Question

I have two dictionary objects, connections and network. This can be visualized as a graph, where each node is a computer and connections depict an edge between the computers and node. Network is a dictionary objects of unique networks where the computers can be a part, for ex

1,2  
2,3  
4,5  
5,1 

are four connection information for nodes 1 through 1
connections would thus be {1->1,2->1,3->1,4->2,5->1}
and network {1->0,2->1}
which means
computer 1,2,3,5 are part of n/w 1
computer 4 is part of n/w 2
again n/w 2 is interconnected to n/w 1
I have to read a file with thousand of such connection information
while doing so, for each connection info read I have to perform a non-sequential loop as follows

while network.has_key(connections[node1]):
    connections[node1]=network[connections[node1]] 

Is there a better way to optimize the above loop? If required I can share my entire code for the purpose

Answer 1

while network.has_key(connections[node1]):
    connections[node1]=network[connections[node1]] 

That code does the lookup for network[connections[node1]] twice once for has_key and once for [].

It also repeatedly accesses connections[node1]

Instead you can do:

current = connections[node1]
while True:
    try:
         current = network[current]
    except KeyError:
         break
connections[node1] = current

But chances are better improvements can be had be reworking the rest of your code. But for that you may find http://codereview.stackexchange.com to be a better site.