title: Listing adjacent cells
body: <p>I have a 570 x 800 matrix with id values. What I would like to do if find the adjacent neighbors for each item. The max number of neighbors would be 8 unless the cell is along a boundary. In that case, there would be three neighbors. I want to append the neighbors to a list. I saw the posting for finding neighbors when each cell has x and y coordinates which was very helpful, but how would modify the code with no coordinates. The ids come in as a string which is fine because I use it as a key in a dictionary. Any help would be appreciated. </p>