方法1:

year = int(input("請輸入年:"))
mouth = int(input("請輸入月:"))
day = int(input("請輸入日:"))
mouth_day = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
if year % 400 == 0 or (year % 100 != 0 and year % 4 == 0):
    mouth_day[1] = 29
print(sum(mouth_day[:mouth-1])+day)

方法2:

from datetime import datetime
new_day = datetime(2017
 
, 12, 31, 12, 36, 45)
start_day = datetime(2017, 1, 1)

print(new_day - start_day)

輸出的結果天數人為地再加1,還可以輸出幾時幾刻