不是很好的方法（Python）

YMD=[0,31,28,31,30,31,30,31,31,30,31,30,31]
def runnian(Y1):
   if Y1%100==0:
       return 1
   else:
       if Y1%4==0 and Y1%100!=0:
           return 1
       else:
           return 0
def dijitian(M,D):
   sum1=0
   for i in range(M):
       sum1=sum1+YMD[i]
   return sum1+D
while 1:
   s=input()
   if len(s)==0:
       break
   Y, M, D = s.split('/')
   Y = int(Y)
   M = int(M)
   D = int(D)
   zt=runnian(Y)
   djt=dijitian(M,D)
   if zt and M>2:
       djt=djt+1
   print(djt)