冒泡排序：python编程入门，请大家帮我看一下非常感谢

Question

想问一下大神我这个代码运行报错，显示n没有定义，len(numbers)不是已经赋值给n了吗
代码：
def bubblesort(numbers):
n = len(numbers)
for i in range(n):
for j in range(0,n-i-1):
if numbers[j]>numbers[j+1]:
numbers[j],numbers[j+1]=numbers[j+1],numbers[j]
numbers = [64, 34, 25, 12, 22, 11, 90]
bubblesort(numbers)
print('排序后:')
for i in range(len(numbers)):
print('%d'%numbers[i],end='')

Answer 1

for循环缩进有问题，应该是跟n = len(numbers)同层级，否则就会出现n未定义。
代码修改如下：

def bubblesort(numbers):
    n = len(numbers)
    for i in range(n):
        for j in range(0,n-i-1):
            if numbers[j]>numbers[j+1]:
                numbers[j],numbers[j+1]=numbers[j+1],numbers[j]
numbers = [64, 34, 25, 12, 22, 11, 90]
bubblesort(numbers)
print('排序后:')
for i in range(len(numbers)):
    print('%d'%numbers[i],end=' ')