<span style="font-size:18px;">import re
import urllib.request
import urllib
from collections import deque
queue = deque()
visited = set()
url = 'http://www.baidu.com' 
queue.append(url)
cnt = 0
while queue:
  url = queue.popleft()  # 隊首元素出隊
  visited |= {url}  # 標記為已訪問
  print('已經抓取: ' , cnt, '個連結','   正在抓取  ：  ' + url)
  cnt += 1
  urlop = urllib.request.urlopen(url)
  if 'html' not in urlop.getheader('Content-Type'):#抓取到的並沒有html格式的資料，則重新開始迴圈
    continue

  # 避免程式異常中止, 用try..catch處理異常
  try:
    data = urlop.read().decode('utf-8')
  except:
    continue

  linkre = re.compile('href=\"(.+?)\"')
  for x in linkre.findall(data):
    if 'http' in x and x not in visited:
      queue.append(x)
      print('把 ' + x +'加入佇列')</span>