Determine months with 5 or more Sundays using Calendar module in Python?

Question

I need to write a code to find which month in a year 2018 for example has 5 or more Sundays? I want to use calendar module in Python and save the resulting months in abbreviated form. I saw documentation for calendar module but couldnt figure out the code.

Answer 1

Here's one way. And also, go back to https://docs.python.org/3/library/calendar.html and try playing around with some of the things described in it.

import calendar

def find_five_sunday_months(year):
    calendar.setfirstweekday(calendar.SUNDAY)
    five_sunday_months = []
    for month in range(1, 13):
        calendar_month = calendar.monthcalendar(year, month)
        # If you're counting Sunday as the first day of the week, then any month that extends into
        # six weeks, or starts on a Sunday and extends into five weeks, will contain five Sundays.
        if len(calendar_month) == 6 or (len(calendar_month) == 5 and calendar_month[0][0] == 1):
            five_sunday_months.append(calendar.month_abbr[month])

    return five_sunday_months

print (find_five_sunday_months(2018))

Answer 2

Thanks @TaneTachyon for the document link you shared. It helped me lot for exploring the calendar module.

I have come up with below code for the same task.
I know it's a bit long, but for a beginner, logic and learning to use different functions, this helped me a lot:

import calendar

calendar.setfirstweekday(calendar.SUNDAY)

year = 2018
a = ()
Sun_month = []
leap = calendar.isleap(year)

for i in range(1,13):
    a = calendar.monthrange(year, i)
    #print(a[1])
    if a[1] == 30:
       if (a[0] == 5 or a[0] == 6):
           s = calendar.month_abbr[i]
           Sun_month.append(s)
    elif a[1] == 31:
       if (a[0] == 4 or a[0] == 5 or a[0] == 6):
           s = calendar.month_abbr[i]
           Sun_month.append(s)
    elif leap == True:
       if (a[0] == 6):
           s = calendar.month_abbr[i]
           Sun_month.append(s)
print("The months having >= 5 sundays in  {} is".format(year))
print(Sun_month)

Answer 3

import calendar as c    
a = []  
for i in range(1,13):  
    a.append(list(c.monthrange(2018,i)))  

b = c.month_abbr[1:13]
c = []  
for i in range(0,12):
    if (a[i][0]>4  and a[i][1]==30) or (a[i][0]>=4 and a[i][1]==31):      
        c.append(b[i])   
print(c)

Answer 4

import calendar

# here all the weeks are set to start from sunday for every month
calendar.setfirstweekday(calendar.SUNDAY)
l = list()  # empty list
# the range will be from 1 to 12
for month in range(1, 13):
    # for each month in 2018 month calendar is created
    calendar_month = calendar.monthcalendar(2018, month)
    # to count no.of sundays present in each month
    c = 0
    # len(calendar_month) for number of rows(i.e. weeks) in the month
    for i in range(len(calendar_month)):
        # calendar_month[i][0] first day(i.e. sunday) of ith week which is 
        #sunday if date is greater than 0
        if calendar_month[i][0] > 0:

            c += 1  # each sunday is counted
    if c == 5:
        # calendar.month_abbr[month] abbreviated form of month with 5 sundays 
        #is added to the list
        l.append(calendar.month_abbr[month])
print(l)

Answer 5

#With Explanation

import calendar

def find_five_sunday_months(year):
    calendar.setfirstweekday(calendar.SUNDAY)
    
    five_sunday_months = []
    for month in range(1, 13):
        calendar_month = calendar.monthcalendar(year, month)
        print('--------------------------------------------------------------------------------')
        print('month :',calendar.month_name[month])
        print('Count returned tuple as no. of weeks in a month :',calendar_month)
        print('No. of weeks in a month:',len(calendar_month))
        print('if we have 5 weeks and 5 sundays,it should print 1 else 0 :',calendar_month[0][0])
        
        # If you're counting Sunday as the first day of the week, then any month that extends into
        # six weeks, or starts on a Sunday and extends into five weeks, will contain five Sundays.
        if len(calendar_month) == 6 or (len(calendar_month) == 5 and calendar_month[0][0] == 1):
            
            print('Yay!')
            five_sunday_months.append(calendar.month_abbr[month])

    return five_sunday_months

print (find_five_sunday_months(2020))