冒泡排序

直接上代码 

a = [1,2,5,4,6,7,390]
def maopao(a):
    for i in range(0,len(a)-1):
        for j in range(0,len(a)-1-i):
            if a[j]>a[j+1]:
                a[j],a[j+1] = a[j+1],a[j]
    print(a)
    return a

maopao(a)