Networkx - Shortest path length

Question

I'm using networkx to manage large network graph which consists of 50k nodes.

I want to calculate the shortest path length between a specific set of nodes, say N.
For that i'm using the nx.shortest_path_length function.

In some of the nodes from N there might not be a path so networkx is raising and stopping my program.

Is there any way to run this program without any error?
And to tell to shortest_path_length to return some maximum value?

Code simply uses nx.shortest_path_length(G,i,j)in loop. and error is as follows

raise nx.NetworkXNoPath("No path between %s and %s." % (source, target)) networkx.exception.NetworkXNoPath: No path between V and J

Answer 1

import networkx as nx
G=nx.Graph()
G.add_nodes_from([1,2,3,4])
G.add_edge(1,2)
G.add_edge(3,4)
try:
    n=nx.shortest_path_length(G,1,4)
    print n
except nx.NetworkXNoPath:
    print 'No path'