基于边权重的2个节点之间的所有路径

Question

I am new to programming and I am trying to find all possible paths between 2 nodes in which the sum of weight of edges is less than a given value. I have implemented my graph in NetworkX and the nodes have no weight whatsoever. Is there any predefined function in NetworkX I can use, or I need to write my own algorithm for same and if I do, what will be the best approach for same?

Edit: The code right now is just reading input values and adding edges along with their respective weight through add_edge method defined in NetworkX. I am also trying to understand the code for all_simple_paths_graph method defined in NetworkX in order to modify it to keep a tab of weight but so far little headway, being new to Python.

Answer 1

Found an easy implementation for this by modifying an existing function of NetworkX. This function prints all paths between given nodes along which the sum of weight of edges is not more than given value.

def all_paths(G, source, target, w):
    cutoff = len(G)-1
    visited = [source]
    stack = [iter(G[source])]
    weight = 0
    while stack:
        children = stack[-1]
        child = next(children, None)
        if child is None:
            stack.pop()
            visited.pop()
        elif len(visited) < cutoff:
            if child == target:
                if (visited[-1],child) in G.nodes():
                    temp = G[visited[-1]][child]['weight']
                else:
                    temp = G[child][visited[-1]]['weight']
                if weight+temp <= w:
                    yield visited + [target]
            elif child not in visited:
                if (visited[-1],child) in G.nodes():
                    weight += G[visited[-1]][child]['weight']
                else:
                    weight += G[child][visited[-1]]['weight']
                visited.append(child)
                stack.append(iter(G[child]))
        else: 
            if child == target or target in children:
                if (visited[-1],child) in G.nodes():
                    temp = G[visited[-1]][child]['weight']
                else:
                    temp = G[child][visited[-1]]['weight']
                if weight+temp <= w:
                    yield visited + [target]
            stack.pop()
            visited.pop()