{"id":779,"date":"2012-04-15T00:40:35","date_gmt":"2012-04-14T16:40:35","guid":{"rendered":"http:\/\/nick.workao.org\/?p=779"},"modified":"2012-04-15T00:46:43","modified_gmt":"2012-04-14T16:46:43","slug":"python%e6%ad%a3%e5%88%99%e8%a1%a8%e8%be%be%e5%bc%8f%e6%93%8d%e4%bd%9c%e6%8c%87%e5%8d%97","status":"publish","type":"post","link":"https:\/\/nick.txtcc.com\/index.php\/linux\/779","title":{"rendered":"Python\u6b63\u5219\u8868\u8fbe\u5f0f\u64cd\u4f5c\u6307\u5357"},"content":{"rendered":"<p><strong> \u6458\u8981 <\/strong>\n\u672c\u6587\u662f\u901a\u8fc7Python\u7684 re \u6a21\u5757\u6765\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u4e00\u4e2a\u5165\u95e8\u6559\u7a0b\uff0c\u548c\u5e93\u53c2\u8003\u624b\u518c\u7684\u5bf9\u5e94\u7ae0\u8282\u76f8\u6bd4\uff0c\u66f4\u4e3a\u6d45\u663e\u6613\u61c2\u3001\u5faa\u5e8f\u6e10\u8fdb\u3002<\/p>\n<p>\u672c\u6587\u53ef\u4ee5\u4ece <a title=\"http:\/\/www.amk.ca\/python\/howto\" href=\"http:\/\/www.amk.ca\/python\/howto\" rel=\"nofollow\"><a href=\"http:\/\/www.amk.ca\/python\/howto\">http:\/\/www.amk.ca\/python\/howto<\/a><\/a> \u6355\u83b7\n<strong> \u76ee\u5f55 <\/strong><\/p>\n<p>&nbsp;<\/p>\n<table id=\"toc\" summary=\"\u76ee\u5f55\">\n<tbody>\n<tr>\n<td>\n<div id=\"toctitle\">\n<h2>\u76ee\u5f55<\/h2>\n[<a id=\"togglelink\">\u9690\u85cf<\/a>]\n\n<\/div>\n<ul>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E7.AE.80.E4.BB.8B\">1 \u7b80\u4ecb<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E7.AE.80.E5.8D.95.E6.A8.A1.E5.BC.8F\">2 \u7b80\u5355\u6a21\u5f0f<\/a>\n<ul>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.AD.97.E7.AC.A6.E5.8C.B9.E9.85.8D\">2.1 \u5b57\u7b26\u5339\u914d<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E9.87.8D.E5.A4.8D\">2.2 \u91cd\u590d<\/a><\/li>\n<\/ul>\n<\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E4.BD.BF.E7.94.A8.E6.AD.A3.E5.88.99.E8.A1.A8.E8.BE.BE.E5.BC.8F\">3 \u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f<\/a>\n<ul>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E7.BC.96.E8.AF.91.E6.AD.A3.E5.88.99.E8.A1.A8.E8.BE.BE.E5.BC.8F\">3.1 \u7f16\u8bd1\u6b63\u5219\u8868\u8fbe\u5f0f<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.8F.8D.E6.96.9C.E6.9D.A0.E7.9A.84.E9.BA.BB.E7.83.A6\">3.2 \u53cd\u659c\u6760\u7684\u9ebb\u70e6<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E6.89.A7.E8.A1.8C.E5.8C.B9.E9.85.8D\">3.3 \u6267\u884c\u5339\u914d<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E6.A8.A1.E5.9D.97.E7.BA.A7.E5.87.BD.E6.95.B0\">3.4 \u6a21\u5757\u7ea7\u51fd\u6570<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E7.BC.96.E8.AF.91.E6.A0.87.E5.BF.97\">3.5 \u7f16\u8bd1\u6807\u5fd7<\/a><\/li>\n<\/ul>\n<\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E6.9B.B4.E5.A4.9A.E6.A8.A1.E5.BC.8F.E5.8A.9F.E8.83.BD\">4 \u66f4\u591a\u6a21\u5f0f\u529f\u80fd<\/a>\n<ul>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E6.9B.B4.E5.A4.9A.E7.9A.84.E5.85.83.E5.AD.97.E7.AC.A6\">4.1 \u66f4\u591a\u7684\u5143\u5b57\u7b26<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.88.86.E7.BB.84\">4.2 \u5206\u7ec4<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E6.97.A0.E6.8D.95.E8.8E.B7.E7.BB.84.E5.92.8C.E5.91.BD.E5.90.8D.E7.BB.84\">4.3 \u65e0\u6355\u83b7\u7ec4\u548c\u547d\u540d\u7ec4<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.89.8D.E5.90.91.E7.95.8C.E5.AE.9A.E7.AC.A6\">4.4 \u524d\u5411\u754c\u5b9a\u7b26<\/a><\/li>\n<\/ul>\n<\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E4.BF.AE.E6.94.B9.E5.AD.97.E7.AC.A6.E4.B8.B2\">5 \u4fee\u6539\u5b57\u7b26\u4e32<\/a>\n<ul>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.B0.86.E5.AD.97.E7.AC.A6.E4.B8.B2.E5.88.86.E7.89.87\">5.1 \u5c06\u5b57\u7b26\u4e32\u5206\u7247<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E6.90.9C.E7.B4.A2.E5.92.8C.E6.9B.BF.E6.8D.A2\">5.2 \u641c\u7d22\u548c\u66ff\u6362<\/a><\/li>\n<\/ul>\n<\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.B8.B8.E8.A7.81.E9.97.AE.E9.A2.98\">6 \u5e38\u89c1\u95ee\u9898<\/a>\n<ul>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E4.BD.BF.E7.94.A8.E5.AD.97.E7.AC.A6.E4.B8.B2.E6.96.B9.E5.BC.8F\">6.1 \u4f7f\u7528\u5b57\u7b26\u4e32\u65b9\u5f0f<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#match.28.29_vs_search.28.29\">6.2 match() vs search()<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E8.B4.AA.E5.A9.AA_vs_.E4.B8.8D.E8.B4.AA.E5.A9.AA\">6.3 \u8d2a\u5a6a vs \u4e0d\u8d2a\u5a6a<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E4.B8.8D.E7.94.A8_re.VERBOSE\">6.4 \u4e0d\u7528 re.VERBOSE<\/a><\/li>\n<\/ul>\n<\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.8F.8D.E9.A6.88\">7 \u53cd\u9988<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.A4.A7.E6.A0.87.E9.A2.98.E6.96.87.E5.AD.97\">8 \u5927\u6807\u9898\u6587\u5b57<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#.E5.85.B3.E4.BA.8E.E6.9C.AC.E6.96.87.E6.A1.A3\">9 \u5173\u4e8e\u672c\u6587\u6863<\/a><\/li>\n    <li><a href=\"http:\/\/wiki.ubuntu.org.cn\/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97#of_LaTeX2HTML_to_the_Python_documentation\">10 of LaTeX2HTML to the Python documentation<\/a><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><a id=\".E7.AE.80.E4.BB.8B\" name=\".E7.AE.80.E4.BB.8B\"><\/a><\/p>\n<h3>\u7b80\u4ecb<\/h3>\n<p>Python \u81ea1.5\u7248\u672c\u8d77\u589e\u52a0\u4e86re \u6a21\u5757\uff0c\u5b83\u63d0\u4f9b Perl \u98ce\u683c\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u6a21\u5f0f\u3002Python 1.5\u4e4b\u524d\u7248\u672c\u5219\u662f\u901a\u8fc7 regex \u6a21\u5757\u63d0\u4f9b Emacs \u98ce\u683c\u7684\u6a21\u5f0f\u3002Emacs \u98ce\u683c\u6a21\u5f0f\u53ef\u8bfb\u6027\u7a0d\u5dee\u4e9b\uff0c\u800c\u4e14\u529f\u80fd\u4e5f\u4e0d\u5f3a\uff0c\u56e0\u6b64\u7f16\u5199\u65b0\u4ee3\u7801\u65f6\u5c3d\u91cf\u4e0d\u8981\u518d\u4f7f\u7528 regex \u6a21\u5757\uff0c\u5f53\u7136\u5076\u5c14\u4f60\u8fd8\u662f\u53ef\u80fd\u5728\u8001\u4ee3\u7801\u91cc\u53d1\u73b0\u5176\u8e2a\u5f71\u3002\n\u5c31\u5176\u672c\u8d28\u800c\u8a00\uff0c\u6b63\u5219\u8868\u8fbe\u5f0f\uff08\u6216 RE\uff09\u662f\u4e00\u79cd\u5c0f\u578b\u7684\u3001\u9ad8\u5ea6\u4e13\u4e1a\u5316\u7684\u7f16\u7a0b\u8bed\u8a00\uff0c\uff08\u5728Python\u4e2d\uff09\u5b83\u5185\u5d4c\u5728Python\u4e2d\uff0c\u5e76\u901a\u8fc7 re \u6a21\u5757\u5b9e\u73b0\u3002\u4f7f\u7528\u8fd9\u4e2a\u5c0f\u578b\u8bed\u8a00\uff0c\u4f60\u53ef\u4ee5\u4e3a\u60f3\u8981\u5339\u914d\u7684\u76f8\u5e94\u5b57\u7b26\u4e32\u96c6\u6307\u5b9a\u89c4\u5219\uff1b\u8be5\u5b57\u7b26\u4e32\u96c6\u53ef\u80fd\u5305\u542b\u82f1\u6587\u8bed\u53e5\u3001e-mail\u5730\u5740\u3001TeX\u547d\u4ee4\u6216\u4efb\u4f55\u4f60\u60f3\u641e\u5b9a\u7684\u4e1c \u897f\u3002\u7136\u540e\u4f60\u53ef\u4ee5\u95ee\u8bf8\u5982\u201c\u8fd9\u4e2a\u5b57\u7b26\u4e32\u5339\u914d\u8be5\u6a21\u5f0f\u5417\uff1f\u201d\u6216\u201c\u5728\u8fd9\u4e2a\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u6709\u90e8\u5206\u5339\u914d\u8be5\u6a21\u5f0f\u5462\uff1f\u201d\u3002\u4f60\u4e5f\u53ef\u4ee5\u4f7f\u7528 RE 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name=\".E9.87.8D.E5.A4.8D\"><\/a><\/p>\n<h4>\u91cd\u590d<\/h4>\n<p>\u6b63\u5219\u8868\u8fbe\u5f0f\u7b2c\u4e00\u4ef6\u80fd\u505a\u7684\u4e8b\u662f\u80fd\u591f\u5339\u914d\u4e0d\u5b9a\u957f\u7684\u5b57\u7b26\u96c6\uff0c\u800c\u8fd9\u662f\u5176\u5b83\u80fd\u4f5c\u7528\u5728\u5b57\u7b26\u4e32\u4e0a\u7684\u65b9\u6cd5\u6240\u4e0d\u80fd\u505a\u5230\u7684\u3002 \u4e0d\u8fc7\uff0c\u5982\u679c\u90a3\u662f\u6b63\u5219\u8868\u8fbe\u5f0f\u552f\u4e00\u7684\u9644\u52a0\u529f\u80fd\u7684\u8bdd\uff0c\u90a3\u4e48\u5b83\u4eec\u4e5f\u5c31\u4e0d\u90a3\u4e48\u4f18\u79c0\u4e86\u3002\u5b83\u4eec\u7684\u53e6\u4e00\u4e2a\u529f\u80fd\u5c31\u662f\u4f60\u53ef\u4ee5\u6307\u5b9a\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u4e00\u90e8\u5206\u7684\u91cd\u590d\u6b21\u6570\u3002<\/p>\n<p>\u6211\u4eec\u8ba8\u8bba\u7684\u7b2c\u4e00\u4e2a\u91cd\u590d\u529f\u80fd\u7684\u5143\u5b57\u7b26\u662f <em>\u3002<\/em> \u5e76\u4e0d\u5339\u914d\u5b57\u6bcd\u5b57\u7b26 &#8220;*&#8221;\uff1b\u76f8\u53cd\uff0c\u5b83\u6307\u5b9a\u524d\u4e00\u4e2a\u5b57\u7b26\u53ef\u4ee5\u88ab\u5339\u914d\u96f6\u6b21\u6216\u66f4\u591a\u6b21\uff0c\u800c\u4e0d\u662f\u53ea\u6709\u4e00\u6b21\u3002<\/p>\n<p>\u4e3e\u4e2a\u4f8b\u5b50\uff0cca*t \u5c06\u5339\u914d &#8220;ct&#8221; (0 \u4e2a &#8220;a&#8221; \u5b57\u7b26), &#8220;cat&#8221; (1 \u4e2a &#8220;a&#8221;), &#8220;caaat&#8221; (3 \u4e2a &#8220;a&#8221; \u5b57\u7b26)\u7b49\u7b49\u3002RE \u5f15\u64ce\u6709\u5404\u79cd\u6765\u81ea C \u7684\u6574\u6570\u7c7b\u578b\u5927\u5c0f\u7684\u5185\u90e8\u9650\u5236\uff0c\u4ee5\u9632\u6b62\u5b83\u5339\u914d\u8d85\u8fc720\u4ebf\u4e2a &#8220;a&#8221; \u5b57\u7b26\uff1b\u4f60\u4e5f\u8bb8\u6ca1\u6709\u8db3\u591f\u7684\u5185\u5b58\u53bb\u5efa\u9020\u90a3\u4e48\u5927\u7684\u5b57\u7b26\u4e32\uff0c\u6240\u4ee5\u5c06\u4e0d\u4f1a\u7d2f\u8ba1\u5230\u90a3\u4e2a\u9650\u5236\u3002<\/p>\n<p>\u8c61 <em> \u8fd9\u6837\u5730\u91cd\u590d\u662f\u201c\u8d2a\u5a6a\u7684\u201d\uff1b\u5f53\u91cd\u590d\u4e00\u4e2a RE \u65f6\uff0c\u5339\u914d\u5f15\u64ce\u4f1a\u8bd5\u7740\u91cd\u590d\u5c3d\u53ef\u80fd\u591a\u7684\u6b21\u6570\u3002\u5982\u679c\u6a21\u5f0f\u7684\u540e\u9762\u90e8\u5206\u6ca1\u6709\u88ab\u5339\u914d\uff0c\u5339\u914d\u5f15\u64ce\u5c06\u9000\u56de\u5e76\u518d\u6b21\u5c1d\u8bd5\u66f4\u5c0f\u7684\u91cd\u590d\u3002\n\u4e00\u6b65\u6b65\u7684\u793a\u4f8b\u53ef\u4ee5\u4f7f\u5b83\u66f4\u52a0\u6e05\u6670\u3002\u8ba9\u6211\u4eec\u8003\u8651\u8868\u8fbe\u5f0f a[bcd]<\/em>b\u3002\u5b83\u5339\u914d\u5b57\u6bcd &#8220;a&#8221;\uff0c\u96f6\u4e2a\u6216\u66f4\u591a\u4e2a\u6765\u81ea\u7c7b [bcd]\u4e2d\u7684\u5b57\u6bcd\uff0c\u6700\u540e\u4ee5 &#8220;b&#8221; \u7ed3\u5c3e\u3002\u73b0\u5728\u60f3\u4e00\u60f3\u8be5 RE \u5bf9\u5b57\u7b26\u4e32 &#8220;abcbd&#8221; \u7684\u5339\u914d\u3002<\/p>\n<table border=\"1\" cellspacing=\"0\">\n<tbody>\n<tr>\n<td>Step<\/td>\n<td>Matched<\/td>\n<td>Explanation<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>a<\/td>\n<td>a \u5339\u914d\u6a21\u5f0f<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>abcbd<\/td>\n<td>\u5f15\u64ce\u5339\u914d [bcd]*\uff0c\u5e76\u5c3d\u5176\u6240\u80fd\u5339\u914d\u5230\u5b57\u7b26\u4e32\u7684\u7ed3\u5c3e<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>Failure<\/td>\n<td>\u5f15\u64ce\u5c1d\u8bd5\u5339\u914d b\uff0c\u4f46\u5f53\u524d\u4f4d\u7f6e\u5df2\u7ecf\u662f\u5b57\u7b26\u7684\u6700\u540e\u4e86\uff0c\u6240\u4ee5\u5931\u8d25<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td>abcb<\/td>\n<td>\u9000\u56de\uff0c[bcd]*\u5c1d\u8bd5\u5c11\u5339\u914d\u4e00\u4e2a\u5b57\u7b26\u3002<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td>Failure<\/td>\n<td>\u518d\u6b21\u5c1d\u6b21b\uff0c\u4f46\u5728\u5f53\u524d\u6700\u540e\u4e00\u4f4d\u5b57\u7b26\u662f&#8221;d&#8221;\u3002<\/td>\n<\/tr>\n<tr>\n<td>6<\/td>\n<td>abc<\/td>\n<td>\u518d\u6b21\u9000\u56de\uff0c[bcd]*\u53ea\u5339\u914d &#8220;bc&#8221;\u3002<\/td>\n<\/tr>\n<tr>\n<td>7<\/td>\n<td>abcb<\/td>\n<td>\u518d\u6b21\u5c1d\u8bd5 b \uff0c\u8fd9\u6b21\u5f53\u524d\u4f4d\u4e0a\u7684\u5b57\u7b26\u6b63\u597d\u662f &#8220;b&#8221;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>RE \u7684\u7ed3\u5c3e\u90e8\u5206\u73b0\u5728\u53ef\u4ee5\u5230\u8fbe\u4e86\uff0c\u5b83\u5339\u914d &#8220;abcb&#8221;\u3002\u8fd9\u8bc1\u660e\u4e86\u5339\u914d\u5f15\u64ce\u4e00\u5f00\u59cb\u4f1a\u5c3d\u5176\u6240\u80fd\u8fdb\u884c\u5339\u914d\uff0c\u5982\u679c\u6ca1\u6709\u5339\u914d\u7136\u540e\u5c31\u9010\u6b65\u9000\u56de\u5e76\u53cd\u590d\u5c1d\u8bd5 RE \u5269\u4e0b\u6765\u7684\u90e8\u5206\u3002\u76f4\u5230\u5b83\u9000\u56de\u5c1d\u8bd5\u5339\u914d [bcd] \u5230\u96f6\u6b21\u4e3a\u6b62\uff0c\u5982\u679c\u968f\u540e\u8fd8\u662f\u5931\u8d25\uff0c\u90a3\u4e48\u5f15\u64ce\u5c31\u4f1a\u8ba4\u4e3a\u8be5\u5b57\u7b26\u4e32\u6839\u672c\u65e0\u6cd5\u5339\u914d RE \u3002\n\u53e6\u4e00\u4e2a\u91cd\u590d\u5143\u5b57\u7b26\u662f +\uff0c\u8868\u793a\u5339\u914d\u4e00\u6216\u66f4\u591a\u6b21\u3002\u8bf7\u6ce8\u610f <em> \u548c + \u4e4b\u95f4\u7684\u4e0d\u540c\uff1b\uff0a \u5339\u914d\u96f6\u6216\u66f4\u591a\u6b21\uff0c\u6240\u4ee5\u53ef\u4ee5\u6839\u672c\u5c31\u4e0d\u51fa\u73b0\uff0c\u800c + \u5219\u8981\u6c42\u81f3\u5c11\u51fa\u73b0\u4e00\u6b21\u3002\u7528\u540c\u4e00\u4e2a\u4f8b\u5b50\uff0cca+t \u5c31\u53ef\u4ee5\u5339\u914d &#8220;cat&#8221; (1 \u4e2a &#8220;a&#8221;)\uff0c &#8220;caaat&#8221; (3 \u4e2a &#8220;a&#8221;)\uff0c \u4f46\u4e0d\u80fd\u5339\u914d &#8220;ct&#8221;\u3002\n\u8fd8\u6709\u66f4\u591a\u7684\u9650\u5b9a\u7b26\u3002\u95ee\u53f7\u00a0? \u5339\u914d\u4e00\u6b21\u6216\u96f6\u6b21\uff1b\u4f60\u53ef\u4ee5\u8ba4\u4e3a\u5b83\u7528\u4e8e\u6807\u8bc6\u67d0\u4e8b\u7269\u662f\u53ef\u9009\u7684\u3002\u4f8b\u5982\uff1ahome-?brew \u5339\u914d &#8220;homebrew&#8221; \u6216 &#8220;home-brew&#8221;\u3002\n\u6700\u590d\u6742\u7684\u91cd\u590d\u9650\u5b9a\u7b26\u662f {m,n}\uff0c\u5176\u4e2d m \u548c n \u662f\u5341\u8fdb\u5236\u6574\u6570\u3002\u8be5\u9650\u5b9a\u7b26\u7684\u610f\u601d\u662f\u81f3\u5c11\u6709 m \u4e2a\u91cd\u590d\uff0c\u81f3\u591a\u5230 n \u4e2a\u91cd\u590d\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0ca\/{1,3}b \u5c06\u5339\u914d &#8220;a\/b&#8221;\uff0c&#8221;a\/\/b&#8221; \u548c &#8220;a\/\/\/b&#8221;\u3002\u5b83\u4e0d\u80fd\u5339\u914d &#8220;ab&#8221; \u56e0\u4e3a\u6ca1\u6709\u659c\u6760\uff0c\u4e5f\u4e0d\u80fd\u5339\u914d &#8220;a\/\/\/\/b&#8221; \uff0c\u56e0\u4e3a\u6709\u56db\u4e2a\u3002\n\u4f60\u53ef\u4ee5\u5ffd\u7565 m \u6216 n\uff1b\u56e0\u4e3a\u4f1a\u4e3a\u7f3a\u5931\u7684\u503c\u5047\u8bbe\u4e00\u4e2a\u5408\u7406\u7684\u503c\u3002\u5ffd\u7565 m \u4f1a\u8ba4\u4e3a\u4e0b\u8fb9\u754c\u662f 0\uff0c\u800c\u5ffd\u7565 n \u7684\u7ed3\u679c\u5c06\u662f\u4e0a\u8fb9\u754c\u4e3a\u65e0\u7a77\u5927 &#8212; \u5b9e\u9645\u4e0a\u662f\u5148\u524d\u6211\u4eec\u63d0\u5230\u768420\u4ebf\uff0c\u4f46\u8fd9\u4e5f\u8bb8\u540c\u65e0\u7a77\u5927\u4e00\u6837\u3002\n\u7ec6\u5fc3\u7684\u8bfb\u8005\u4e5f\u8bb8\u6ce8\u610f\u5230\u5176\u4ed6\u4e09\u4e2a\u9650\u5b9a\u7b26\u90fd\u53ef\u4ee5\u7528\u8fd9\u6837\u65b9\u5f0f\u6765\u8868\u793a\u3002 {0,} \u7b49\u540c\u4e8e <\/em>\uff0c{1,} \u7b49\u540c\u4e8e +\uff0c\u800c{0,1}\u5219\u4e0e\u00a0? \u76f8\u540c\u3002\u5982\u679c\u53ef\u4ee5\u7684\u8bdd\uff0c\u6700\u597d\u4f7f\u7528 *\uff0c+\uff0c\u6216?\u3002\u5f88\u7b80\u5355\u56e0\u4e3a\u5b83\u4eec\u66f4\u77ed\u4e5f\u66f4\u5bb9\u6613\u61c2\u3002<\/p>\n<p><a id=\".E4.BD.BF.E7.94.A8.E6.AD.A3.E5.88.99.E8.A1.A8.E8.BE.BE.E5.BC.8F\" name=\".E4.BD.BF.E7.94.A8.E6.AD.A3.E5.88.99.E8.A1.A8.E8.BE.BE.E5.BC.8F\"><\/a><\/p>\n<h3>\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f<\/h3>\n<p>\u73b0\u5728\u6211\u4eec\u5df2\u7ecf\u770b\u4e86\u4e00\u4e9b\u7b80\u5355\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\uff0c\u90a3\u4e48\u6211\u4eec\u5b9e\u9645\u5728 Python \u4e2d\u662f\u5982\u4f55\u4f7f\u7528\u5b83\u4eec\u7684\u5462\uff1f re \u6a21\u5757\u63d0\u4f9b\u4e86\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u5f15\u64ce\u7684\u63a5\u53e3\uff0c\u53ef\u4ee5\u8ba9\u4f60\u5c06 REs \u7f16\u8bd1\u6210\u5bf9\u8c61\u5e76\u7528\u5b83\u4eec\u6765\u8fdb\u884c\u5339\u914d\u3002<\/p>\n<p><a id=\".E7.BC.96.E8.AF.91.E6.AD.A3.E5.88.99.E8.A1.A8.E8.BE.BE.E5.BC.8F\" name=\".E7.BC.96.E8.AF.91.E6.AD.A3.E5.88.99.E8.A1.A8.E8.BE.BE.E5.BC.8F\"><\/a><\/p>\n<h4>\u7f16\u8bd1\u6b63\u5219\u8868\u8fbe\u5f0f<\/h4>\n<p>\u6b63\u5219\u8868\u8fbe\u5f0f\u88ab\u7f16\u8bd1\u6210 <code>RegexObject<\/code> \u5b9e\u4f8b\uff0c\u53ef\u4ee5\u4e3a\u4e0d\u540c\u7684\u64cd\u4f5c\u63d0\u4f9b\u65b9\u6cd5\uff0c\u5982\u6a21\u5f0f\u5339\u914d\u641c\u7d22\u6216\u5b57\u7b26\u4e32\u66ff\u6362\u3002<\/p>\n<pre>#!python\n>>> import re\n>>> p = re.compile('ab*')\n>>> print p\n<re.RegexObject instance at 80b4150><\/pre>\n<p>re.compile() \u4e5f\u63a5\u53d7\u53ef\u9009\u7684\u6807\u5fd7\u53c2\u6570\uff0c\u5e38\u7528\u6765\u5b9e\u73b0\u4e0d\u540c\u7684\u7279\u6b8a\u529f\u80fd\u548c\u8bed\u6cd5\u53d8\u66f4\u3002\u6211\u4eec\u7a0d\u540e\u5c06\u67e5\u770b\u6240\u6709\u53ef\u7528\u7684\u8bbe\u7f6e\uff0c\u4f46\u73b0\u5728\u53ea\u4e3e\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<pre>#!python\n>>> p = re.compile('ab*', re.IGNORECASE)<\/pre>\n<p>RE \u88ab\u505a\u4e3a\u4e00\u4e2a\u5b57\u7b26\u4e32\u53d1\u9001\u7ed9 re.compile()\u3002REs \u88ab\u5904\u7406\u6210\u5b57\u7b26\u4e32\u662f\u56e0\u4e3a\u6b63\u5219\u8868\u8fbe\u5f0f\u4e0d\u662f Python \u8bed\u8a00\u7684\u6838\u5fc3\u90e8\u5206\uff0c\u4e5f\u6ca1\u6709\u4e3a\u5b83\u521b\u5efa\u7279\u5b9a\u7684\u8bed\u6cd5\u3002\uff08\u5e94\u7528\u7a0b\u5e8f\u6839\u672c\u5c31\u4e0d\u9700\u8981 REs\uff0c\u56e0\u6b64\u6ca1\u5fc5\u8981\u5305\u542b\u5b83\u4eec\u53bb\u4f7f\u8bed\u8a00\u8bf4\u660e\u53d8\u5f97\u81c3\u80bf\u4e0d\u582a\u3002\uff09\u800c re \u6a21\u5757\u5219\u53ea\u662f\u4ee5\u4e00\u4e2a C \u6269\u5c55\u6a21\u5757\u7684\u5f62\u5f0f\u6765\u88ab Python \u5305\u542b\uff0c\u5c31\u8c61 socket \u6216 zlib \u6a21\u5757\u4e00\u6837\n\u5c06 REs \u4f5c\u4e3a\u5b57\u7b26\u4e32\u4ee5\u4fdd\u8bc1 Python \u8bed\u8a00\u7684\u7b80\u6d01\uff0c\u4f46\u8fd9\u6837\u5e26\u6765\u7684\u4e00\u4e2a\u9ebb\u70e6\u5c31\u662f\u8c61\u4e0b\u8282\u6807\u9898\u6240\u8bb2\u7684\u3002<\/p>\n<p><a id=\".E5.8F.8D.E6.96.9C.E6.9D.A0.E7.9A.84.E9.BA.BB.E7.83.A6\" name=\".E5.8F.8D.E6.96.9C.E6.9D.A0.E7.9A.84.E9.BA.BB.E7.83.A6\"><\/a><\/p>\n<h4>\u53cd\u659c\u6760\u7684\u9ebb\u70e6<\/h4>\n<p>\u5728\u65e9\u671f\u89c4\u5b9a\u4e2d\uff0c\u6b63\u5219\u8868\u8fbe\u5f0f\u7528\u53cd\u659c\u6760\u5b57\u7b26 (&#8220;\\&#8221;) \u6765\u8868\u793a\u7279\u6b8a\u683c\u5f0f\u6216\u5141\u8bb8\u4f7f\u7528\u7279\u6b8a\u5b57\u7b26\u800c\u4e0d\u8c03\u7528\u5b83\u7684\u7279\u6b8a\u7528\u6cd5\u3002\u8fd9\u5c31\u4e0e Python \u5728\u5b57\u7b26\u4e32\u4e2d\u7684\u90a3\u4e9b\u8d77\u76f8\u540c\u4f5c\u7528\u7684\u76f8\u540c\u5b57\u7b26\u4ea7\u751f\u4e86\u51b2\u7a81\u3002\n\u8ba9\u6211\u4eec\u4e3e\u4f8b\u8bf4\u660e\uff0c\u4f60\u60f3\u5199\u4e00\u4e2a RE \u4ee5\u5339\u914d\u5b57\u7b26\u4e32 &#8220;\\section&#8221;\uff0c\u53ef\u80fd\u662f\u5728\u4e00\u4e2a LATEX \u6587\u4ef6\u67e5\u627e\u3002\u4e3a\u4e86\u8981\u5728\u7a0b\u5e8f\u4ee3\u7801\u4e2d\u5224\u65ad\uff0c\u9996\u5148\u8981\u5199\u51fa\u60f3\u8981\u5339\u914d\u7684\u5b57\u7b26\u4e32\u3002\u63a5\u4e0b\u6765\u4f60\u9700\u8981\u5728\u6240\u6709\u53cd\u659c\u6760\u548c\u5176\u5b83\u5143\u5b57\u7b26\u524d\u52a0\u53cd\u659c\u6760\u6765\u53d6\u6d88\u5176\u7279\u6b8a\u610f\u4e49\uff0c\u7ed3\u679c\u8981\u5339\u914d\u7684\u5b57\u7b26\u4e32 \u5c31\u6210\u4e86&#8221;\\section&#8221;\u3002 \u5f53\u628a\u8fd9\u4e2a\u5b57\u7b26\u4e32\u4f20\u9012\u7ed9re.compile()\u65f6\u5fc5\u987b\u8fd8\u662f&#8221;\\section&#8221;\u3002\u7136\u800c\uff0c\u4f5c\u4e3aPython\u7684\u5b57\u7b26\u4e32\u5b9e\u503c(string literals)\u6765\u8868\u793a\u7684\u8bdd\uff0c&#8221;\\section&#8221;\u4e2d\u4e24\u4e2a\u53cd\u659c\u6760\u8fd8\u8981\u518d\u6b21\u53d6\u6d88\u7279\u6b8a\u610f\u4e49\uff0c\u6700\u540e\u7ed3\u679c\u5c31\u53d8\u6210\u4e86&#8221;\\\\section&#8221;\u3002<\/p>\n<table border=\"1\" cellspacing=\"0\">\n<tbody>\n<tr>\n<td>\u5b57\u7b26<\/td>\n<td>\u9636\u6bb5<\/td>\n<\/tr>\n<tr>\n<td>\\section<\/td>\n<td>\u8981\u5339\u914d\u7684\u5b57\u7b26\u4e32<\/td>\n<\/tr>\n<tr>\n<td>\\\\section<\/td>\n<td>\u4e3a re.compile \u53d6\u6d88\u53cd\u659c\u6760\u7684\u7279\u6b8a\u610f\u4e49<\/td>\n<\/tr>\n<tr>\n<td>&#8220;\\\\\\\\section&#8221;<\/td>\n<td>\u4e3a&#8221;\\\\section&#8221;\u7684\u5b57\u7b26\u4e32\u5b9e\u503c(string literals)\u53d6\u6d88\u53cd\u659c\u6760\u7684\u7279\u6b8a\u610f\u4e49<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u7b80\u5355\u5730\u8bf4\uff0c\u4e3a\u4e86\u5339\u914d\u4e00\u4e2a\u53cd\u659c\u6760\uff0c\u4e0d\u5f97\u4e0d\u5728 RE \u5b57\u7b26\u4e32\u4e2d\u5199 &#8216;\\\\&#8217;\uff0c\u56e0\u4e3a\u6b63\u5219\u8868\u8fbe\u5f0f\u4e2d\u5fc5\u987b\u662f &#8220;\\&#8221;\uff0c\u800c\u6bcf\u4e2a\u53cd\u659c\u6760\u5728\u5e38\u89c4\u7684 Python \u5b57\u7b26\u4e32\u5b9e\u503c\u4e2d\u5fc5\u987b\u8868\u793a\u6210 &#8220;\\&#8221;\u3002\u5728 REs \u4e2d\u53cd\u659c\u6760\u7684\u8fd9\u4e2a\u91cd\u590d\u7279\u6027\u4f1a\u5bfc\u81f4\u5927\u91cf\u91cd\u590d\u7684\u53cd\u659c\u6760\uff0c\u800c\u4e14\u6240\u751f\u6210\u7684\u5b57\u7b26\u4e32\u4e5f\u5f88\u96be\u61c2\u3002<\/p>\n<p>\u89e3\u51b3\u7684\u529e\u6cd5\u5c31\u662f\u4e3a\u6b63\u5219\u8868\u8fbe\u5f0f\u4f7f\u7528 Python \u7684 raw \u5b57\u7b26\u4e32\u8868\u793a\uff1b\u5728\u5b57\u7b26\u4e32\u524d\u52a0\u4e2a &#8220;r&#8221; \u53cd\u659c\u6760\u5c31\u4e0d\u4f1a\u88ab\u4efb\u4f55\u7279\u6b8a\u65b9\u5f0f\u5904\u7406\uff0c\u6240\u4ee5 r&#8221;\\n&#8221; \u5c31\u662f\u5305\u542b&#8221;\\&#8221; \u548c &#8220;n&#8221; \u7684\u4e24\u4e2a\u5b57\u7b26\uff0c\u800c &#8220;\\n&#8221; \u5219\u662f\u4e00\u4e2a\u5b57\u7b26\uff0c\u8868\u793a\u4e00\u4e2a\u6362\u884c\u3002\u6b63\u5219\u8868\u8fbe\u5f0f\u901a\u5e38\u5728 Python \u4ee3\u7801\u4e2d\u90fd\u662f\u7528\u8fd9\u79cd raw \u5b57\u7b26\u4e32\u8868\u793a\u3002<\/p>\n<table border=\"1\" cellspacing=\"0\">\n<tbody>\n<tr>\n<td>\u5e38\u89c4\u5b57\u7b26\u4e32<\/td>\n<td>Raw \u5b57\u7b26\u4e32<\/td>\n<\/tr>\n<tr>\n<td>&#8220;ab*&#8221;<\/td>\n<td>r&#8221;ab*&#8221;<\/td>\n<\/tr>\n<tr>\n<td>&#8220;\\\\\\\\section&#8221;<\/td>\n<td>r&#8221;\\\\section&#8221;<\/td>\n<\/tr>\n<tr>\n<td>&#8220;\\\\w+\\\\s+\\\\1&#8221;<\/td>\n<td>r&#8221;\\w+\\s+\\1&#8243;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><a