怎样给python输入的数据设置条件呀

大佬们，想问这个问题:

try:
    n,x,y=input().split()
    if int(y)<=int(n)*int(x):
        raise ValueError("输入值不符合要求")
except ValueError as e:
    print("引发异常：",repr(e))

使用条件判断，不满足时抛出异常。还可以使用断言：

>>> n, x, y = 3, 5, 7 # 满足条件，下面的断言不会抛出异常
>>> assert isinstance(n,int) and isinstance(x,int) and isinstance(y,int) and y<=n*x, '期望参数n,x,y是整数，且y不大于n和x的乘积'
>>> n, x, y = 3.0, 5, 7 # 浮点数，不满足条件，抛出异常
>>> assert isinstance(n,int) and isinstance(x,int) and isinstance(y,int) and y<=n*x, '期望参数n,x,y是整数，且y不大于n和x的乘积'
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    assert isinstance(n,int) and isinstance(x,int) and isinstance(y,int) and y<=n*x, '期望参数n,x,y是整数，且y不大于n和x的乘积'
AssertionError: 期望参数n,x,y是整数，且y不大于n和x的乘积
>>> n, x, y = 3, 5, 17 # y大于n和x的乘积，不满足条件，抛出异常
>>> assert isinstance(n,int) and isinstance(x,int) and isinstance(y,int) and y<=n*x, '期望参数n,x,y是整数，且y不大于n和x的乘积'
Traceback (most recent call last):
  File "<pyshell#7>", line 1, in <module>
    assert isinstance(n,int) and isinstance(x,int) and isinstance(y,int) and y<=n*x, '期望参数n,x,y是整数，且y不大于n和x的乘积'
AssertionError: 期望参数n,x,y是整数，且y不大于n和x的乘积
>>>