我正在尝试学习Python 3.x,以便能够爬取网站。人们建议我使用Beautiful Soup 4或lxml.html。有人可以指点我使用Python 3.x的BeautifulSoup教程或示例吗?
谢谢您的帮助。
我正在尝试学习Python 3.x,以便能够爬取网站。人们建议我使用Beautiful Soup 4或lxml.html。有人可以指点我使用Python 3.x的BeautifulSoup教程或示例吗?
谢谢您的帮助。
我实际上刚刚写了一份完整的网络爬虫指南,其中包括Python中的一些示例代码。我在Python 2.7上编写和测试了它,但是我使用的两个软件包(requests和BeautifulSoup)根据Wall of Shame是完全兼容Python 3的。
这里是一些Python网络爬虫的起步代码:
import sys
import requests
from BeautifulSoup import BeautifulSoup
def scrape_google(keyword):
# dynamically build the URL that we'll be making a request to
url = "http://www.google.com/search?q={term}".format(
term=keyword.strip().replace(" ", "+"),
)
# spoof some headers so the request appears to be coming from a browser, not a bot
headers = {
"user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_5)",
"accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
"accept-charset": "ISO-8859-1,utf-8;q=0.7,*;q=0.3",
"accept-encoding": "gzip,deflate,sdch",
"accept-language": "en-US,en;q=0.8",
}
# make the request to the search url, passing in the the spoofed headers.
r = requests.get(url, headers=headers) # assign the response to a variable r
# check the status code of the response to make sure the request went well
if r.status_code != 200:
print("request denied")
return
else:
print("scraping " + url)
# convert the plaintext HTML markup into a DOM-like structure that we can search
soup = BeautifulSoup(r.text)
# each result is an <li> element with class="g" this is our wrapper
results = soup.findAll("li", "g")
# iterate over each of the result wrapper elements
for result in results:
# the main link is an <h3> element with class="r"
result_anchor = result.find("h3", "r").find("a")
# print out each link in the results
print(result_anchor.contents)
if __name__ == "__main__":
# you can pass in a keyword to search for when you run the script
# be default, we'll search for the "web scraping" keyword
try:
keyword = sys.argv[1]
except IndexError:
keyword = "web scraping"
scrape_google(keyword)
如果您只是想更多地了解Python 3并且已经熟悉Python 2.x,则可能会对这篇文章有所帮助,它介绍了从Python 2转换到Python 3的内容。