Calculate number of days between two dates using Python

Question

I have written below python code for calculating number of days between two dates. The code runs fine , however it failed in one of the scenario, for example: if my start date is on 01/01/2016 and end date is on 28/02/2016 (dd/mm/yyyy format), then expected out put should be 58 days. However, my code gives result of 56 days. Below is the code snippet :

##Variable Declaration####################
daysofMonths = [31,28,31,30,31,30,31,31,30,31,30,31]
FinalCount = 0
####### Step 1: Leap Year Function####################################
######################################################################
##if (year is not divisible by 4) then (it is a common year)
##else if (year is not divisible by 100) then (it is a leap year)
##else if (year is not divisible by 400) then (it is a common year)
##else (it is a leap year)
######################################################################

def LeapYear(year):
        if year % 4 == 0:
                if year % 100 == 0:
                        if year % 400 == 0:
                                return True
                        else:
                                return False
                else:
                        return True
        else:
                return False



####### Step 2: Get the number of days for months Function####################################

def DaysforMonths(month,year):
        x = 0
        c = 0
        for c in range(0,month,1):
                if c == 1:
                        if LeapYear(year)== True:
                                x = x+29
                        else:
                                x = x+28
                else:
                        x = x+ daysofMonths[c]
        return x



####### Step 3: Get the inputs from user ###################################        

year1 = int(input("Enter the year:"))
month1 = int(input("Enter the month:"))
day1 = int(input("Enter the day:"))
year2 = int(input("Enter the year:"))
month2 = int(input("Enter the month:"))
day2 = int(input("Enter the day:"))

####### Step 3.1: Get number of days between years function ###################################
def TotalDaysBetweenYear(year1,year2):
        i = year1
        countdays=0
        if year1 == year2:
                return countdays
        else:
                for i in range (year1,year2,1):

                        if (LeapYear(i)== True):
                                countdays = countdays+366
                        else:
                                countdays = countdays+365

        return countdays

####### Step 4: Get the number of days between two dates Function####################################
def daysBetweenDates(year1, month1, day1, year2, month2, day2):
        FinalCount = TotalDaysBetweenYear(year1,year2) - DaysforMonths(month1,year1)
        FinalCount = FinalCount - day1
        FinalCount = FinalCount + DaysforMonths(month2,year2)
        FinalCount = FinalCount + day2
        return FinalCount
print ("Number of days between two date is:",daysBetweenDates(year1, month1, day1, year2, month2, day2))

Answer 1

Below is the final code and it works for all the scenario. The intention was not to use datetime function, since I am learning Python and new to programming :)

##Variable Declaration####################
daysofMonths = [31,28,31,30,31,30,31,31,30,31,30,31]
FinalCount = 0
####### Step 1: Leap Year Function####################################
######################################################################
##if (year is not divisible by 4) then (it is a common year)
##else if (year is not divisible by 100) then (it is a leap year)
##else if (year is not divisible by 400) then (it is a common year)
##else (it is a leap year)
######################################################################

def LeapYear(year):
        if year % 4 == 0:
                if year % 100 == 0:
                        if year % 400 == 0:
                                return True
                        else:
                                return False
                else:
                        return True
        else:
                return False



####### Step 2: Get the number of days for months Function####################################

def DaysforMonths(month,year):
        x = 0
        c = 0
        for c in range(0,month,1):
                if c == 1:
                        if LeapYear(year)== True:
                                x = x+29
                        else:
                                x = x+28
                else:
                        x = x+ daysofMonths[c]
        return x



####### Step 3: Get the inputs from user ###################################        

year1 = int(input("Enter the year:"))
month1 = int(input("Enter the month:"))
day1 = int(input("Enter the day:"))
year2 = int(input("Enter the year:"))
month2 = int(input("Enter the month:"))
day2 = int(input("Enter the day:"))

####### Step 3.1: Get number of days between years function ###################################
def TotalDaysBetweenYear(year1,year2):
        i = year1
        countdays=0
        if year1 == year2:
                return countdays
        else:
                for i in range (year1,year2,1):

                        if (LeapYear(i)== True):
                                countdays = countdays+366
                        else:
                                countdays = countdays+365

        return countdays

####### Step 4: Get the number of days between two dates Function####################################
def daysBetweenDates(year1, month1, day1, year2, month2, day2):
        if year1 == year2:
                n = 0
                j = 0
                remDaysofEndMonth = 0
##              Get the Total number of days between start month and last before end month  
                for j in range(month1-1,month2,1): 
                        if j == 1:
                                if LeapYear(year1):
                                        n = n+29
                                else:
                                        n=n+28
                        else:
                                n=n+daysofMonths[j]
                if month2-1 == 1:
                        if LeapYear(year1):
                                remDaysofEndMonth = 29 - (29-day2)
                        else:
                                remDaysofEndMonth = 28 - (28-day2)
                else:
                        remDaysofEndMonth = daysofMonths[month2-1] - (daysofMonths[month2-1]-day2)

                FinalCount = n + remDaysofEndMonth - day1
                return FinalCount
        else:
                FinalCount = TotalDaysBetweenYear(year1,year2) - DaysforMonths(month1,year1)
                FinalCount = FinalCount - day1
                FinalCount = FinalCount + DaysforMonths(month2,year2)
                FinalCount = FinalCount + day2
                return FinalCount

print ("Number of days between two date is:",daysBetweenDates(year1, month1, day1, year2, month2, day2))

Answer 2

Your DaysforMonths will calculate current month as it already over.

For example: DaysForMonth(01, 2016) will return 31, but should return 0. Jenuary is not over yet.

You should not count current month.

Also (if possible) please follow pep8 when using python.

Answer 3

Why on earth are you reimplementing the wheel and not just using datetime?

>>> import datetime
>>> start = datetime.date(2016,1,1)
>>> end = datetime.date(2016,2,28)
>>> end-start
datetime.timedelta(58)
>>> delta = end-start
>>> delta.days
58