Python——关于爬虫基础Urllib实战

今天来实际运行一下关于爬虫的一些小玩意

首先，我们打开IDLE，今天我们查询一下关于CSDN的标题名称。

>>> import urllib
>>> import urllib.request
>>> data=urllib.request.urlopen("https://www.csdn.net").read().decode("utf-8","ignore")
>>> len(data)
385957
>>> import re
>>> pat="<title>(.*?)</title>"
>>> re.compile(pat,re.S).findall(data)
['CSDN-专业IT技术社区']


#爬到硬盘的文件中

>>> urllib.request.urlretrieve("http://www.jd.com",filename="本地路径(且要保存的文件名字") 
>>> urllib.request.urlretrieve("https://www.csdn.net",filename="E:\\IDLE文件\\csdn.html")



#浏览器伪装

>>> opener=urllib.request.build_opener()
>>> UA=("user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.100 Safari/537.36")
>>> opener.addheaders=[UA]
>>> urllib.request.install_opener(opener)
>>> data=urllib.request.urlopen("https://www.csdn.net").read().decode("utf-8","ignore")
Traceback (most recent call last):
  File "<pyshell#9>", line 1, in <module>
    data=urllib.request.urlopen("https://www.csdn.net").read().decode("utf-8","ignore")
  File "D:\python\lib\urllib\request.py", line 222, in urlopen
    return opener.open(url, data, timeout)
  File "D:\python\lib\urllib\request.py", line 523, in open
    req = meth(req)
  File "D:\python\lib\urllib\request.py", line 1268, in do_request_
    for name, value in self.parent.addheaders:
ValueError: too many values to unpack (expected 2)

上面当浏览器伪装时，为什么会错误呢，是要解包的值太多