Igraph and usage of Read(kclass, f, format=...) question

[ish]

I am using igraph package via Python interface. I have a list of edges of a graph one edge per line of input in a file (e.txt) and want igraph to read the edges into the graph. Can any one give me a usage hint of igraph.Graph.Read()??

import igraph
g = igraph.Graph()
g.add_vertices(3)    # 4 vertices
g.Read("e.txt", "egdes")

but does not work!

Any pointer will be appreciated.
-ish