Добавить и удалить заданное ребро матрицы неориентированного графа

import random
import pprint
import copy
 
 
def graph_generator(n, mean_degree, max_weight):
    if mean_degree < 2 * (n - 1) / n:
        mean_degree = 2 * (n - 1) / n
    if mean_degree > n - 1:
        mean_degree = (n - 1)
    num_of_edges = int(mean_degree * n / 2)
 
    W = []
    for i in range(n):
        W.append(['-'] * n)
        W[i][i] = 0
 
    stack = []
    for i in range(n):
        stack.append(i)
    random.shuffle(stack)
    while stack:
        first = stack.pop()
        if stack:
            second = random.choice(stack)
            W[first][second] = W[second][first] = random.randint(1, max_weight)
 
    edges_not_tree = num_of_edges - (n - 1)
    for _ in range(edges_not_tree):
        first = random.randint(0, n - 1)
        second = random.randint(0, n - 1)
    W[first][second] = W[second][first] = random.randint(1, max_weight)
 
    return W
 
 
W = graph_generator(6, 1, 9)
pprint.pprint(W)
 
 
def convert_to_adj(W):
    D = copy.deepcopy(W)
    for i in range(len(D)):
        for j in range(len(D)):
            if D[i][j] == '-':
                D[i][j] = 0
            elif D[i][j] > 0:
                D[i][j] = 1
    return D
 
 
##A = convert_to_adj(W)
print("##########################")
 
 
# pprint.pprint(A)
 
 
def remove_edge(W, u, v):
    D = copy.deepcopy(W)
    for u in range(u, v):
        for v in range(u, v):
            D[u][v] = '-'
            D[v][u] = '-'
    return D
 
 
def add_edge(W, u, v, e):
    D = copy.deepcopy(W)
    for u in range(u, v):
        for v in range(u, v):
            D[u][v] = e
            D[v][u] = e
    return D
 
B = remove_edge(W, 4, 5)
pprint.pprint(B)
print("#####################")
C = add_edge(W, 4,5,6)
pprint.pprint(C)