Number of Days Alive | Python Fiddle

def ifLeapYear(year):
    if year % 400 == 0:
        return True
    elif year % 100 == 0:
        return False
    elif year % 4 == 0:
        return True
    else:
        return False
def daysThisYear(month, day):
    days_per_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    dayCount = 0
    i = 0
    while i < month - 1:
        dayCount += days_per_month[i]
        i += 1
    return dayCount + day
def daysLastYear(month, day):
    days_per_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    dayCount = 0
    i = 11
    if month == 12:
        return 32 - day
    while i + 1 > month:
        dayCount += days_per_month[i]
        i -= 1
    return dayCount + (days_per_month[month - 1] - day)

def daysBetweenDates(year1, month1, day1, year2, month2, day2):
    ##
    leap_year_count = 0
    i = year1 + 1   
    while i < year2:
        if ifLeapYear(i):
            leap_year_count += 1
            i += 1
        else:
            i += 1
    if ifLeapYear(year2) and month2 > 2:
        leap_year_count += 1
    if ifLeapYear(year1) and month1 < 3:
        leap_year_count += 1
    #print leap_year_count
    if year1 == year2:
        if ifLeapYear(year1) and month1 < 3 and month2 > 2:
        	day_count = daysThisYear(month2, day2) - daysThisYear(month1, day1) + 1
        	return day_count
        else:
            day_count = daysThisYear(month2, day2) - daysThisYear(month1, day1)
            return day_count
    if year1 + 1 == year2:
        day_count = daysThisYear(month2, day2) + daysLastYear(month1, day1) + leap_year_count
        return day_count
    day_count = daysThisYear(month2, day2) + daysLastYear(month1, day1)
    day_count += leap_year_count + (year2-year1-1)*365
    return day_count
    
#print daysBetweenDates(2012,1,1,2012,2,28)    
#print daysBetweenDates(2012,1,1,2012,3,1)
#print daysBetweenDates(2011,6,30,2012,6,30)
#print daysBetweenDates(2011,1,1,2012,8,8)
#print daysBetweenDates(1900,1,1,1999,12,31)

### Alternate::
"""
def daysInMonth(m):
    if m == 4 or m == 6 or m == 9 or m == 11:
        return 30
    if m == 2:
        return 28
    return 31
def isLeapYear(y):
    if y % 400 == 0:
        return True
    elif y % 100 == 0:
        return False
    elif y % 4 == 0:
        return True
    else:
        return False
def nextDay(year, month, day):
    if isLeapYear(year):
        if month == 2 and day == 29:
            return year, 3, 1
    if day == daysInMonth(month):
        if month == 12:
            return year+1, 1, 1
        if month == 2 and isLeapYear(year):
            return year, month, day+1
        return year, month+1, 1
    return year, month, day+1
def dateIsAfter(year1, month1, day1, year2, month2, day2):
    if year1 > year2:
        return True
    if year1 == year2:
        if month1 > month2:
            return True
        if month1 == month2:
            return day1 > day2
    return False

def daysBetweenDates(year1, month1, day1, year2, month2, day2):
    #  Returns the number of days between year1/month1/day1
    #  and year2/month2/day2. Assumes inputs are valid dates
    #  in Gregorian calendar.
    # program defensively! Add an assertion if the input is not valid!
    assert dateIsAfter(year2, month2, day2, year1, month1, day1)
    days = 0
    while dateIsAfter(year2, month2, day2, year1, month1, day1):
        days += 1
        (year1, month1, day1) = nextDay(year1, month1, day1)
    return days
"""

# Test routine

def test():
    test_cases = [((2012,1,1,2012,2,28), 58), 
                  ((2012,1,1,2012,3,1), 60),
                  ((2011,6,30,2012,6,30), 366),
                  ((2011,1,1,2012,8,8), 585 ),
                  ((1900,1,1,1999,12,31), 36523)]
    for (args, answer) in test_cases:
        result = daysBetweenDates(*args)
        if result != answer:
            print "Test with data:", args, "failed"
        else:
            print "Test case passed!"

test()

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