# Graph with python: how to set up a graph correctly?

I want to use graph reduction algorithm on images in my project, I am using **python 2.7** .

I found a pymaxflow implementation , but the documentation doesn't seem that clear. I will give an example, here is my 5 * 5 matrix:

```
>>> A
array([[ 0, 1, 2, 3, 4],
[ 5, 6, 7, 8, 9],
[10, 11, 12, 13, 14],
[15, 16, 17, 18, 19],
[20, 21, 22, 23, 24]])
```

The virtual terminal nodes, **S** (source) and **T** (sink), must be associated with infinite weights across all pixels of the left and right columns of the matrix, respectively.This is what I would like to get:

Here is my code to get this but it doesn't work

`left_most = concatenate((np.zeros((1, A.shape[0])), np.arange(A.shape[0]).reshape(1, A.shape[0]))).astype(np.uint64) left_most = np.ravel_multi_index(left_most, A.shape) right_most = concatenate((np.ones((1, A.shape[0])) * size(A, 1) - 1, np.arange(A.shape[0]).reshape(1, A.shape[0]))).astype(np.uint64) right_most = np.ravel_multi_index(right_most, A.shape) g.add_grid_tedges(left_most, np.ones(left_most.shape) * np.inf, np.zeros(left_most.shape)) g.add_grid_tedges(right_most, np.zeros(right_most.shape), np.ones(right_most.shape) * np.inf)`

`g.maxflow()`

makes the python console an endless loop. I'm not sure about my implementation: what is the way to generate the correct graph that can be used in the graph shortening algorithm?

Thank!

Ps If you know a solution with a different library will let me know, any suggestion would be really appreciated.

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