Load graph from csv

graph-tool
1

Hi,

I'm loading directed weighted graph from csv file into graph-tool graph
graph. The organization of the input csv file is:

1,2,300
2,4,432
3,89,1.24
...

Where the fist two entries of a line identify source and target of an edge
and the third number is the weight of the edge.

Currently I'm using:

import csv
g = gt.Graph()
e_weight = g.new_edge_property("float")
f_network = open(in_file_directory+ '/'+network_input, 'r')
reader_network = csv.reader(f_network, delimiter=delimiter)
for edge in reader_network:
     e = g.add_edge(int(edge[0]), int(edge[1]))
     e_weight[e] = float(edge[2])
f_network.close()

However it takes quite long to load the data (I have network of 10 millions
of nodes). I have tried to make it faster by using g.add_edge_list, but this
works only for unweighted graphs. Any suggestion how to make it faster?

2

Yes, use g.add_edge_list() for the edges, and put the weights separately
via the array interface for property maps:

    e_weight.a = weight_list

The weight list should have the same ordering as the edges you passed to
g.add_edge_list().

Best,
Tiago