【Python】正则表达式 .*? 的简单使用

简单来说，正则表达式的 .*? 可以匹配任意字符串，例子如下：
数据的结构长这样：
代码：
#coding=utf-8
import re
from bs4 import BeautifulSoup

mystr2 = '<ul><li class="" data-rid="1"><a class="channel" href="//www.qidian.com/dushi" target="_blank" data-eid="qd_A102"><em>「</em>都市<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027334219" target="_blank" data-eid="qd_A103" data-bid="1027334219" title="天天中奖">天天中奖</a><cite class="hot"></cite></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=2852726" data-eid="qd_A104" target="_blank">云罱</a></li><li class="" data-rid="2"><a class="channel" href="//www.qidian.com/qihuan" target="_blank" data-eid="qd_A102"><em>「</em>奇幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027961464" target="_blank" data-eid="qd_A103" data-bid="1027961464" title="黑夜眷者">黑夜眷者</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=9588053" data-eid="qd_A104" target="_blank">中二的菌菇</a></li><li class="" data-rid="3"><a class="channel" href="//www.qidian.com/dushi" target="_blank" data-eid="qd_A102"><em>「</em>都市<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027574123" target="_blank" data-eid="qd_A103" data-bid="1027574123" title="别叫我顶流">别叫我顶流</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=8138524" data-eid="qd_A104" target="_blank">夜夜烨烨</a></li><li class="" data-rid="4"><a class="channel" href="//www.qidian.com/xianxia" target="_blank" data-eid="qd_A102"><em>「</em>仙侠<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027724401" target="_blank" data-eid="qd_A103" data-bid="1027724401" title="玄门不正宗">玄门不正宗</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=9057974" data-eid="qd_A104" target="_blank">愁啊愁</a></li><li class="" data-rid="5"><a class="channel" href="//www.qidian.com/kehuan" target="_blank" data-eid="qd_A102"><em>「</em>科幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027857957" target="_blank" data-eid="qd_A103" data-bid="1027857957" title="这个北宋有点怪">这个北宋有点怪</a><cite class="hot"></cite></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=29652" data-eid="qd_A104" target="_blank">翔炎</a></li><li class="" data-rid="6"><a class="channel" href="//www.qidian.com/kehuan" target="_blank" data-eid="qd_A102"><em>「</em>科幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027710528" target="_blank" data-eid="qd_A103" data-bid="1027710528" title="影视世界学才艺">影视世界学才艺</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=402401261" data-eid="qd_A104" target="_blank">寸夕日</a></li><li class="" data-rid="7"><a class="channel" href="//www.qidian.com/dushi" target="_blank" data-eid="qd_A102"><em>「</em>都市<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1028140933" target="_blank" data-eid="qd_A103" data-bid="1028140933" title="重生之孝看人生">重生之孝看人生</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=400339097" data-eid="qd_A104" target="_blank">皇家雇佣猫</a></li><li class="str3" data-rid="8"><a class="channel" href="//www.qidian.com/2cy" target="_blank" data-eid="qd_A102"><em>「</em>轻小说<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1024216142" target="_blank" data-eid="qd_A103" data-bid="1024216142" title="在木叶开地下城">在木叶开地下城</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=430543775" data-eid="qd_A104" target="_blank">红丸辣椒酱</a></li><li class="" data-rid="9"><a class="channel" href="//www.qidian.com/kehuan" target="_blank" data-eid="qd_A102"><em>「</em>科幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027697434" target="_blank" data-eid="qd_A103" data-bid="1027697434" title="民间黑科技大佬">民间黑科技大佬</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=430546303" data-eid="qd_A104" target="_blank">蚂蚁吃萝卜</a></li><li class="" data-rid="10"><a