Printing the number of days in a given month and year [Python]

Question

I've been trying to work out a way to accomplish what's in the title, without using any imported calendar/datetime libs from Python. There's little function at the top for checking whether or not the year is a leap year, which I want to be able to reference when printing the number of days in a given February, however I'm not too sure how to do so. (I've guessed with something like output. bla bla)

So far I've come up with something like this, which should make clear what I want to do, but I'm still a bit new to Python, so I would love a few tips/help on fixing up my code for the task.

# A function to determine if a year is a leap year.
# Do not change this function.
def is_leap_year (year):
    return (year % 4 == 0) and (year % 100 != 0) or (year % 400 == 0)

# You should complete the definition of this function:

 def days_in_month(month, year):

    if month == 'September' or month == 'April' or month == 'June' or month == 'November'
    print 30

    elseif month == 'January' or month == 'March' or month == 'May' or month== 'July' or month == 'August' or month == 'October'\
    or month== 'December'
     print 31

    elseif month == 'February' and output.is_leap_year = True
    print 29

    elseif month == 'February' and output.is_leap_year = False
    print 28

    else print 'Blank'

Ok I've fixed up my code, and it seems to output the correct data for every month but February:

# A function to determine if a year is a leap year.
# Do not change this function.
def is_leap_year (year):
    return (year % 4 == 0) and (year % 100 != 0) or (year % 400 == 0)

# You should complete the definition of this function:

def days_in_month(month, year):

    if month in ['September', 'April', 'June', 'November']:
        print 30

    elif month in ['January', 'March', 'May', 'July', 'August','October','December']:
        print 31        

    elif month == 'February' and is_leap_year == True:
        print 29

    elif month == 'February' and is_leap_year == False:
        print 28

Any hints to fix up outputting for February?

EDIT: Just needed to add the argument year when referencing the first function. Here is the 100% working code for future reference:

# A function to determine if a year is a leap year.
# Do not change this function.
def is_leap_year(year):
    return (year % 4 == 0) and (year % 100 != 0) or (year % 400 == 0)

# You should complete the definition of this function:

def days_in_month(month, year):

    if month in ['September', 'April', 'June', 'November']:
        print 30

    elif month in ['January', 'March', 'May', 'July', 'August','October','December']:
        print 31        

    elif month == 'February' and is_leap_year(year) == True:
        print 29

    elif month == 'February' and is_leap_year(year) == False:
        print 28

    else:
        return None

​

​

​

Answer 1

Some syntax error in your code:

1. There should be no space before def days_in_month(month,year). Python use indentation to separate code blocks. This is the error you given in comment.
2. There is no elseif in python, it should be elif
3. output.is_leap_year = True, it should be is_leap_year(year) == True. The False part should be changed too.

4. after if statement and else there should be a :, like

   if month == 'September' or month == 'April' or month == 'June' or month == 'November':
       print 30
   elif month == 'January' or month == 'March' or month == 'May' or month== 'July' or month == 'August' or month == 'October' or month== 'December':
       print 31
   elif month == 'February' and is_leap_year(year) == True:
       print 29
   elif month == 'February' and is_leap_year(year) == False:
       print 28
   else:
       print 'Blank'
   

Answer 2

A more pythonic approach would be to define the mapping in a dictionary, then simply retrieve the values from the dictionary.

Try it out:

days_in_month_dict = {"January": 31, "February": 28, 
                      "March": 31, "April": 30,
                      "May": 31, "June": 30, 
                      "July": 31, "August": 31,
                      "September": 30, "October": 31,
                      "November": 30, "December": 31}

def is_leap_year(year):
    return (year % 4 == 0) and (year % 100 != 0) or (year % 400 == 0)

def days_in_month(year, month):
    if is_leap_year(year) and month == "February":
        return 28

    try: 
        #attempt to get value from dictionary 
        return days_in_month_dict[month]
    except KeyError:
        #key does not exist, so we caught the error
        return None

Answer 3

"""
Takes the year and month as input and returns the no. of days
"""
def is_leap_year (year):
    return (year % 4 == 0) and (year % 100 != 0) or (year % 400 == 0)

def days_in_month(month, year):
    if month == 'September' or month == 'April' or month == 'June' or month == 'November':
        result=30
    elif month == 'January' or month == 'March' or month == 'May' or month== 'July' or month == 'August' or month == 'October'or month== 'December':
        result=31

    elif month == 'February' and output.is_leap_year ==True:
        result=29

    elif month == 'February' and output.is_leap_year == False:
        result=28
    return result

print(is_leap_year(2016))
print(days_in_month('September',2016))

Answer 4

month = int (input ('month (1-12): '))

if month < 13:
    if month == 2:
        year = int (input ('year: '))
        if year % 4 == 0:
            if year % 100 == 0:
                if year % 400 == 0:
                    print ('29')
                else:
                    print ('28')
            else:
                print ('29')
        else:
            print ('28')

    elif month >= 8:
        if month % 2 == 0:
            print ('31')
        else:
            print ('30')

    elif month % 2 == 0:
        print ('30')
    else:
        print ('31')

else:
    print ('Only 1-12 accepted')

Answer 5

month=input("month")
year=int(input("year"))
if year%4==0:
        year=('leap year')
if month in ['September', 'April', 'June', 'November']:
        print ("30")

elif month in ['January', 'March', 'May', 'July', 'August','October','December']:
        print ("31")        

elif month == 'February' and year == "leap year":
        print ("29")

elif month == 'February' and  year != "leap year":
        print ("28")

else:
    print("none")