一：列表排序

    1. li = [34,32,67,23,12,7,4,1]
    2. print(len(li))
    3. #冒泡排序：
    4. for i in range(0,len(li)):
    5.     for n in range(0,len(li)-i-1):
    6.         # print(len(li)-i-1)
    7.         if li[n] > li[n+1]:         #冒泡排序
    8.             li[n],li[n+1] = li[n+1],li[n]
    9.         else:
    10.             continue
    11.     print(li)
    12. print(li)


    方法二:

    1. li = [34,32,67,23,12,7,4,1]
    2. print(len(li))
    3. for i in range(0,8):         #冒泡排序
    4.     for j in range(0,8-i-1):
    5.         if li[j] > li[j+1]:
    6.             li[j],li[j+1] = li[j+1],li[j]
    7.         # print(li)
    8.     print(li)
    9. print(li)


    选择排序：

    1. li = [34,32,67,23,12,7,4,1]
    2. N = []
    3. for i in range(0,len(li)):
    4.     N.append(max(li))
    5.     li.remove(max(li))
    6.     print(N)
    7. print(N)
    1. li = [34,32,67,23,12,7,4,1]
    2. for i in range(0,len(li)):
    3.     max_index = i            #假设最大的事max_index
    4.     for j in range(i,len(li)-1):
    5.         if li[max_index] < li[j]:        #34<34 34<32 34<67 67<23 .....
    6.             max_index = j
    7.     li[i],li[max_index] = li[max_index],li[i]      
    8. print(li)

    二：九九乘法表

    1. for row in range(1, 10):
    2.     for num in range(1, row + 1):
    3.         print(f'{num}*{row}={num * row} ', end='')
    4.     print()

    作业三： 判断完全数

    1. num = int(input('请输入：'))
    2. sum_num = 0
    3. for i in range(1,num):
    4.     if num % i == 0:        #判断余数是否为0
    5.         sum_num += 1
    6. if sum_num == num:          #和为sun_num
    7.     print(f'{num}是完全数')

    作业四 1234 组成不重复的三位数：

    1. sun_num = 0
    2. for i in range(1,5):
    3.     for j in range(1,5):
    4.         for k in range(1,5):
    5.             if i != j and i != k and j != k:
    6.                 print(i,j,k)