循环删除列表中所有的3

list = [1,2,3,4,5,6,7,8,9,9,8,7,6,5,4,3,2,1,1,2,3,4,5,6,7,8,9]
print(list.count(3))

num = 0
all = list.count(3)
while num < all:
    list.remove(3)
    num += 1
print(list)