python实现冒泡排序、插入排序

def bubble_sort(S):
    N=len(S)
    for i in range(N-1):        #epoch次数
        for j in range(N-1-i):
            if S[j]>S[j+1]:
                S[j],S[j+1]=S[j+1],S[j]
    return(S)
S=[2,3,5,4,1]
bubble_sort(S)

def insertion_sort(S):
    N=len(S)
    for i in range(N-1):
        for j in range(i+1):
            if S[i+1]<S[j]:
                S[j],S[j+1:i+2]=S[i+1],S[j:i+1]
    return(S)
insertion_sort(S)