class="channel" href="//www.qidian.com/kehuan" target="_blank" data-eid="qd_A102"><em>「</em>科幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027860577" target="_blank" data-eid="qd_A103" data-bid="1027860577" title="诸天世界唯一玩家">诸天世界唯一玩家</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=10627245" data-eid="qd_A104" target="_blank">永恒的恒星</a></li><li class="" data-rid="11"><a class="channel" href="//www.qidian.com/xuanhuan" target="_blank" data-eid="qd_A102"><em>「</em>玄幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027996625" target="_blank" data-eid="qd_A103" data-bid="1027996625" title="斗罗大陆V重生唐三">斗罗大陆V重生唐三</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=4921" data-eid="qd_A104" target="_blank">唐家三少</a></li><li class="" data-rid="12"><a class="channel" href="//www.qidian.com/kehuan" target="_blank" data-eid="qd_A102"><em>「</em>科幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027474018" target="_blank" data-eid="qd_A103" data-bid="1027474018" title="诸天穿越从龙蛇开始">诸天穿越从龙蛇开始</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=430503963" data-eid="qd_A104" target="_blank">屠鸡剑神</a></li><li class="" data-rid="13"><a class="channel" href="//www.qidian.com/kehuan" target="_blank" data-eid="qd_A102"><em>「</em>科幻<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1028100462" target="_blank" data-eid="qd_A103" data-bid="1028100462" title="影视世界从小舍得开始">影视世界从小舍得开始</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=430559705" data-eid="qd_A104" target="_blank">山俪</a></li><li class="str3" data-rid="14"><a class="channel" href="//www.qidian.com/2cy" target="_blank" data-eid="qd_A102"><em>「</em>轻小说<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1028095913" target="_blank" data-eid="qd_A103" data-bid="1028095913" title="男生宿舍，女生止步！">男生宿舍，女生止步！</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=10877310" data-eid="qd_A104" target="_blank">老翻译家</a></li><li class="" data-rid="15"><a class="channel" href="//www.qidian.com/xianxia" target="_blank" data-eid="qd_A102"><em>「</em>仙侠<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1028082739" target="_blank" data-eid="qd_A103" data-bid="1028082739" title="我在茶楼酒肆说书的那些年">我在茶楼酒肆说书的那些年</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=430174122" data-eid="qd_A104" target="_blank">鸭不先知</a></li><li class="" data-rid="16"><a class="channel" href="//www.qidian.com/xianxia" target="_blank" data-eid="qd_A102"><em>「</em>仙侠<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1028121685" target="_blank" data-eid="qd_A103" data-bid="1028121685" title="长生志异，开局菜市口被斩首">长生志异，开局菜市口被斩首</a><cite class="hot"></cite></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=402352953" data-eid="qd_A104" target="_blank">真愚老人</a></li><li class="" data-rid="17"><a class="channel" href="//www.qidian.com/dushi" target="_blank" data-eid="qd_A102"><em>「</em>都市<em>」</em></a><strong><a class="name" href="//book.qidian.com/info/1027681790" target="_blank" data-eid="qd_A103" data-bid="1027681790" title="我还没上台，经纪公司就倒闭了">我还没上台，经纪公司就倒闭了</a></strong><a class="author" href="//me.qidian.com/authorIndex.aspx?id=430295861" data-eid="qd_A104" target="_blank">南天有雪</a></li><li data-rid="18"><a class="channel" href="http://game.qidian.com/index.aspx" target="_blank" data-eid="qd_A106"><em>「</em>页游<em>」</em></a><a class="name" href="https://game.qidian.com/Game/Play/index?gameId=201120&amp;qd_game_key=tjj-8&amp;qd_dd_p1=87464" target="_blank" data-eid="qd_A106" data-qd_dd_p1="1">送无限充值卡</a><span class="author">广告</span></li></ul>'
soup = BeautifulSoup(mystr2,"lxml")#"lxml"也可换为"html.parser"

name =re.compile(r'<a class=".*?" href=".*?" data-eid=".*?" target="_blank">(.*?)</a>')
href = re.compile(r'<a class="channel" data-eid=".*?" href="(.*?)" target=".*?"><em>「</em>.*?<em>」</em></a>')
print(href.findall(str(soup)))#符合href条件的链接
print(name.findall(str(soup)))#符合name条件的名字
print(soup.find_all("a",href = re.compile(r"//www.*")))#符合href="//www"条件的所有a标签