def get_neighbor_distances(net, v):
    """Create a lookup of neighbors with distances for dijkstra.

    Parameters
    ----------
    net : tigernet.Network
    v  : int
        Source node for iteration of neighbors.

    Returns
    -------
    neighbors : dict
        Lookup dictionary in the form ``{neighor_ID: neighbor_distance}``.
    """

    neighbors = {}

    for e in net.node2segm[v]:

        if net.segm2node[e][0] != v:
            neighbors[net.segm2node[e][0]] = net.segm2len[e]

        else:
            neighbors[net.segm2node[e][1]] = net.segm2len[e]

    return neighbors