我自己的方法：
def leap_year(y): #判断是否是闰年
if (y % 4 == 0 and y % 100 != 0) or y % 400 == 0:
return True
else:
return False
def days_in_month(y, m): #判断每个月都有几天
if m in [1, 3, 5, 7, 8, 10, 12]:
return 31
elif m in [4, 6, 9, 11]:
return 30
else:
if leap_year(y):
return 29
else:
return 28
def days_this_year(year): #判断今年共几天
if leap_year(year):
return 366
else:
return 365
def days_passed(year, month, day): #判断今年过了几天
m = 1
days = 0
while m < month:
days += days_in_month(year, m)
m += 1
return days + day
def daysBetweenDates(year1, month1, day1, year2, month2, day2):
if year1 == year2:
return days_passed(year2, month2, day2) - days_passed(year1, month1, day1)
else:
sum1 = 0
y1 = year1
while y1 < year2:
sum1 += days_this_year(y1)
y1 += 1
return sum1-days_passed(year1,month1,day1)+days_passed(year2,month2,day2)
def leap_year(y): 
