广度优化搜索python实现

from collections import deque
graph={}
graph['you']=["alice", "bob", "claire"]
graph["bob"] = ["anuj", "peggy"]
graph["alice"] = ["peggy"]
graph["claire"] = ["thom", "jonny"]
graph["anuj"] = []
graph["peggy"] = []
graph["thom"] = []
graph["jonny"] = []
def search_seller(name):
    search_queue = deque()
    search_queue += graph[name]
    check=[]
    while search_queue:
      person=search_queue.popleft()
      if person not in check:
          if is_seller(person):
              print(person+' is a seller')
          else:
              check.append(person)
              search_queue+=graph[person]     #理解队列的工作原理
def is_seller(person):
    if 'm' in person:
        return True

search_seller('you')