
   		pass
   

   The above template for Date class is available in Date.py.

2. Write a program, called DateArithmetic.py, which reads data from an input file (file name provided as command line input) containing information about celebrities including their date of birth and if no longer alive their date of death. A sample input (available in text file p1.dat) is given below:

   mac-mini:p1-date raj$ more p1.dat
   Albert:Einstein:3/14/1879:4/18/1955
   Donald:Knuth:1/10/1938:
   Srinivasa:Ramanujan:12/22/1887:4/26/1920
   Isaac:Newton:12/25/1642:3/20/1726
   Tim:Berners-Lee:6/8/1955:
   Alonzo:Church:8/11/1995:6/14/1903
   Alan:Turing:6/23/1912:6/7/1954
   Leonhard:Euler:4/15/1707:9/18/1783
   Jimi:Hendrix:11/27/1942:9/18/1970
   Bob:Marley:2/6/1945:5/11/1981
   

   Each line in the file contains the first name, last name, date of birth, and date of death (if alive this part will be blank) of celebrities. It is possible for error in data entry in this file in that the date of birth may be AFTER date of death. Such an error should be flagged by your program and the entry discarded from further calculations. We can assume that besides this error the input data does not contain any other error such as invalid day, month, or year in the dates.

   The program should process this information and produce a listing of celebrity information as shown in the sample run (sorted by NUM_DAYS in increasing order).

   A sample run is shown below:

   mac-mini:p1-date raj$ python3 P1.py p1.dat 
   BAD DATA: Alonzo:Church:8/11/1995:6/14/1903
   
   FNAME        LNAME        DOB                  DAY        DOD                  DAY        NUM_DAYS  
   ---------------------------------------------------------------------------------------------------
   Jimi         Hendrix      27 November, 1942    Friday     18 September, 1970   Friday      10157
   Srinivasa    Ramanujan    22 December, 1887    Thursday   26 April, 1920       Monday      11813
   Bob          Marley       6 February, 1945     Tuesday    11 May, 1981         Monday      13243
   Alan         Turing       23 June, 1912        Sunday     7 June, 1954         Monday      15324
   Tim          Berners-Lee  8 June, 1955         Wednesday  None                 ALIVE       25052
   Albert       Einstein     14 March, 1879       Friday     18 April, 1955       Monday      27793
   Leonhard     Euler        15 April, 1707       Friday     18 September, 1783   Thursday    27915
   Isaac        Newton       25 December, 1642    Thursday   20 March, 1726       Wednesday   30400
   Donald       Knuth        10 January, 1938     Monday     None                 ALIVE       31410
   ---------------------------------------------------------------------------------------------------
   

   The program should use the Date class developed earlier to do any Date calculations. The formatting should be exactly as shown. You will notice the output contains the date of birth and date of death (if applicable) in a different format. Also there are three new columns in the output: day of week for DOB, day of week for DOD, and number of days alive. For celebrities alive as of today, the number of days alive will be from DOB till today!

Submit source files (Date.py and DateArithmetic.py).