[Python知识库]python 爬虫基础学习笔记

1.用 Python 登录网页

from urllib.request import urlopen

# if has Chinese, apply decode()
html = urlopen(
    "https://mofanpy.com/static/scraping/basic-structure.html"
).read().decode('utf-8')
print(html)

2.匹配网页内容
** 2.1正则表达式**

##正则表达式
import re  
res = re.findall(r"<title>(.+?)</title>", html)
print("\nPage title is: ", res[0])
##因为这个段落在 HTML 中还夹杂着 tab, new line, 所以我们给一个 flags=re.DOTALL 来对这些 tab, new line 不敏感.
res = re.findall(r"<p>(.*?)</p>", html, flags=re.DOTALL)    # re.DOTALL if multi line
print("\nPage paragraph is: ", res[0])