使用 Python 和 BeautifulSoup 启动网页抓取 - 分步教程中的错误

Question

按照 这个关于 使用 Python 和 BeautifulSoup 进行网页抓取的教程来学习诀窍 - 但是 Pycharm 返回一个我不明白的错误

你好呀！

尝试了上面提到的教程 ，使用调整后的链接作为实际链接，教程已过期（我使用的新链接）但是，当我单击“运行”时，我收到几个错误尝试了 PyCharm 的类型提示但无济于事。

import requests
from bs4 import BeautifulSoup

r = requests.get('https://pyvideo.org/events/pycon-se-2018.html')

soup = BeautifulSoup(r.text, 'html.parser')
results = [a.attrs.get('href') for a in soup.select('h4.entry-title a[href^=/pycon]')]

print(results)

预期是链接列表。我得到的是一堆错误

Traceback (most recent call last):
  File "/Users/maxschmitt/PycharmProjects/tester2/tester.py", line 7, in <module>
    results = [a.attrs.get('href') for a in soup.select('h4.entry-title a[href^=/pycon]')]
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/bs4/element.py", line 1376, in select
    return soupsieve.select(selector, self, namespaces, limit, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/soupsieve/__init__.py", line 114, in select
    return compile(select, namespaces, flags, **kwargs).select(tag, limit)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/soupsieve/__init__.py", line 63, in compile
    return cp._cached_css_compile(pattern, namespaces, custom, flags)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/soupsieve/css_parser.py", line 209, in _cached_css_compile
    CSSParser(pattern, custom=custom_selectors, flags=flags).process_selectors(),
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/soupsieve/css_parser.py", line 1048, in process_selectors
    return self.parse_selectors(self.selector_iter(self.pattern), index, flags)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/soupsieve/css_parser.py", line 882, in parse_selectors
    key, m = next(iselector)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/soupsieve/css_parser.py", line 1035, in selector_iter
    raise SelectorSyntaxError(msg, self.pattern, index)
soupsieve.util.SelectorSyntaxError: Malformed attribute selector at position 16
  line 1:
h4.entry-title a[href^=/pycon]

你知道我做错了什么吗？任何帮助，将不胜感激！

非常感谢！

Answer 1

您需要用/pycon“”换行或用\转义它

import requests
from bs4 import BeautifulSoup

r = requests.get('https://pyvideo.org/events/pycon-se-2018.html')

soup = BeautifulSoup(r.text, 'html.parser')
results = [a.attrs.get('href') for a in soup.select('h4.entry-title a[href^="/pycon"]')]

print(results)

或者

results = [a.attrs.get('href') for a in soup.select('h4.entry-title a[href^=\/pycon]')]