python面试题

1、三元运算符

//简单的if else语句，可以使用三元运算符来表示，如
if 1==1:
    name = "wangkc"
else :
    name = "alex"

//三元表达式如下：
name = wangkc if 1=1 else "alex"

2、lambda表达式：

　　可以接收任意多个参数并且返回单个表达式值的函数。lambda函数不能包含命令，他们所包含的表达式不能超过一个

//定义lambda表达式
my_lambda = lambda arg:arg+1
result = my_lambda(3)

 3、sorted函数结合lambda

1、dict = {"name":"wkc","age":18,"city":"神州"}
    list = sorted(dict.items(),key =lambda i:i[0],reverse=False)
//得到一个元祖列表，list =[("age",18),("city","神州"]
    new_dict = {}
    for i in list:
        new_dict[i[0]=i[1[]]
    print(new_dict)

2、li=[("a,1),("b",2),("c",3)]
    sorted(li,key=lambda x:x[0],reverse=False)

4、socket编程服务端和客户端

#coding:utf-8

import socket
if __name__ == '__main__':
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind(('localhost', 8001))
    sock.listen(5)

    while True:
        connection,address = sock.accept()
        try:
            connection.settimeout(5)
            buf = connection.recv(1024)
            if buf == '1':
                connection.send('welcome to server!')
            else:
                connection.send('please go out!')
        except socket.timeout:
            print 'time out'

        connection.close()

#coding:utf-8

import socket
import time

if __name__ == '__main__':
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect(('localhost', 8001))
    time.sleep(2)
    sock.send('1')
    print sock.recv(1024)
    sock.close()

5、全局解释器锁（global interpreter lock）