判断对象相等时的问题(==)

 

snake.velocity = Point(0,-1)
print(snake.velocity)
print(Point(0,-1))
print(snake.velocity == Point(0,-1))    #FALSE,因为Point(0,-1)每次都是一个新地址
aaa = Point(0,-1)
snake.velocity = aaa
print(snake.velocity == Point(0,-1))    #FALSE,因为Point(0,-1)每次都是一个新地址
print(snake.velocity == aaa)          #TRUE,因为aaa固定了地址,snake.velocity指向的刚好是aaa指向的地址

 

posted @ 2019-04-09 12:47  林丶  阅读(297)  评论(0编辑  收藏  举报