Python爬虫之urllib库里面的处理错误

import urllib.request
# 这是一个不存在的页面，爬出这个页面的时候，就会出错，我们要做的就是捕捉这个错误
url = 'http://blog.youkuaiyun.com/u013630017/article/details/519211445'
headers = {
     'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36'
    }
#正常的请求
request = urllib.request.Request(url=url,headers=headers)
# response = urllib.request.urlopen(request)
#
# print(response.read().decode('utf-8'))
# 捕获异常的方法！！和 HTTPError 的错误
# 根据不同的错误，会进行精确捕捉
try:
    response = urllib.request.urlopen(request)
    print(response.read().decode('utf-8'))
except urllib.error.HTTPError as e:
    print(100)
    print(e.code)
    print(e.reason)
except urllib.error.URLError as e:
    print(200)
    print(e)
except Exception as e:
    print(300)
    print(e)
# print(response.read().decode('utf-8'))