检查元素是否已经在列表中？

Question

I have a list of lists as follows:

aList= [['192.168.1.3', '0080.4522.ad08', '2013/05/02 19:10:10', 'automatic'],
['192.168.1.2', '0080.4522.ad08', '2013/05/02 19:05:00', 'automatic']]

When adding another list I want to check if the ip or mac address are in another list before adding them, if they are already in the list of lists I don't want to add them. For instance if I was testing 192.168.1.3 it would not add it to the list as that element exists somewhere already. So I may be trying to add this list again but I want it to fail:

['192.168.1.3', '0080.4522.ad08', '2013/05/02 19:10:10', 'automatic']

The way I have been doing it is looping through the lists and setting a boolean once the element is found, but I don't feel this way is great. How would you do it? I know that IP will always be element one of each list but relying on index also seems a bad way to do things.

Answer 1

You can use any :

>>> lis = ['192.168.1.3', '0080.4522.ad08', '2013/05/02 19:10:10', 'automatic']
if any(item[0] == lis[0] or item[1] == lis[1]  for item in aList)
    #then don't add
else:
    #add

Answer 2

A good way to solve this is to use objects, and make the list a list of objects instead of a list of list/tuples. You could then override the compare-function for objects and use the normal "in" statement.

class Client:
    def __init__(self,  ip, mac, timedate, mode):
        self.ip = ip
        self.mac = mac
        self.timedate = timedate
        self.mode = mode

    def __eq__(self, object):
        if type(object) != type(self):
            return False

        if object.ip == self.ip or object.mac == self.mac
            return True
        return False

you could then do something like

client = Client("127.0.0.1", "abwdds", date, mode)
if client not in list:
    doSomething()
    list.append(client)

Answer 3

如果IP地址是数据的关键列，则应使用字典将IP地址与其他列映射到元组（或列表）。

Answer 4

Use a dictionary to hold your connections.

cons = [{'IP':'192.168.1.3', 'MAC':'0080.4522.ad08', 'timestamp':'2013/05/02 19:10:10', 'type':'automatic'},
        {'IP':'192.168.1.2', 'MAC':'0080.4522.ad08', 'timestamp':'2013/05/02 19:05:00', 'type':'automatic'}]

def add_con(con):
    if any((con['IP'] == c['IP'] or con['MAC'] == c['MAC']) for c in con):
        # duplicate
    else:
        # new

You could easily wrap this functionality into a class.

---

class ConnectionManager():

    def __init__(self):
        self.connections = []

    def add_con(ip, mac, timestamp, mode):
        if any((ip == c['IP'] or mac == c['MAC']) for c in self.connections):
            # duplicate
            return False # possible option?
        else:
            self.connections.append({'IP':ip, 'MAC':mac, 'timestamp':timestamp, 'mode':mode})
            return True # possible option?