Python编程：简单网络爬虫的例子（用正则表达式匹配）

# 正则表达式, 按照一定规则提取字符串中的符合条件的内容
 str1='ghmjfdhngbrghmgjhngbfrthnhfgbfv'
 list1=re.findall('gj(.*?)fr',str1)   #返回值是列表
 print(list1)
 
 str2 = '''hellobtevrqtyjumuynthbg
 mybrtymuntbrgev
 juntybrwtvewbynutybworld'''
 list1 = re.findall('hello(.*?)world', str2, re.S)  # re.S允许跨行匹配
 print(list1)

爬取全书网小说

 import os
 import re
 import requests
 
 url = 'http://www.quannovel.com/read/620/'  # 需要进行爬虫的网址
 req = requests.post(url)  # 访问网页,获取网页内容
 book_name = re.findall('(.*?)(.*?)', req.text)  # 获取章节名
 
 url_list = re.findall('<a href="(.*?).html', req.text)  # 获取正文网址
 
 dict1 = {}
 for i in range(len(title_list)):
     dict1[title_list[i]] = f'{url}{url_list[i]}.html'  # 将目录和网址放到字典里
 
 if not os.path.exists(f'D:/{book_name}'):  # 如果没有以书名命名的目录,新建目录
     os.mkdir(f'D:/{book_name}')
 
 count = 1
 for k, v in dict1.items():
     if count > 5:
         break
     else:
         req = requests.get(v)  # 访问正文网页
         text = re.findall('class="page-content ">(.*?)<div class', req.text, re.S)[0]  # 获取文章内容
         text = text.replace('', '').replace('', '')
         with open(f'd:/{book_name}/{k}.txt','w+') as file1:
             file1.write(text)
     print(f'第{count}章爬取完毕')
     count += 1