Maze generator to Python New Bing

Maze generator to Python New Bin.mdg

# Import random module for shuffling and sampling
import random

# Define a function that returns a spanning tree from a graph using loop-erased random walk
def spanning_tree(vertices, adjacency_list):
  # Initialize an empty list for the spanning tree
  spanning_tree = []
  # Initialize a list of visited vertices with 0 values
  visited = [0] * vertices
  # Create a list of nodes from 0 to vertices - 1
  nodes = list(range(vertices))
  # Shuffle the nodes randomly
  random.shuffle(nodes)
  # Mark the first node as visited with value 1
  visited[nodes[0]] = 1
  # Loop through the remaining nodes
  for i in range(1, vertices):
    # If the node is already visited, skip it
    if visited[nodes[i]]:
      continue
    # Otherwise, perform loop-erased random walk from the node and update the spanning tree and visited list
    spanning_tree, visited = lerw(nodes[i], i + 1, adjacency_list, spanning_tree, visited)
  
  # Return the spanning tree as output
  return spanning_tree

# Define a helper function that performs loop-erased random walk from a given vertex and returns an updated spanning tree and visited list 
def lerw(vertex, round, adjacency_list, spanning_tree, visited):
  
   # Initialize an empty list for storing current path 
   current = []
   # Loop until vertex is not visited 
   while not visited[vertex]:
     # Mark vertex as visited with round value 
     visited[vertex] = round 
     # Append vertex to current path 
     current.append(vertex) 
     # Choose next vertex randomly from adjacency list excluding negative values 
     next_vertex = random.choice([v for v,_ in adjacency_list[vertex] if v >=0]) 

     if visited[next_vertex] == round: 
       # Erase loop by popping vertices from current path until next_vertex is reached and marking them as unvisited 
       while vertex != next_vertex: 
         vertex = current.pop() 
         visited[vertex] = False 

     # Update vertex with next_vertex 
     vertex = next_vertex 

   # Append final vertex to current path  
   current.append(vertex) 

   # Extend spanning tree with pairs of adjacent vertices in current path  
   for i in range(len(current) -1):  
     spanning_tree.append((current[i],current[i+1])) 

   return (spanning_tree ,visited)