For all problems you must:

-Write Python code

-Test, debug, and execute your code

-Submit a copy of your commented source code

1.

a) Complete the partial implementation of the Date class by implementing the remaining methods:

monthName(): Returns the Gregorian month name of this date.

isLeapYear(): Determines if this date falls in a leap year and returns the appropriate boolean value.

numDays(): Returns the number of days as a positive integer between this date and the otherDate.

advanceBy(): Advances the date by the given number of days. The date is incremented if days is positive and decremented if days is negative. The date is capped to November 24, 4714 BC, if necessary.

b) Add additional operations to the Date class:

--dayOfWeekName(): returns a string containing the name of the day.

--isWeekDay(): determines if the date is a weekday.

--isSolstice(): determines if the date is the summer or winter solstice.

# date.py

# Implements a proleptic Gregorian calendar date as a Julian day number.

class Date:

# Asert [ assert EXPRESSION [',' EXPRESSION ] ] will raise an error

# if the first expression is wrong. If another expression is given

# it will executed that expression in raising the error.

def __init__(self,month,day,year):

self._julianDay = 0

assert self.isValidGregorian(month,day,year),"Invalid Gregorian Date."

tmp = 0

if month < 3:

tmp = -1

self._julianDay = day - 32075 + \

(1461 * (year + 4800 + tmp) // 4 ) + \

(367 * (month - 2 - tmp *12) // 12) - \

(3 * ((year + 4900 + tmp) // 100) // 4)

def isValidGregorian(self,month,day,year):

return_code = True

if month == None or day == None or year == None:

return_code = False

if month > 12 or day > 31:

return_code = False

if month < 0 or day < 0:

return_code = False

return return_code

def month(self):

return (self._toGregorian())[0]

def day (self):

return (self._toGregorian())[1]

def year (self):

return (self._toGregorian())[2]

def dayOfWeek(self):

month,day,year = self._toGregorian()

if month < 3:

month = month +12

year = year -1

return ((13 * month + 3) // 5 + day + year + year //4 - year // 100 + year // 400) % 7

def __str__(self):

month, day, year = self._toGregorian()

return "%02d/%02d/%04d" % (month,day,year)

def __eq__ (self,otherDate):

return self._julianDay == otherDate._julianDay

def __lt__(self, otherDate):

return self._julianDay < otherDate._julianDay

def __le__(self,otherDate):

return self._julianDay <= otherDate._julianDay

def _toGregorian(self):

A = self._julianDay + 68569

B = 4 * A // 146097

A = A - (146097 * B + 3) //4

year = 4000 * (A+1) // 1461001

A = A - (1461 * year // 4) + 31

month = 80*A // 2447

day = A - (2447 * month //80)

A = month //11

month = month + 2 - (12*A)

year = 100 * (B-49) + year + A

return month,day,year

# main_date.py

# Extracts a collection of birth dates from the user and determines

# if each individual is at least 21 years of age.

from date import Date

def main():

# Date before which a person must have been born to be 21 or older.

bornBefore = Date(9, 9, 1994)

# Extract birth dates from the user and determine if 21 or older.

date = promptAndExtractDate()

while date is not None :

if date <= bornBefore :

print( "Is at least 21 years of age: ", date )

else :

print( "You are too young!")

date = promptAndExtractDate()

# Prompts for and extracts the Gregorian date components. Returns a

# Date object or None when the user has finished entering dates.

def promptAndExtractDate():

print( "Enter a birth date." )

month = int( input("month (0 to quit): ") )

if month == 0 :

return None

else :

day = int( input("day: ") )

year = int( input("year: ") )

return Date( month, day, year )

# Call the main routine.

main()