#小练习 冒泡排序

alist=['deff', 'ABC','xtazz','Abc','abc',]

#len(alist)=5

for i in range(len(alist)-1): # i = 0 1 2 3

    for j in  range(len(alist)-i-1):

        if alist[j] > alist[j+1]:

            alist[j],alist[j+1] =alist[j+1],alist[j]

print alist

 趟数      该趟比较次数

 1                len -1

 2                len -2

 3                len -3

 ..                 ....

 n-1              1