to print just the first part of the 3d numpy array as a 2d grid, you can index into the first 2d array using M[0].

M = np.array([[[3,3,3], [3,3,3], [3,3,3]], [[4,4,4], [4,4,4], [4,4,4]]])

#print the first 2d part
for row in M[0]:
    print(' '.join(map(str, row)))

output:

3 3 3
3 3 3
3 3 3