python 测试常见面试题

1、统计元素的个数：

a = [1, 2, 3, 1, 1, 2]

dict = {}

for key in a:

dict[key] = dict.get(key,0) + 1

print(dict)

def  count(m):

for  i  in  a:

result = a.count(m)

print(result)

if  __name__ == "__main__":

count(1)

2、冒泡排序

def  bubble_sort(num):

for i in  range(len(num)-1):   #这个循环负责设置冒泡排序进行的次数,即循环的趟数

for  j in  range(len(num)-1-i):   #i的初始值为0，每次循环确定一个值，循环一次，减少一趟

if  num[j] > num[j+1]:

num[j],num[j+1] = num[j+1],num[j]

return  num

if  __name__ == "__main__":

num = [1,2,3,4,9,5,2,3,8]

print(bubble_sort(num))