冒泡排序：
def bubble_sort(li): #冒泡排序
for i in range(len(li)-1):
for j in range(len(li)-i-1):
if li[j] > li[j+1]:
li[j],li[j+1] = li[j+1],li[j]选择排序：
def select_sort(li): #选择排序
for i in range(len(li)-1):
min_loc = i
for j in range (i+1,len(li)):
if li[j] < li[min_loc]:
min_loc = j
li[i],li[min_loc] = li[min_loc],li[i]插入排序：
def insert_sort(li): #插入排序
for i in range(1,len(li)):
tmp = li[i]
j = i - 1
while j >= 0 and li[j] > tmp:
li[j+1] = li[j]
j = j - 1
li[j+1] = tmp
