Find months with at least 5 Fridays, Saturdays and Sundays

gistfile1.py

import datetime
import calendar

START_YEAR = 1900
END_YEAR = 2020

def get_all_super_months(start_year, end_year):
	'''find all months with at least 5 fridays, saturdays and sundays'''

	super_months = []

	for year in range(start_year, end_year):
		for month in range(1, 12):
			this_month = {}
	
			month_calendar = calendar.Calendar()
			for day in month_calendar.itermonthdates(year, month):
			
				# itermonthdates returns also days from previous and next month to complete the week
				# http://docs.python.org/library/calendar.html
				if day.month != month:
					continue
				
				weekday = day.weekday()
			
				if weekday not in this_month:
					this_month[weekday] = 0
				this_month[weekday] = this_month[weekday] + 1	
			
			# now check if that was super-month
			if this_month[4] >= 5 and this_month[5] >= 5 and this_month[6] >= 5:
				super_months.append((year, month))
	
	return super_months

def print_stats(start_year, end_year, super_months):
	'''find out how many were there, and print them'''
	
	print "From year %d to year %d, I have found %d super-months\n" % (start_year, end_year, len(super_months))
	print "List of super-months:\n"
	for sm in super_months:
		print "%s %s\n" % (str(sm[0]), str(sm[1]))
		
def count_non_super_years(start_year, end_year, super_months):
	non_super_years = []
	for year in range(start_year, end_year):
		occurences_for_year = [y for (y, m) in super_months if y == year]
		
		#print "occ: ", occurences_for_year
		
		if occurences_for_year < 1:
			non_super_years.append(year)
	
	if len(non_super_years) == 0:
		print "All years have at least 1 super month!"
	else:
		print "Years without super month: ", non_super_years

if __name__ == '__main__':
	super_months = get_all_super_months(START_YEAR, END_YEAR)
	count_non_super_years(START_YEAR, END_YEAR, super_months)
	#print_stats(START_YEAR, END_YEAR, super_months)