id=\".E6.89.A7.E8.A1.8C.E5.8C.B9.E9.85.8D\" name=\".E6.89.A7.E8.A1.8C.E5.8C.B9.E9.85.8D\"><\/a><\/p>\n<h4>\u6267\u884c\u5339\u914d<\/h4>\n<p>\u4e00\u65e6\u4f60\u6709\u4e86\u5df2\u7ecf\u7f16\u8bd1\u4e86\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u5bf9\u8c61\uff0c\u4f60\u8981\u7528\u5b83\u505a\u4ec0\u4e48\u5462\uff1f<code>RegexObject<\/code> \u5b9e\u4f8b\u6709\u4e00\u4e9b\u65b9\u6cd5\u548c\u5c5e\u6027\u3002\u8fd9\u91cc\u53ea\u663e\u793a\u4e86\u6700\u91cd\u8981\u7684\u51e0\u4e2a\uff0c\u5982\u679c\u8981\u770b\u5b8c\u6574\u7684\u5217\u8868\u8bf7\u67e5\u9605 Python Library Reference<\/p>\n<table border=\"1\" cellspacing=\"0\">\n<tbody>\n<tr>\n<td>\u65b9\u6cd5\/\u5c5e\u6027<\/td>\n<td>\u4f5c\u7528<\/td>\n<\/tr>\n<tr>\n<td>match()<\/td>\n<td>\u51b3\u5b9a RE \u662f\u5426\u5728\u5b57\u7b26\u4e32\u521a\u5f00\u59cb\u7684\u4f4d\u7f6e\u5339\u914d<\/td>\n<\/tr>\n<tr>\n<td>search()<\/td>\n<td>\u626b\u63cf\u5b57\u7b26\u4e32\uff0c\u627e\u5230\u8fd9\u4e2a RE \u5339\u914d\u7684\u4f4d\u7f6e<\/td>\n<\/tr>\n<tr>\n<td>findall()<\/td>\n<td>\u627e\u5230 RE \u5339\u914d\u7684\u6240\u6709\u5b50\u4e32\uff0c\u5e76\u628a\u5b83\u4eec\u4f5c\u4e3a\u4e00\u4e2a\u5217\u8868\u8fd4\u56de<\/td>\n<\/tr>\n<tr>\n<td>finditer()<\/td>\n<td>\u627e\u5230 RE \u5339\u914d\u7684\u6240\u6709\u5b50\u4e32\uff0c\u5e76\u628a\u5b83\u4eec\u4f5c\u4e3a\u4e00\u4e2a\u8fed\u4ee3\u5668\u8fd4\u56de<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u5982\u679c\u6ca1\u6709\u5339\u914d\u5230\u7684\u8bdd\uff0cmatch() \u548c search() \u5c06\u8fd4\u56de None\u3002\u5982\u679c\u6210\u529f\u7684\u8bdd\uff0c\u5c31\u4f1a\u8fd4\u56de\u4e00\u4e2a <code>MatchObject<\/code> \u5b9e\u4f8b\uff0c\u5176\u4e2d\u6709\u8fd9\u6b21\u5339\u914d\u7684\u4fe1\u606f\uff1a\u5b83\u662f\u4ece\u54ea\u91cc\u5f00\u59cb\u548c\u7ed3\u675f\uff0c\u5b83\u6240\u5339\u914d\u7684\u5b50\u4e32\u7b49\u7b49\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u4f60\u53ef\u4ee5\u7528\u91c7\u7528\u4eba\u673a\u5bf9\u8bdd\u5e76\u7528 re \u6a21\u5757\u5b9e\u9a8c\u7684\u65b9\u5f0f\u6765\u5b66\u4e60\u5b83\u3002\u5982\u679c\u4f60\u6709 Tkinter \u7684\u8bdd\uff0c\u4f60\u4e5f\u8bb8\u53ef\u4ee5\u8003\u8651\u53c2\u8003\u4e00\u4e0b Tools\/scripts\/redemo.py\uff0c\u4e00\u4e2a\u5305\u542b\u5728 Python \u53d1\u884c\u7248\u91cc\u7684\u793a\u8303\u7a0b\u5e8f\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u9996\u5148\uff0c\u8fd0\u884c Python \u89e3\u91ca\u5668\uff0c\u5bfc\u5165 re \u6a21\u5757\u5e76\u7f16\u8bd1\u4e00\u4e2a RE\uff1a<\/p>\n<pre>#!python\nPython 2.2.2 (#1, Feb 10 2003, 12:57:01)\n>>> import re\n>>> p = re.compile('[a-z]+')\n>>> p\n<_sre.SRE_Pattern object at 80c3c28><\/pre>\n<p>\u73b0\u5728\uff0c\u4f60\u53ef\u4ee5\u8bd5\u7740\u7528 RE \u7684 [a-z]+ \u53bb\u5339\u914d\u4e0d\u540c\u7684\u5b57\u7b26\u4e32\u3002\u4e00\u4e2a\u7a7a\u5b57\u7b26\u4e32\u5c06\u6839\u672c\u4e0d\u80fd\u5339\u914d\uff0c\u56e0\u4e3a + \u7684\u610f\u601d\u662f \u201c\u4e00\u4e2a\u6216\u66f4\u591a\u7684\u91cd\u590d\u6b21\u6570\u201d\u3002 \u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b match() \u5c06\u8fd4\u56de None\uff0c\u56e0\u4e3a\u5b83\u4f7f\u89e3\u91ca\u5668\u6ca1\u6709\u8f93\u51fa\u3002\u4f60\u53ef\u4ee5\u660e\u786e\u5730\u6253\u5370\u51fa match() \u7684\u7ed3\u679c\u6765\u5f04\u6e05\u8fd9\u4e00\u70b9\u3002<\/p>\n<pre>#!python\n>>> p.match(\"\")\n>>> print p.match(\"\")\nNone<\/pre>\n<p>\u73b0\u5728\uff0c\u8ba9\u6211\u4eec\u8bd5\u7740\u7528\u5b83\u6765\u5339\u914d\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u5982 &#8220;tempo&#8221;\u3002\u8fd9\u65f6\uff0cmatch() \u5c06\u8fd4\u56de\u4e00\u4e2a MatchObject\u3002\u56e0\u6b64\u4f60\u53ef\u4ee5\u5c06\u7ed3\u679c\u4fdd\u5b58\u5728\u53d8\u91cf\u91cc\u4ee5\u4fbf\u540e\u9762\u4f7f\u7528\u3002<\/p>\n<pre>#!python\n>>> m = p.match( 'tempo')\n>>> print m\n<_sre.SRE_Match object at 80c4f68><\/pre>\n<p>\u73b0\u5728\u4f60\u53ef\u4ee5\u67e5\u8be2 <code>MatchObject<\/code> \u5173\u4e8e\u5339\u914d\u5b57\u7b26\u4e32\u7684\u76f8\u5173\u4fe1\u606f\u4e86\u3002MatchObject \u5b9e\u4f8b\u4e5f\u6709\u51e0\u4e2a\u65b9\u6cd5\u548c\u5c5e\u6027\uff1b\u6700\u91cd\u8981\u7684\u90a3\u4e9b\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<table border=\"1\" cellspacing=\"0\">\n<tbody>\n<tr>\n<td>\u65b9\u6cd5\/\u5c5e\u6027<\/td>\n<td>\u4f5c\u7528<\/td>\n<\/tr>\n<tr>\n<td>group()<\/td>\n<td>\u8fd4\u56de\u88ab RE \u5339\u914d\u7684\u5b57\u7b26\u4e32<\/td>\n<\/tr>\n<tr>\n<td>start()<\/td>\n<td>\u8fd4\u56de\u5339\u914d\u5f00\u59cb\u7684\u4f4d\u7f6e<\/td>\n<\/tr>\n<tr>\n<td>end()<\/td>\n<td>\u8fd4\u56de\u5339\u914d\u7ed3\u675f\u7684\u4f4d\u7f6e<\/td>\n<\/tr>\n<tr>\n<td>span()<\/td>\n<td>\u8fd4\u56de\u4e00\u4e2a\u5143\u7ec4\u5305\u542b\u5339\u914d (\u5f00\u59cb,\u7ed3\u675f) \u7684\u4f4d\u7f6e<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u8bd5\u8bd5\u8fd9\u4e9b\u65b9\u6cd5\u4e0d\u4e45\u5c31\u4f1a\u6e05\u695a\u5b83\u4eec\u7684\u4f5c\u7528\u4e86\uff1a<\/p>\n<pre>#!python\n>>> m.group()\n'tempo'\n>>> m.start(), m.end()\n(0, 5)\n>>> m.span()\n(0, 5)<\/pre>\n<p>group() \u8fd4\u56de RE \u5339\u914d\u7684\u5b50\u4e32\u3002start() \u548c end() \u8fd4\u56de\u5339\u914d\u5f00\u59cb\u548c\u7ed3\u675f\u65f6\u7684\u7d22\u5f15\u3002span() \u5219\u7528\u5355\u4e2a\u5143\u7ec4\u628a\u5f00\u59cb\u548c\u7ed3\u675f\u65f6\u7684\u7d22\u5f15\u4e00\u8d77\u8fd4\u56de\u3002\u56e0\u4e3a\u5339\u914d\u65b9\u6cd5\u68c0\u67e5\u5230\u5982\u679c RE \u5728\u5b57\u7b26\u4e32\u5f00\u59cb\u5904\u5f00\u59cb\u5339\u914d\uff0c\u90a3\u4e48 start() \u5c06\u603b\u662f\u4e3a\u96f6\u3002\u7136\u800c\uff0c <code>RegexObject<\/code> \u5b9e\u4f8b\u7684 search \u65b9\u6cd5\u626b\u63cf\u4e0b\u9762\u7684\u5b57\u7b26\u4e32\u7684\u8bdd\uff0c\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5339\u914d\u5f00\u59cb\u7684\u4f4d\u7f6e\u5c31\u4e5f\u8bb8\u4e0d\u662f\u96f6\u4e86\u3002<\/p>\n<pre>#!python\n>>> print p.match('::: message')\nNone\n>>> m = p.search('::: message')\u00a0; print m\n<re.MatchObject instance at 80c9650>\n>>> m.group()\n'message'\n>>> m.span()\n(4, 11)<\/pre>\n<p>\u5728\u5b9e\u9645\u7a0b\u5e8f\u4e2d\uff0c\u6700\u5e38\u89c1\u7684\u4f5c\u6cd5\u662f\u5c06 <code>MatchObject<\/code> \u4fdd\u5b58\u5728\u4e00\u4e2a\u53d8\u91cf\u91cc\uff0c\u7136\u540e\u68c0\u67e5\u5b83\u662f\u5426\u4e3a None\uff0c\u901a\u5e38\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre>#!python\np = re.compile( ... )\nm = p.match( 'string goes here' )\nif m:\nprint 'Match found: ', m.group()\nelse:\nprint 'No match'<\/pre>\n<p>\u4e24\u4e2a <code>RegexObject<\/code> \u65b9\u6cd5\u8fd4\u56de\u6240\u6709\u5339\u914d\u6a21\u5f0f\u7684\u5b50\u4e32\u3002findall()\u8fd4\u56de\u4e00\u4e2a\u5339\u914d\u5b57\u7b26\u4e32\u884c\u8868\uff1a<\/p>\n<pre>#!python\n>>> p = re.compile('\\d+')\n>>> p.findall('12 drummers drumming, 11 pipers piping, 10 lords a-leaping')\n['12', '11', '10']<\/pre>\n<p>findall() \u5728\u5b83\u8fd4\u56de\u7ed3\u679c\u65f6\u4e0d\u5f97\u4e0d\u521b\u5efa\u4e00\u4e2a\u5217\u8868\u3002\u5728 Python 2.2\u4e2d\uff0c\u4e5f\u53ef\u4ee5\u7528 finditer() \u65b9\u6cd5\u3002<\/p>\n<pre>#!python\n>>> iterator = p.finditer('12 drummers drumming, 11 ... 10 ...')\n>>> iterator\n<callable-iterator object at 0x401833ac>\n>>> for match in iterator:\n...     print match.span()\n...\n(0, 2)\n(22, 24)\n(29, 31)<\/pre>\n<p><a id=\".E6.A8.A1.E5.9D.97.E7.BA.A7.E5.87.BD.E6.95.B0\" name=\".E6.A8.A1.E5.9D.97.E7.BA.A7.E5.87.BD.E6.95.B0\"><\/a><\/p>\n<h4>\u6a21\u5757\u7ea7\u51fd\u6570<\/h4>\n<p>\u4f60\u4e0d\u4e00\u5b9a\u8981\u4ea7\u751f\u4e00\u4e2a <code>RegexObject<\/code> \u5bf9\u8c61\u7136\u540e\u518d\u8c03\u7528\u5b83\u7684\u65b9\u6cd5\uff1bre \u6a21\u5757\u4e5f\u63d0\u4f9b\u4e86\u9876\u7ea7\u51fd\u6570\u8c03\u7528\u5982 match()\u3001search()\u3001sub() \u7b49\u7b49\u3002\u8fd9\u4e9b\u51fd\u6570\u4f7f\u7528 RE \u5b57\u7b26\u4e32\u4f5c\u4e3a\u7b2c\u4e00\u4e2a\u53c2\u6570\uff0c\u800c\u540e\u9762\u7684\u53c2\u6570\u5219\u4e0e\u76f8\u5e94 <code>RegexObject<\/code> \u7684\u65b9\u6cd5\u53c2\u6570\u76f8\u540c\uff0c\u8fd4\u56de\u5219\u8981\u4e48\u662f None \u8981\u4e48\u5c31\u662f\u4e00\u4e2a <code>MatchObject<\/code> \u7684\u5b9e\u4f8b\u3002<\/p>\n<pre>#!python\n>>> print re.match(r'From\\s+', 'Fromage amk')\nNone\n>>> re.match(r'From\\s+', 'From amk Thu May 14 19:12:10 1998')\n<re.MatchObject instance at 80c5978><\/pre>\n<p>Under the hood, \u8fd9\u4e9b\u51fd\u6570\u7b80\u5355\u5730\u4ea7\u751f\u4e00\u4e2a RegexOject \u5e76\u5728\u5176\u4e0a\u8c03\u7528\u76f8\u5e94\u7684\u65b9\u6cd5\u3002\u5b83\u4eec\u4e5f\u5728\u7f13\u5b58\u91cc\u4fdd\u5b58\u7f16\u8bd1\u540e\u7684\u5bf9\u8c61\uff0c\u56e0\u6b64\u5728\u5c06\u6765\u8c03\u7528\u7528\u5230\u76f8\u540c RE \u65f6\u5c31\u4f1a\u66f4\u5feb\u3002\n\u4f60\u5c06\u4f7f\u7528\u8fd9\u4e9b\u6a21\u5757\u7ea7\u51fd\u6570\uff0c\u8fd8\u662f\u5148\u5f97\u5230\u4e00\u4e2a <code>RegexObject<\/code> \u518d\u8c03\u7528\u5b83\u7684\u65b9\u6cd5\u5462\uff1f\u5982\u4f55\u9009\u62e9\u4f9d\u8d56\u4e8e\u600e\u6837\u7528 RE \u66f4\u6709\u6548\u7387\u4ee5\u53ca\u4f60\u4e2a\u4eba\u7f16\u7801\u98ce\u683c\u3002\u5982\u679c\u4e00\u4e2a RE \u5728\u4ee3\u7801\u4e2d\u53ea\u505a\u7528\u4e00\u6b21\u7684\u8bdd\uff0c\u90a3\u4e48\u6a21\u5757\u7ea7\u51fd\u6570\u4e5f\u8bb8\u66f4\u65b9\u4fbf\u3002\u5982\u679c\u7a0b\u5e8f\u5305\u542b\u5f88\u591a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\uff0c\u6216\u5728\u591a\u5904\u590d\u7528\u540c\u4e00\u4e2a\u7684\u8bdd\uff0c\u90a3\u4e48\u5c06\u5168\u90e8\u5b9a\u4e49\u653e\u5728\u4e00\u8d77\uff0c\u5728\u4e00\u6bb5\u4ee3\u7801\u4e2d\u63d0\u524d \u7f16\u8bd1\u6240\u6709\u7684 REs \u66f4\u6709\u7528\u3002\u4ece\u6807\u51c6\u5e93\u4e2d\u770b\u4e00\u4e2a\u4f8b\u5b50\uff0c\u8fd9\u662f\u4ece xmllib.py \u6587\u4ef6\u4e2d\u63d0\u53d6\u51fa\u6765\u7684\uff1a<\/p>\n<pre>#!python\nref = re.compile( ... )\nentityref = re.compile( ... )\ncharref = re.compile( ... )\nstarttagopen = re.compile( ... )<\/pre>\n<p>\u6211\u901a\u5e38\u66f4\u559c\u6b22\u4f7f\u7528\u7f16\u8bd1\u5bf9\u8c61\uff0c\u751a\u81f3\u5b83\u53ea\u7528\u4e00\u6b21\uff0c\u4f46\u5f88\u5c11\u4eba\u4f1a\u50cf\u6211\u8fd9\u6837\u505a(\u5982\u540c\u4e00\u4e2a\u7eaf\u7cb9\u4e3b\u4e49\u8005)\u3002<\/p>\n<p><a id=\".E7.BC.96.E8.AF.91.E6.A0.87.E5.BF.97\" name=\".E7.BC.96.E8.AF.91.E6.A0.87.E5.BF.97\"><\/a><\/p>\n<h4>\u7f16\u8bd1\u6807\u5fd7<\/h4>\n<p>\u7f16\u8bd1\u6807\u5fd7\u8ba9\u4f60\u53ef\u4ee5\u4fee\u6539\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u4e00\u4e9b\u8fd0\u884c\u65b9\u5f0f\u3002\u5728 re \u6a21\u5757\u4e2d\u6807\u5fd7\u53ef\u4ee5\u4f7f\u7528\u4e24\u4e2a\u540d\u5b57\uff0c\u4e00\u4e2a\u662f\u5168\u540d\u5982 IGNORECASE\uff0c\u4e00\u4e2a\u662f\u7f29\u5199\uff0c\u4e00\u5b57\u6bcd\u5f62\u5f0f\u5982 I\u3002\uff08\u5982\u679c\u4f60\u719f\u6089 Perl \u7684\u6a21\u5f0f\u4fee\u6539\uff0c\u4e00\u5b57\u6bcd\u5f62\u5f0f\u4f7f\u7528\u540c\u6837\u7684\u5b57\u6bcd\uff1b\u4f8b\u5982 re.VERBOSE\u7684\u7f29\u5199\u5f62\u5f0f\u662f re.X\u3002\uff09\u591a\u4e2a\u6807\u5fd7\u53ef\u4ee5\u901a\u8fc7\u6309\u4f4d