from html.parser import HTMLParser
import urllib.request
with urllib.request.urlopen('https://www.python.org/events/python-events/') as url:
content = url.read()
html = content.decode('utf-8')
class MyHtmlParser(HTMLParser):
def __init__(self):
HTMLParser.__init__(self)
self.location = []
self.flag = False
def handle_starttag(self, tag, attrs):
if tag == 'span' and 'event-location' in dict(attrs)['class']:
self.flag = True
def handle_data(self, data):
if self.flag:
self.location.append(data)
self.flag = False
parser = MyHtmlParser()
parser.feed(html)
for i in parser.location:
print(i)运行结果：
Traceback (most recent call last): File "C:/Users/user/PycharmProjects/untitled1/python6.py", line 22, in <module> parser.feed(html) File "C:\Users\user\AppData\Local\Programs\Python\Python35-32\lib\html\parser.py", line 111, in feed self.goahead(0) File "C:\Users\user\AppData\Local\Programs\Python\Python35-32\lib\html\parser.py", line 171, in goahead k = self.parse_starttag(i) File "C:\Users\user\AppData\Local\Programs\Python\Python35-32\lib\html\parser.py", line 345, in parse_starttag self.handle_starttag(tag, attrs) File "C:/Users/user/PycharmProjects/untitled1/python6.py", line 14, in handle_starttag if tag == 'span' and 'event-location' in dict(attrs)['class']: KeyError: 'class'
为什么会有KeyError呢？这是爬取的目标网站的一段代码：
<span class="event-location">Capital One McLean Conference Center in McLean, VA, USA</span>
没有大小写错误，怎么会有KeyError呢？
另外我爬取这一段代码：
<a href="/events/python-events/461/">PyConES 2016 - Almeria</a>
把代码改成if tag == 'a' and 'python-event' in dict(attrs)['href']:
就可以成功爬取。。。
所以是什么问题呢？
是class有禁忌？？？？
如果某个span没有 class属性，dict就报错~
改成这样：