从栅格中删除对角线

我正在尝试用python创建一个高度为5、宽度为10的图形。到目前为止,我有一段代码,它构造了一个图形,该图形具有对角线的边以及图形中的上、左、右和下边:

def construct_graph(data):
# initialize all of the astar nodes
nodes = [[ANode(x, y) for y in range(data['height'])] for x in range(data['width'])]
graph = {}
# make a graph with child nodes
for x, y in product(range(data['width']), range(data['height'])):
    node = nodes[x][y]
    graph[node] = []
    for i, j in product([-1, 0, 1], [-1, 0, 1]):
        if not (0 <= x + i < data['width']): continue
        if not (0 <= y + j < data['height']): continue
        if [x+i,y+j] in data['obstacle']: continue
        graph[nodes[x][y]].append(nodes[x+i][y+j])
return graph, nodes

如何修改上述函数以仅创建上、左、右和下链接?

注意:ANode只是一个普通的python类,它存储 x, y 对于节点。