from urllib.parse import urljoin
from bs4 import BeautifulSoup
from tornado import gen, httpclient, ioloop, queues
base_url = "http://www.tornadoweb.org/en/stable/"
concurrency = 20 #并发数
async def get_links(url):
http_client = httpclient.AsyncHTTPClient()
response = await http_client.fetch(url)
html = response.body.decode("utf8")
soup = BeautifulSoup(html)
links = [urljoin(base_url, a.get("href")) for a in soup.find_all("a",href=True)]
return links
async def main():
seen_set = set()
q = queues.Queue()
async def fetch_url(current_url):
if current_url in seen_set:
return
print("获取 {}".format(current_url))
seen_set.add(current_url)
next_urls = await get_links(current_url)
for new_url in next_urls:
if new_url.startswith(base_url):
await q.put(new_url)
async def worker():
async for url in q:
if url is None:
return
try:
await fetch_url(url)
except Exception as e:
print(e)
print("exec")
finally:
q.task_done()
await q.put(base_url)
workers = gen.multi([worker() for _ in range(concurrency)])
await q.join()
for _ in range(concurrency):
await q.put(None)
await workers
if __name__ == '__main__':
loop = ioloop.IOLoop.current()
loop.run_sync(main)
