从网格中删除对角线

Question

我正在尝试在python中创建高度5和宽度10的图。到目前为止，我有这段代码，它构造了一个图形，该图形具有对角线的边缘以及图形中的向上，左侧，右侧和向下边缘：

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

如何修改上述功能以仅创建向上，向左，向右和向下的链接？

注意：ANode只是一个普通的python类，它存储节点的x, y。

Answer 1

不要将product用于内部循环，只需指定所需的邻居：

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 [(-1, 0), (0, -1), (0, 1), (1, 0)]:
        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