What is the expected enhancement?

It would be great to have the ability to filter a graph's nodes and edges by some abstract criteria conditioned on a node's data payload.

A analogous feature seen in igraph would be the methods/functions of select and find.

# G is some arbitrary igraph.Graph

G.vs.select(lambda v: v["weight"] > 4)  # vertex selection
G.vs.find(name="foo")