Python: 创建表示网络拓扑的拓扑类

创建表示网络拓扑的拓扑类。

创建类的实例时，描述拓扑的字典将作为参数传递。字典可能包含“重复”连接。“重复”连接是指字典中有两个连接的情况：

("R1", "Eth0/0"): ("SW1", "Eth0/1")
("SW1", "Eth0/1"): ("R1", "Eth0/0")
任务是在最终字典中只留下其中一个链接，无论哪个链接。

在每个实例中，必须创建一个拓扑实例变量，其中包含拓扑字典，但已经没有“重复项”。拓扑实例变量应在创建实例后立即包含没有“重复项”的字典。

from rich import print
from pprint import pprint

class Topology:
    def __init__(self, topology_dict):
        self.topology = self._normalize(topology_dict)

    def _normalize(self, topology_dict):
        # 消重方法 #1：
        return {
            min(local, remote): max(local, remote)
            for local, remote in topology_dict.items()
        }

        # 消重方法 #2：
        # topo = {}
        # for local, remote in topology_dict.items():
        #     if not topo.get(remote) == local:
        #         topo[local] = remote
        # return topo

        # 消重方法 #3：
        # normalized_topology = {}
        # for box, neighbor in topology_dict.items():
        #     if not neighbor in normalized_topology:
        #         normalized_topology[box] =neighbor
        # return normalized_topology

    def delete_link(self, from_port, to_port):
        if self.topology.get(from_port) == to_port:
            del self.topology[from_port]
        elif self.topology.get(to_port) == from_port:
            del self.topology[to_port]
        else:
            print('There is no such link')

    def delete_node(self, node):
        original_size = len(self.topology)
        for src, dest in list(self.topology.items()):
            if node in src or node in dest:
                del self.topology[src]
        if original_size == len(self.topology):
            print("There is no such device")

    def add_link(self, src, dest):
        keys_and_values = self.topology.keys() | self.topology.values()
        if self.topology.get(src) == dest:
            print("Such a connection already exists.")
        elif src in keys_and_values or dest in keys_and_values:
            print("A link to one of the port exists")
        else:
            self.topology[src] = dest


# 1、初始化拓扑图
topology_example = {
    ("R1", "Eth0/0"): ("SW1", "Eth0/1"),
    ("R2", "Eth0/0"): ("SW1", "Eth0/2"),
    ("R2", "Eth0/1"): ("SW2", "Eth0/11"),
    ("R3", "Eth0/0"): ("SW1", "Eth0/3"),
    ("R3", "Eth0/1"): ("R4", "Eth0/0"),
    ("R3", "Eth0/2"): ("R5", "Eth0/0"),
    ("SW1", "Eth0/1"): ("R1", "Eth0/0"),
    ("SW1", "Eth0/2"): ("R2", "Eth0/0"),
    ("SW1", "Eth0/3"): ("R3", "Eth0/0"),
}

# 2、创建拓扑图，删除冗余部分
print('2、创建拓扑图，删除冗余部分'.center(80, '#'))
top = Topology(topology_example)
print(top.topology)

# 3、删除链接
print('3、删除链接'.center(80, '#'))
top.delete_link(("R3", "Eth0/1"), ("R4", "Eth0/0"))
pprint(top.topology)
top.delete_link(('R5', 'Eth0/0'), ('R3', 'Eth0/2'))
pprint(top.topology)
top.delete_link(('R5', 'Eth0/0'), ('R3', 'Eth0/2'))

# 4、删除节点设备
print('4、删除节点设备'.center(80, '#'))
top = Topology(topology_example)
top.delete_node('SW1')
print(top.topology)
top.delete_node('SW1')

# 5、添加连接
print('5、添加连接'.center(80, '#'))
top = Topology(topology_example)
top.add_link(('R1', 'Eth0/4'), ('R7', 'Eth0/0'))
print(top.topology)
top.add_link(('R1', 'Eth0/4'), ('R7', 'Eth0/0'))
top.add_link(('R1', 'Eth0/4'), ('R7', 'Eth0/5'))

输出：

#################################2、创建拓扑图，删除冗余部分#################################
{
    ('R1', 'Eth0/0'): ('SW1', 'Eth0/1'),
    ('R2', 'Eth0/0'): ('SW1', 'Eth0/2'),
    ('R2', 'Eth0/1'): ('SW2', 'Eth0/11'),
    ('R3', 'Eth0/0'): ('SW1', 'Eth0/3'),
    ('R3', 'Eth0/1'): ('R4', 'Eth0/0'),
    ('R3', 'Eth0/2'): ('R5', 'Eth0/0')
}
#####################################3、删除链接#####################################
{('R1', 'Eth0/0'): ('SW1', 'Eth0/1'),
 ('R2', 'Eth0/0'): ('SW1', 'Eth0/2'),
 ('R2', 'Eth0/1'): ('SW2', 'Eth0/11'),
 ('R3', 'Eth0/0'): ('SW1', 'Eth0/3'),
 ('R3', 'Eth0/2'): ('R5', 'Eth0/0')}
{('R1', 'Eth0/0'): ('SW1', 'Eth0/1'),
 ('R2', 'Eth0/0'): ('SW1', 'Eth0/2'),
 ('R2', 'Eth0/1'): ('SW2', 'Eth0/11'),
 ('R3', 'Eth0/0'): ('SW1', 'Eth0/3')}
There is no such link
####################################4、删除节点设备####################################
{('R2', 'Eth0/1'): ('SW2', 'Eth0/11'), ('R3', 'Eth0/1'): ('R4', 'Eth0/0'), ('R3', 'Eth0/2'): ('R5', 'Eth0/0')}
There is no such device
#####################################5、添加连接#####################################
{
    ('R1', 'Eth0/0'): ('SW1', 'Eth0/1'),
    ('R2', 'Eth0/0'): ('SW1', 'Eth0/2'),
    ('R2', 'Eth0/1'): ('SW2', 'Eth0/11'),
    ('R3', 'Eth0/0'): ('SW1', 'Eth0/3'),
    ('R3', 'Eth0/1'): ('R4', 'Eth0/0'),
    ('R3', 'Eth0/2'): ('R5', 'Eth0/0'),
    ('R1', 'Eth0/4'): ('R7', 'Eth0/0')
}
Such a connection already exists.
A link to one of the port exists