python算法实现1——冒泡排序

# 冒泡排序 
def bubble_sort(arr): 
    arr_len = len(arr) 
    for i in range(arr_len-1): 
        for j in range(arr_len-1-i): 
            if arr[j] > arr[j+1]: 
                arr[j], arr[j+1] = arr[j+1], arr[j]


if __name__ == '__main__': 
    
    arr = [5,4,3,1,2]
    bubble_sort(arr) 
    print(arr)