如何在python中同时执行两个循环？

Question

I have two lists:

 host_list = ["10.3.11.250", "10.3.24.45", "10.5.3.5","10.3.4.5"]
 ip_value = ["34.45.34.5", "10.3.11.250","10.3.4.5"]

I want to check whether the data of host_list is present in ip_value or not if it is then append the ip_value to another list. I am doing in this way check the following code:

for host,ip in zip(host_list ,ip_value):
    if host_list == ip_value
        list_ip = list_ip.append(ip)

But it does nothing.Why? and what should list_ip returns it will returns: {"10.3.11.250", "10.3.4.5"}

Answer 1

These are sets , not lists. You can calculate a difference of them:

list_ip = host_list - ip_value

returns

{'10.5.3.5', '10.3.24.45'}

Edited : ok, now they are two lists. Change the code to:

list_ip = list(set(host_list) - set(ip_value))

returns

['10.5.3.5', '10.3.24.45']

Answer 2

使用set

another_list = list(set(host_list) - set(ip_value))

Answer 3

To answer the question, why does the code you give do nothing:

for host,ip in zip(host_list ,ip_value): 
    if host_list == ip_value 
        list_ip = list_ip.append(ip)

You are comparing host_list to ip_value, and not comparing host to ip. host_list != ip_value, thus the next statement is never executed.