Python爬虫之正则表达式（3）

 # re.sub
 # 替换字符串中每一个匹配的子串后返回替换后的字符串
 import re
 content = 'Extra strings Hello 1234567 World_This is a Regex Demo Extra strings'
 content = re.sub('\d+', '', content)
 print(content)
 
 import re
 content = 'Extra strings Hello 1234567 World_This is a Regex Demo Extra strings'
 content = re.sub('\d+', 'Replacement', content)
 print(content)
 
 # \1 是转义字符
 import re
 content = 'Extra strings Hello 1234567 World_This is a Regex Demo Extra strings'
 content = re.sub('(\d+)', r'\1 8910', content)
 print(content)
 
 # re.compile
 # 将正则字符串编译成正则表达式对象
 # 将一个正则表达式串编译成正则对象，以便于复用该匹配模式
 import re
 content = '''Hello 1234567 World_This
 is a Regex Demo'''
 pattern = re.compile('Hello.*Demo', re.S)
 result = re.match(pattern, content)
 print(result)

下面是爬取豆瓣图书的实战代码

 import requests
 import re
 content = requests.get('https://book.douban.com/').text
 # print(content)
 pattern = re.compile('<li.*?cover.*?title="(.*?)".*?author">(.*?)</div>.*?year">(.*?)</span>.*?</li>', re.S)
 results = re.findall(pattern, content)
 for result in results:
     name, author, date = result
     author = re.sub("\s", "", author)
     date = re.sub("\s", "", date)
     print("【书名】：", name, " 【作者】：", author, " 【出版年】：", date)

本篇内容为：崔庆才爬虫学习笔记