Python实现冒泡，插入，选择排序

#python插入排序    def insertSort(a):        for i in range(len(a)-1):            #print a,i              for j in range(i+1,len(a)):                if a[i]>a[j]:                    temp = a[i]                    a[i] = a[j]                    a[j] = temp        return a            #Python的冒泡排序       def bubbleSort(alist):        for passnum in range(len(alist)-1,0,-1):            #print alist,passnum            for i in range(passnum):                if alist[i]>alist[i+1]:                    temp = alist[i]                    alist[i] = alist[i+1]                    alist[i+1] = temp        return alist            #Python的选择排序     def selectionSort(alist):        for i in range(len(alist)-1,0,-1):            maxone = 0            for j in range(1,i+1):                if alist[j]>alist[maxone]:                    maxone = j            temp = alist[i]             alist[i] = alist[maxone]            alist[maxone] = temp         return alist            alist = [54,26,93,17,77,31,44,55,20]    #print bubbleSort(alist)    alist = [54,26,93,17,77,31,44,55,20]    print selectionSort(alist)