在for循环中使用递归时，如何找到最短路径距离？

# 定义全局变量保存最短路径距离
shortest_distance = float('inf')

def find_shortest_path(current_node, target_node, current_distance):
    global shortest_distance

    # 判断是否达到目标节点
    if current_node == target_node:
        # 更新最短路径距离
        shortest_distance = min(shortest_distance, current_distance)
        return

    # 遍历所有可能的路径
    for next_node in current_node.neighbors:
        # 计算从当前节点到下一节点的距离
        distance = calculate_distance(current_node, next_node)

        # 如果当前路径距离已经大于等于最短路径距离，则提前终止递归
        if current_distance + distance >= shortest_distance:
            continue

        # 递归调用，继续搜索下一节点
        find_shortest_path(next_node, target_node, current_distance + distance)

# 示例调用
start_node = graph.get_start_node()
end_node = graph.get_end_node()
find_shortest_path(start_node, end_node, 0)