This is input_file text:

1 2,1 8,2 2 1,1 3,1 3 2,1 4,1 4 3,1 5,1 5 4,1 6,1 6 5,1 7,1 7 6,1 8,1 8 7,1 1,2 

I would like to open the input file and read in the contents. I want to read the data into a Python dictionary where each key was a vertex identifier and each value was a list of edges.

This is my expectation output:

{ 1: [(2, 1), (8, 2)], 2: [(1, 1), (3, 1)], 3: [(2, 1), (4, 1)], 4: [(3, 1), (5, 1)], 5: [(4, 1), (6, 1)], 6: [(5, 1), (7, 1)], 7: [(6, 1), (8, 1)], 8: [(7, 1), (1, 2)] }