如何将节点关系node_relations改为用户输入模式，有用户输入节点关系，使其达到用户可以通过该界面输入关系，显示关系图，并运行后给出尽可能多的拓扑排序结果的效果

from collections import defaultdict
from graphviz import Digraph


def create_graph(node_relations):
    graph = defaultdict(list)
    for u, v in node_relations:
        graph[u].append(v)
    return graph


def topological_sort(graph):
    visited = {}
    for key, values in graph.items():
        visited[key] = False
        for val in values:
            visited[val] = False
    stack = []

    def topological_sort_util(v):
        visited[v] = True
        for node in graph[v]:
            if not visited[node]:
                topological_sort_util(node)
        stack.insert(0, v)

    for node in visited.keys():
        if not visited[node]:
            topological_sort_util(node)

    return stack


def draw_graph(node_relations):
    dot = Digraph(comment='node graph', filename='blueprintNodeGraph-neato', format='png', engine='neato')
    dot.attr(
        'node',
        shape='box', style='rounded,filled',
        fixedsize='false',
        fontname='Microsoft YaHei', fontsize='12')
    node_size = 0
    for relation in node_relations:
        node_size += 1
        dot.edge(relation[0], relation[1], len='3')
        print(f"{relation[0]} -> {relation[1]}")
    dot.render(directory='doctest-output', view=True).replace('\\', '/')


if __name__ == '__main__':
    # 节点关系
    node_relations = (('MA140', 'MA141'),('MA141', 'MA140'),('MA141', 'CS225'),
                      ('MA141', 'CS150'),('CS150', 'MA141'),('CS150', 'CS155'),
                      ('CS225', 'MA141'),('CS225', 'CS155'),('CS225', 'CS300'),
                      ('CS225', 'CS250'),('CS225', 'CS230'),('CS155', 'CS225'),
                      ('CS155', 'CS200'),('CS155', 'CS150'),('CS200', 'CS155'),
                      ('CS250', 'CS350'),('CS250', 'CS360'),('CS250', 'CS225'),
                      ('CS350', 'CS250'),('CS230', 'CS225'),('CS300', 'CS340'),
                      ('CS300', 'CS301'),('CS300', 'CS225'),('CS301', 'CS300'),
                      ('CS340', 'CS360'),('CS340', 'CS300'),('CS340', 'CS345'),
                      ('CS345', 'CS340'),('CS360', 'CS390'),('CS360', 'CS250'),
                      ('CS360', 'CS340'),('CS390', 'CS360'))
    # 创建图
    graph = create_graph(node_relations)
    # 拓扑排序
    topo_list = topological_sort(graph)
    print(topo_list)
    # 绘图
    draw_graph(node_relations)

【以下回答由 GPT 生成】

from collections import defaultdict
from graphviz import Digraph

def create_graph(node_relations):
    graph = defaultdict(list)
    for u, v in node_relations:
        graph[u].append(v)
    return graph

def topological_sort(graph):
    visited = {}
    for key, values in graph.items():
        visited[key] = False
        for val in values:
            visited[val] = False
    stack = []

    def topological_sort_util(v):
        visited[v] = True
        for node in graph[v]:
            if not visited[node]:
                topological_sort_util(node)
        stack.insert(0, v)

    for node in visited.keys():
        if not visited[node]:
            topological_sort_util(node)

    return stack

def draw_graph(node_relations):
    dot = Digraph(comment='node graph', filename='blueprintNodeGraph-neato', format='png', engine='neato')
    dot.attr('node', shape='box', style='rounded,filled', fixedsize='false', fontname='Microsoft YaHei', fontsize='12')
    node_size = 0
    for relation in node_relations:
        node_size += 1
        dot.edge(relation[0], relation[1], len='3')
    dot.render(directory='doctest-output', view=True).replace('\\', '/')

if __name__ == '__main__':
    # 通过用户界面输入节点关系
    node_relations_input = input("请输入节点关系，以逗号分隔：")
    node_relations = [tuple(relation.split(',')) for relation in node_relations_input.split()]

    # 创建关系图
    graph = create_graph(node_relations)

    # 进行拓扑排序
    sorted_nodes = topological_sort(graph)

    # 输出拓扑排序结果
    print("拓扑排序结果:")
    for node in sorted_nodes:
        print(node)

    # 绘制关系图并显示在界面上
    draw_graph(node_relations)

通过上述代码的修改，用户可以通过界面输入节点关系，并且能够显示关系图并进行拓扑排序。代码使用了input函数获取用户输入的节点关系，并通过逗号分隔后转换为节点关系列表。然后调用了create_graph函数创建关系图，并使用topological_sort函数进行拓扑排序。最后，通过draw_graph函数绘制关系图并显示在界面上。