Python: Eigenvalue of Specific Number

Question

I have a laplacian matrix that I already derived myself. I want my corresponding eigenvalue to equal zero. So my equation is (laplacian matrix) * (eigenvectors) = 0

I want to find ALL the eigenvectors that make the above equation true. So essentially I'm looking for all the eigenvectors that when multiplied against laplacian matrix equals 0.

Below is the code I tried:

laparray = np.array([[3, -3, 0, 0], [-3, 3, 0, 0], [0, 0, 3, -3], [0, 0, -3, 3]])

zeroarray = np.array([0, 0, 0, 0])

np.linalg.solve(laparray, zeroarray)

I get the following error:

What is wrong with my code and how can I solve for all the eigenvectors?