Python 3 Directed Weighted Graph to Single Relationship Vectors

Question

I'm new to python 3 and for further processing I currently have to transform a directed weighted graph (e.g. A->B weight 20, B -> A weight 10) stored as a matrix to single relationship statements like [A,B,20] (node, node, weight).

The matrix looks like this:

matrix     A     B     C
A          0    10     0
B         20     0     5
C         10     5     0

The result I want to get is the following:

[A, B, 10], [B, A, 20], [B, C, 5], [C, A, 10], [C, B, 5]

Is there a simple solution in python to this? Maybe with some libraries to help.

The data lies in a .csv and I would read them in to my program. All I can think of as a solution is to go through each row and write all these statements in some nasty nested while and for mess.

Thx, mx

Answer 1

Just create a loop for rows and another for columns:

 table = [[0  ,  10   ,  0],[20 ,    0  ,   5],[10  ,   5   ,  0]]

 r = []
 l = ['A','B','C']
 for i in range(len(['A','B','C'])):
     for j in range(len(['A','B','C'])):
         if i!=j:
             r.append([l[i],l[j],table[i][j]])
 print(r)

, the result is this:

 [['A', 'B', 10], ['A', 'C', 0], ['B', 'A', 20], ['B', 'C', 5], ['C', 'A', 10], ['C', 'B', 5]]