Python 链接爬虫

import re
import urllib.request

def getlink(url):
    headers = ('User-Agent','Mozilla/5.0 (Windows NT 10.0; WOW64; rv:57.0) Gecko/20100101 Firefox/57.0')
    opener = urllib.request.build_opener()
    opener.addheaders = [headers]

    urllib.request.install_opener(opener)
    file = urllib.request.urlopen(url)
    data=str(file.read())
    pat = '(https?://[^\s)";]+\.(\w|/)*)'
    link = re.compile(pat).findall(data)
    link=list(set(link))
    return link

url = 'http://blog.csdn.net/'
linklist = getlink(url)
for link in linklist:
    print(link[0])