问Python如何使用队列的广度优先来搜索矩阵？

from queue import Queue

maze=open(input())

matrix=maze.readlines()

matrix=[i.strip() for i in matrix]

matrix=[i.split() for i in matrix]

q=Queue()

row=0

column=0

q.put(row,column)

while not q.empty():

     x=q.get()

     if matrix[x[0]][x[1]+1]=="0" and x[1]+1<len(matrix[0]):

         q.put(x[0],x[1]+1)

         matrix[x[0]][x[1]+1]=="2"

    if matrix[x[0]+1][x[1]]=="0" and x[0]+1<len(matrix):

         q.put(x[0]+1,x[1])

         matrix[x[0]+1][x[1]]=="3"

    if matrix[x[0]][x[1]-1]=="0" and x[1]-1>len(matrix[0]):

         q.put(x[0],x[1]-1)

         matrix[x[0]][x[1]-1]=="4"

    if matrix[x[0]-1][x[1]]=="0" and x[0]-1<len(matrix):

         q.put(x[0]-1,x[1])

         matrix[x[0]-1][x[1]]=="5"