convert an adjacency list to edge list format

adjacency-list-to-edges.py

import sys
"""
usage:
    python adjacency-list-to-edges.py [adjacency-list-file] [edge-list-file]
example:
    this program will help convert this:
        [adjacency-list-file]
        flower,fruit
        carafe,flower,glass,window
        flower,dew
    into this:
        [edge-list-file]
        flower,fruit
        carafe,flower
        carafe,glass
        carafe,window
        flower,glass
        flower,window
        glass,window
        flower,dew
"""

adjacency_list_filename = sys.argv[1]
edge_list_filename = sys.argv[2]

edge_list = []
with open(adjacency_list_filename, 'r') as f:
    for line in f:
        line = line.rstrip('\n').split(',')
        while len(line) > 0:
            source = line[0]
            for target in line[1:]:
                edge_list.append("%s,%s" % (source, target))
            line.pop(0)

with open(edge_list_filename, 'w') as f:
    f.write('%s\n' % ('\n'.join(edge_list)))