Lists inside dictionary and how to look for particular value

[mick verdu]

z={ 'PC2': ['02:02:02:02:02:02', '192.168.0.2', '200'],
    'PC3': ['03:03:03:03:03:03', '192.168.0.3', '200'],
    'PC1': ['01:01:01:01:01:01', '192.168.0.1', '200'] }

My solution:

z=raw_input("Enter Host, Mac, ip and time")
t=z.split()
t[0]=z[1:]
for key in dic:
    if t[2] in dic[key]:
        del dic[t[0]]
    else:
        dic[t[0]] = t[1:]


What I really want to achieve is:


How to search for a particular value inside list. First, I want the user to input hostname and ip. e.g. PC1 and 192.168.0.1, then need to find out if 192.168.0.1 has already been assigned to some host in dictionary. In this case I would need to skip for search inside list of user input host.

Forexample, if user inputs PC1 and 192.168.0.1 i would like to skip searching in above PC1's values. So it should detect matching only with different hosts and skip its own name.

If i input PC4 and 192.168.0.1 then it should detect conflict with PC1. So PC4 would be deleted(As soon as user inputs new host it is saved in above database then if conflict with others deleted)