自学教程：Python正则表达式的应用详解

import reusername = input('请输入用户名：')# 通过compile编译正则表达式创建Pattern对象username_pattern = re.compile(r'^/w{6,20}$')print(type(username_pattern))# 通过给Pattern对象发消息实现匹配检查matcher = username_pattern.match(username)print(type(matcher))if matcher is None:    print('无效的用户名')else:    print(matcher.group())

username = input('请输入用户名：')matcher = re.fullmatch(r'/w{6,20}', username)#^是开始符，$是结束符# matcher = re.match(r'^/w{6,20}$', username)if matcher is None:    print('用户名不合法！！！')else:    print(matcher)    print(matcher.group())

import recontent = """报警电话：110，我们班是Python-2105班，我的QQ是9597658，我的手机号是13811223344，谢谢！"""searcher = re.search(r'1[3-9]/d{9}', content)if not searcher:    print('没有找到手机号')else:    print(searcher.group())

import recontent = """报警电话：110，我们班是Python-2105班，我的QQ是9597658，我的手机号是13811223344，谢谢！"""pattern = re.compile(r'/d+')matcher = pattern.search(content)while matcher:    print(matcher.group())    # 从上一次匹配成功的结束位置开始搜索    matcher = pattern.search(content, matcher.end())

import recontent = """报警电话：110，我们班是Python-2105班，我的QQ是9597658，我的手机号是13811223344，谢谢！"""pattern = re.compile(r'/d+')results = pattern.findall(content)# 没有创建正则表达式对象时，也可以用这种方法# results = re.findall(r'/d+', content)for result in results:    print(result)

import reimport requestsresp = requests.get('https://www.sohu.com/')# .表示任意字符，+表示匹配一个或任意多个，？表示惰性匹配，尽可能短的匹配pattern = re.compile(r'href="http.+?"')# 拿到搜狐首页content = resp.textmatcher = pattern.search(content)while matcher:    print(matcher.group()[6:-1])    matcher = pattern.search(content, matcher.end())pattern2 = re.compile(r'title=".+?"')title_list = pattern2.findall(content)for title in title_list:    print(title[7:-1])

import reimport requestsresp = requests.get('https://www.sohu.com/')# 匹配整个a标签，但是只捕获()中的内容 ---> 正则表达式的捕获组# .*连在一起就意味着任意数量的不包含换行的字符pattern = re.compile(r'<a/s.*?href="(.+?)".*?title="(.+?)".*?>')content = resp.textresults = pattern.findall(content)for href, title in results:    print(title)    if not href.startswith('https://www.sohu.com'):        href = 'https://www.sohu.com' + href    print(href)

import recontent = '你真是一个沙雕煞笔，Fuck you!'# pattern = re.compile(r'[傻沙煞][逼笔雕鄙]|马化腾|fuck|shit', flags=re.IGNORECASE)# modified_content = pattern.sub('*', content)# print(modified_content)# |表示分支modified_content = re.sub(r'[傻沙煞][逼笔雕鄙]|fuck|shit', '*', content, flags=re.I)print(modified_content)

import repoem = '床前明月光，疑是地上霜，举头望明月，低头思故乡。'# sentences_list = re.split(r'[，。]', poem)# sentences_list = re.split(r'，|。', poem)pattern = re.compile(r'[，。]')sentences_list = pattern.split(poem)# sentences_list = [sentence for sentence in sentences_list if sentence]# print(sentences_list)for sentence in sentences_list:    print(sentence)