Python爬虫包BeautifulSoup异常处理（二）_Python

Python爬虫包BeautifulSoup异常处理（二）

2021-03-06 00:02SuPhoebe Python

这篇文章主要为大家详细介绍了Python爬虫包BeautifulSoup的异常处理，具有一定的参考价值，感兴趣的朋友可以参考一下

面对网络不稳定，页面更新等问题，很可能出现程序异常的问题，所以我们要对程序进行一些异常处理。大家可能觉得处理异常是一个比较麻烦的活，但在面对复杂网页和任务的时候，无疑成为一个很好的代码习惯。

网页‘404'、‘500'等问题

									try:

									    html = urlopen('http://www.pmcaff.com/2221')

									  except HTTPError as e:

									    print(e)

返回的是空网页

				?

									if html is None:

									    print('没有找到网页')

目标标签在网页中缺失

				?

									try:

									    #不存在的标签

									    content = bsObj.nonExistingTag.anotherTag 

									  except AttributeError as e:

									    print('没有找到你想要的标签')

									  else:

									    if content == None:

									      print('没有找到你想要的标签')

									    else:

									      print(content)

实例

									if sys.version_info[0] == 2:

									  from urllib2 import urlopen # Python 2

									  from urllib2 import HTTPError

									else:

									  from urllib.request import urlopen # Python3

									  from urllib.error import HTTPError

									from bs4 import BeautifulSoup

									import sys

									def getTitle(url):

									  try:

									    html = urlopen(url)

									  except HTTPError as e:

									    print(e)

									    return None

									  try:

									    bsObj = BeautifulSoup(html.read())

									    title = bsObj.body.h1

									  except AttributeError as e:

									    return None

									  return title

									title = getTitle("http://www.pythonscraping.com/exercises/exercise1.html")

									if title == None:

									  print("Title could not be found")

									else:

									  print(title)