urllib库（7）异常

常出现的两种异常：

1、HTTPError：出现在url种某个字符出现问题的时候
2、URLError:出现在这个url不存在的时候
其中：HTTPError是URLError的一个子类

示例：

import urllib.request
import urllib.error
url1 = 'https://blog.csdn.net/boysoft2002/article/details/132520234'
url2 = 'https://blog.csdn.net/boy__soft2002/article/details/132520234'#HTTPError
url3 = 'http://www.yangkeyu.com'#URLError



headers = {
'Accept':
'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7',
'User-Agent':
'Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Mobile Safari/537.36 Edg/118.0.2088.46'
}


try:
    request = urllib.request.Request(url=url3, headers=headers)
    response = urllib.request.urlopen(request)
    content = response.read().decode('utf-8')
    print(content)
except urllib.error.HTTPError:
    print('出现http错误')
except urllib.error.URLError:
    print("出现了url错误")