这么写:
x=int(input('请输入一个四位数的数字:'))
a=x%10
b=int(x/10%10)
c=int(x/100%10)
d=int(x/1000)
if c>d and b>c and a>b and a==b+c+d:
print(str(x)+'是幸运数字!')
n = input("输入一个四位数的数字:")
a = int(n[0])
b = int(n[1])
c = int(n[2])
d = int(n[3])
if b>a and c>b and d>c and a+b+c==d:
print(n,"是幸运数字")
else:
print(n,"不是幸运数字")