OR-ing \u5b83\u4eec\u6765\u6307\u5b9a\u3002\u5982 re.I | re.M \u88ab\u8bbe\u7f6e\u6210 I \u548c M \u6807\u5fd7\uff1a\n\u8fd9\u6709\u4e2a\u53ef\u7528\u6807\u5fd7\u8868\uff0c\u5bf9\u6bcf\u4e2a\u6807\u5fd7\u540e\u9762\u90fd\u6709\u8be6\u7ec6\u7684\u8bf4\u660e\u3002<\/p>\n<table border=\"1\" cellspacing=\"0\">\n<tbody>\n<tr>\n<td>\u6807\u5fd7<\/td>\n<td>\u542b\u4e49<\/td>\n<\/tr>\n<tr>\n<td>DOTALL, S<\/td>\n<td>\u4f7f . \u5339\u914d\u5305\u62ec\u6362\u884c\u5728\u5185\u7684\u6240\u6709\u5b57\u7b26<\/td>\n<\/tr>\n<tr>\n<td>IGNORECASE, I<\/td>\n<td>\u4f7f\u5339\u914d\u5bf9\u5927\u5c0f\u5199\u4e0d\u654f\u611f<\/td>\n<\/tr>\n<tr>\n<td>LOCALE, L<\/td>\n<td>\u505a\u672c\u5730\u5316\u8bc6\u522b\uff08locale-aware\uff09\u5339\u914d<\/td>\n<\/tr>\n<tr>\n<td>MULTILINE, M<\/td>\n<td>\u591a\u884c\u5339\u914d\uff0c\u5f71\u54cd ^ \u548c $<\/td>\n<\/tr>\n<tr>\n<td>VERBOSE, X<\/td>\n<td>\u80fd\u591f\u4f7f\u7528 REs \u7684 verbose \u72b6\u6001\uff0c\u4f7f\u4e4b\u88ab\u7ec4\u7ec7\u5f97\u66f4\u6e05\u6670\u6613\u61c2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>I<\/strong>\n<strong>IGNORECASE<\/strong><\/p>\n<p>\u4f7f\u5339\u914d\u5bf9\u5927\u5c0f\u5199\u4e0d\u654f\u611f\uff1b\u5b57\u7b26\u7c7b\u548c\u5b57\u7b26\u4e32\u5339\u914d\u5b57\u6bcd\u65f6\u5ffd\u7565\u5927\u5c0f\u5199\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0c[A-Z]\u4e5f\u53ef\u4ee5\u5339\u914d\u5c0f\u5199\u5b57\u6bcd\uff0cSpam \u53ef\u4ee5\u5339\u914d &#8220;Spam&#8221;, &#8220;spam&#8221;, \u6216 &#8220;spAM&#8221;\u3002\u8fd9\u4e2a\u5c0f\u5199\u5b57\u6bcd\u5e76\u4e0d\u8003\u8651\u5f53\u524d\u4f4d\u7f6e\u3002<\/p>\n<p><strong>L<\/strong>\n<strong>LOCALE<\/strong><\/p>\n<p>\u5f71\u54cd \\w, \\W, \\b, \u548c \\B\uff0c\u8fd9\u53d6\u51b3\u4e8e\u5f53\u524d\u7684\u672c\u5730\u5316\u8bbe\u7f6e\u3002<\/p>\n<p>locales \u662f C \u8bed\u8a00\u5e93\u4e2d\u7684\u4e00\u9879\u529f\u80fd\uff0c\u662f\u7528\u6765\u4e3a\u9700\u8981\u8003\u8651\u4e0d\u540c\u8bed\u8a00\u7684\u7f16\u7a0b\u63d0\u4f9b\u5e2e\u52a9\u7684\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u5982\u679c\u4f60\u6b63\u5728\u5904\u7406\u6cd5\u6587\u6587\u672c\uff0c\u4f60\u60f3\u7528 \\w+ \u6765\u5339\u914d\u6587\u5b57\uff0c\u4f46 \\w \u53ea\u5339\u914d\u5b57\u7b26\u7c7b [A-Za-z]\uff1b\u5b83\u5e76\u4e0d\u80fd\u5339\u914d &#8220;\u00e9&#8221; \u6216 &#8220;\u00e7&#8221;\u3002\u5982\u679c\u4f60\u7684\u7cfb\u7edf\u914d\u7f6e\u9002\u5f53\u4e14\u672c\u5730\u5316\u8bbe\u7f6e\u4e3a\u6cd5\u8bed\uff0c\u90a3\u4e48\u5185\u90e8\u7684 C \u51fd\u6570\u5c06\u544a\u8bc9\u7a0b\u5e8f &#8220;\u00e9&#8221; \u4e5f\u5e94\u8be5\u88ab\u8ba4\u4e3a\u662f\u4e00\u4e2a\u5b57\u6bcd\u3002\u5f53\u5728\u7f16\u8bd1\u6b63\u5219\u8868\u8fbe\u5f0f\u65f6\u4f7f\u7528 LOCALE \u6807\u5fd7\u4f1a\u5f97\u5230\u7528\u8fd9\u4e9b C \u51fd\u6570\u6765\u5904\u7406 \\w \u540e\u7684\u7f16\u8bd1\u5bf9\u8c61\uff1b\u8fd9\u4f1a\u66f4\u6162\uff0c\u4f46\u4e5f\u4f1a\u8c61\u4f60\u5e0c\u671b\u7684\u90a3\u6837\u53ef\u4ee5\u7528 \\w+ \u6765\u5339\u914d\u6cd5\u6587\u6587\u672c\u3002<\/p>\n<p><strong>M<\/strong>\n<strong>MULTILINE<\/strong>\n(\u6b64\u65f6 ^ \u548c $ \u4e0d\u4f1a\u88ab\u89e3\u91ca; \u5b83\u4eec\u5c06\u5728 4.1 \u8282\u88ab\u4ecb\u7ecd.)\n\u4f7f\u7528 &#8220;^&#8221; \u53ea\u5339\u914d\u5b57\u7b26\u4e32\u7684\u5f00\u59cb\uff0c\u800c $ \u5219\u53ea\u5339\u914d\u5b57\u7b26\u4e32\u7684\u7ed3\u5c3e\u548c\u76f4\u63a5\u5728\u6362\u884c\u524d\uff08\u5982\u679c\u6709\u7684\u8bdd\uff09\u7684\u5b57\u7b26\u4e32\u7ed3\u5c3e\u3002\u5f53\u672c\u6807\u5fd7\u6307\u5b9a\u540e\uff0c &#8220;^&#8221; \u5339\u914d\u5b57\u7b26\u4e32\u7684\u5f00\u59cb\u548c\u5b57\u7b26\u4e32\u4e2d\u6bcf\u884c\u7684\u5f00\u59cb\u3002\u540c\u6837\u7684\uff0c $ \u5143\u5b57\u7b26\u5339\u914d\u5b57\u7b26\u4e32\u7ed3\u5c3e\u548c\u5b57\u7b26\u4e32\u4e2d\u6bcf\u884c\u7684\u7ed3\u5c3e\uff08\u76f4\u63a5\u5728\u6bcf\u4e2a\u6362\u884c\u4e4b\u524d\uff09\u3002<\/p>\n<p><strong>S<\/strong>\n<strong>DOTALL<\/strong><\/p>\n<p>\u4f7f &#8220;.&#8221; \u7279\u6b8a\u5b57\u7b26\u5b8c\u5168\u5339\u914d\u4efb\u4f55\u5b57\u7b26\uff0c\u5305\u62ec\u6362\u884c\uff1b\u6ca1\u6709\u8fd9\u4e2a\u6807\u5fd7\uff0c &#8220;.&#8221; \u5339\u914d\u9664\u4e86\u6362\u884c\u5916\u7684\u4efb\u4f55\u5b57\u7b26\u3002<\/p>\n<p><strong>X<\/strong>\n<strong>VERBOSE<\/strong>\n\u8be5\u6807\u5fd7\u901a\u8fc7\u7ed9\u4e88\u4f60\u66f4\u7075\u6d3b\u7684\u683c\u5f0f\u4ee5\u4fbf\u4f60\u5c06\u6b63\u5219\u8868\u8fbe\u5f0f\u5199\u5f97\u66f4\u6613\u4e8e\u7406\u89e3\u3002\u5f53\u8be5\u6807\u5fd7\u88ab\u6307\u5b9a\u65f6\uff0c\u5728 RE \u5b57\u7b26\u4e32\u4e2d\u7684\u7a7a\u767d\u7b26\u88ab\u5ffd\u7565\uff0c\u9664\u975e\u8be5\u7a7a\u767d\u7b26\u5728\u5b57\u7b26\u7c7b\u4e2d\u6216\u5728\u53cd\u659c\u6760\u4e4b\u540e\uff1b\u8fd9\u53ef\u4ee5\u8ba9\u4f60\u66f4\u6e05\u6670\u5730\u7ec4\u7ec7\u548c\u7f29\u8fdb RE\u3002\u5b83\u4e5f\u53ef\u4ee5\u5141\u8bb8\u4f60\u5c06\u6ce8\u91ca\u5199\u5165 RE\uff0c\u8fd9\u4e9b\u6ce8\u91ca\u4f1a\u88ab\u5f15\u64ce\u5ffd\u7565\uff1b\u6ce8\u91ca\u7528 &#8220;#&#8221;\u53f7 \u6765\u6807\u8bc6\uff0c\u4e0d\u8fc7\u8be5\u7b26\u53f7\u4e0d\u80fd\u5728\u5b57\u7b26\u4e32\u6216\u53cd\u659c\u6760\u4e4b\u540e\u3002\n\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u8fd9\u91cc\u6709\u4e00\u4e2a\u4f7f\u7528 re.VERBOSE \u7684 RE\uff1b\u770b\u770b\u8bfb\u5b83\u8f7b\u677e\u4e86\u591a\u5c11\uff1f<\/p>\n<pre>#!python\ncharref = re.compile(r\"\"\"&[[]]         # Start of a numeric entity reference|||here has wrong.i can't fix\n(\n[0-9]+[^0-9]      # Decimal form\n| 0[0-7]+[^0-7]   # Octal form\n| x[0-9a-fA-F]+[^0-9a-fA-F] # Hexadecimal form\n)\n\"\"\", re.VERBOSE)<\/pre>\n<p>\u6ca1\u6709 verbose \u8bbe\u7f6e\uff0c RE \u4f1a\u770b\u8d77\u6765\u8c61\u8fd9\u6837\uff1a<\/p>\n<pre>#!python\ncharref = re.compile(\"&#([0-9]+[^0-9]\"\n\"|0[0-7]+[^0-7]\"\n\"|x[0-9a-fA-F]+[^0-9a-fA-F])\")<\/pre>\n<p>\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u91cc\uff0cPython \u7684\u5b57\u7b26\u4e32\u81ea\u52a8\u8fde\u63a5\u53ef\u4ee5\u7528\u6765\u5c06 RE \u5206\u6210\u66f4\u5c0f\u7684\u90e8\u5206\uff0c\u4f46\u5b83\u6bd4\u7528 re.VERBOSE \u6807\u5fd7\u65f6\u66f4\u96be\u61c2<\/p>\n<p><a id=\".E6.9B.B4.E5.A4.9A.E6.A8.A1.E5.BC.8F.E5.8A.9F.E8.83.BD\" name=\".E6.9B.B4.E5.A4.9A.E6.A8.A1.E5.BC.8F.E5.8A.9F.E8.83.BD\"><\/a><\/p>\n<h3>\u66f4\u591a\u6a21\u5f0f\u529f\u80fd<\/h3>\n<p>\u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u6211\u4eec\u53ea\u5c55\u793a\u4e86\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u4e00\u90e8\u5206\u529f\u80fd\u3002\u5728\u672c\u8282\uff0c\u6211\u4eec\u5c06\u5c55\u793a\u4e00\u4e9b\u65b0\u7684\u5143\u5b57\u7b26\u548c\u5982\u4f55\u4f7f\u7528\u7ec4\u6765\u68c0\u7d22\u88ab\u5339\u914d\u7684\u6587\u672c\u90e8\u5206\u3002 ddddddddddddddddddddddddddddd<\/p>\n<p>== ==<\/p>\n<p><a id=\".E6.9B.B4.E5.A4.9A.E7.9A.84.E5.85.83.E5.AD.97.E7.AC.A6\" name=\".E6.9B.B4.E5.A4.9A.E7.9A.84.E5.85.83.E5.AD.97.E7.AC.A6\"><\/a><\/p>\n<h4>\u00a0\u66f4\u591a\u7684\u5143\u5b57\u7b26<\/h4>\n<p><strong>\u7c97\u4f53\u6587\u5b57<\/strong>\n<a title=\"http:\/\/www.example.com\" href=\"http:\/\/www.example.com\/\" rel=\"nofollow\">\u94fe\u63a5\u6807\u9898<\/a>\u8fd8\u6709\u4e00\u4e9b\u6211\u4eec\u8fd8\u6ca1\u5c55\u793a\u7684\u5143\u5b57\u7b26\uff0c\u5176\u4e2d\u7684\u5927\u90e8\u5206\u5c06\u5728\u672c\u8282\u5c55\u793a\u3002\n\u5269\u4e0b\u6765\u8981\u8ba8\u8bba\u7684\u4e00\u90e8\u5206\u5143\u5b57\u7b26\u662f\u96f6\u5bbd\u754c\u5b9a\u7b26\uff08zero-width assertions\uff09\u3002\u5b83\u4eec\u5e76\u4e0d\u4f1a\u4f7f\u5f15\u64ce\u5728\u5904\u7406\u5b57\u7b26\u4e32\u65f6\u66f4\u5feb;\u76f8\u53cd\uff0c\u5b83\u4eec\u6839\u672c\u5c31\u6ca1\u6709\u5bf9\u5e94\u4efb\u4f55\u5b57\u7b26\uff0c\u53ea\u662f\u7b80\u5355\u7684\u6210\u529f\u6216\u5931\u8d25\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0c \\b \u662f\u4e00\u4e2a\u5728\u5355\u8bcd\u8fb9\u754c\u5b9a\u4f4d\u5f53\u524d\u4f4d\u7f6e\u7684\u754c\u5b9a\u7b26\uff08assertions\uff09\uff0c\u8fd9\u4e2a\u4f4d\u7f6e\u6839\u672c\u5c31\u4e0d\u4f1a\u88ab \\b \u6539\u53d8\u3002\u8fd9\u610f\u5473\u7740\u96f6\u5bbd\u754c\u5b9a\u7b26\uff08zero-width assertions\uff09\u5c06\u6c38\u8fdc\u4e0d\u4f1a\u88ab\u91cd\u590d\uff0c\u56e0\u4e3a\u5982\u679c\u5b83\u4eec\u5728\u7ed9\u5b9a\u4f4d\u7f6e\u5339\u914d\u4e00\u6b21\uff0c\u90a3\u4e48\u5b83\u4eec\u5f88\u660e\u663e\u53ef\u4ee5\u88ab\u5339\u914d\u65e0\u6570\u6b21\u3002<\/p>\n<p><strong>|<\/strong>\n\u53ef\u9009\u9879\uff0c\u6216\u8005 &#8220;or&#8221; \u64cd\u4f5c\u7b26\u3002\u5982\u679c A \u548c B \u662f\u6b63\u5219\u8868\u8fbe\u5f0f\uff0cA|B \u5c06\u5339\u914d\u4efb\u4f55\u5339\u914d\u4e86 &#8220;A&#8221; \u6216 &#8220;B&#8221; \u7684\u5b57\u7b26\u4e32\u3002| \u7684\u4f18\u5148\u7ea7\u975e\u5e38\u4f4e\uff0c\u662f\u4e3a\u4e86\u5f53\u4f60\u6709\u591a\u5b57\u7b26\u4e32\u8981\u9009\u62e9\u65f6\u80fd\u9002\u5f53\u5730\u8fd0\u884c\u3002Crow|Servo \u5c06\u5339\u914d&#8221;Crow&#8221; \u6216 &#8220;Servo&#8221;, \u800c\u4e0d\u662f &#8220;Cro&#8221;, \u4e00\u4e2a &#8220;w&#8221; \u6216 \u4e00\u4e2a &#8220;S&#8221;, \u548c &#8220;ervo&#8221;\u3002\n\u4e3a\u4e86\u5339\u914d\u5b57\u6bcd &#8220;|&#8221;\uff0c\u53ef\u4ee5\u7528 |\uff0c\u6216\u5c06\u5176\u5305\u542b\u5728\u5b57\u7b26\u7c7b\u4e2d\uff0c\u5982[|]\u3002<\/p>\n<p><strong>^<\/strong>\n\u5339\u914d\u884c\u9996\u3002\u9664\u975e\u8bbe\u7f6e MULTILINE \u6807\u5fd7\uff0c\u5b83\u53ea\u662f\u5339\u914d\u5b57\u7b26\u4e32\u7684\u5f00\u59cb\u3002\u5728 MULTILINE \u6a21\u5f0f\u91cc\uff0c\u5b83\u4e5f\u53ef\u4ee5\u76f4\u63a5\u5339\u914d\u5b57\u7b26\u4e32\u4e2d\u7684\u6bcf\u4e2a\u6362\u884c\u3002\n\u4f8b\u5982\uff0c\u5982\u679c\u4f60\u53ea\u5e0c\u671b\u5339\u914d\u5728\u884c\u9996\u5355\u8bcd &#8220;From&#8221;\uff0c\u90a3\u4e48 RE \u5c06\u7528 ^From\u3002<\/p>\n<pre>#!python\n>>> print re.search('^From', 'From Here to Eternity')\n<re.MatchObject instance at 80c1520>\n>>> print re.search('^From', 'Reciting From Memory')\nNone<\/pre>\n<p><strong>$<\/strong>\n\u5339\u914d\u884c\u5c3e\uff0c\u884c\u5c3e\u88ab\u5b9a\u4e49\u4e3a\u8981\u4e48\u662f\u5b57\u7b26\u4e32\u5c3e\uff0c\u8981\u4e48\u662f\u4e00\u4e2a\u6362\u884c\u5b57\u7b26\u540e\u9762\u7684\u4efb\u4f55\u4f4d\u7f6e\u3002<\/p>\n<pre>#!python\n>>> print re.search('}$', '{block}')\n<re.MatchObject instance at 80adfa8>\n>>> print re.search('}$', '{block} ')\nNone\n>>> print re.search('}$', '{block}\\n')\n<re.MatchObject instance at 80adfa8><\/pre>\n<p>\u5339\u914d\u4e00\u4e2a &#8220;$&#8221;\uff0c\u4f7f\u7528 \\$ \u6216\u5c06\u5176\u5305\u542b\u5728\u5b57\u7b26\u7c7b\u4e2d\uff0c\u5982[$]\u3002<\/p>\n<p><strong>\\A<\/strong>\n\u53ea\u5339\u914d\u5b57\u7b26\u4e32\u9996\u3002\u5f53\u4e0d\u5728 MULTILINE \u6a21\u5f0f\uff0c\\A \u548c ^ \u5b9e\u9645\u4e0a\u662f\u4e00\u6837\u7684\u3002\u7136\u800c\uff0c\u5728 MULTILINE \u6a21\u5f0f\u91cc\u5b83\u4eec\u662f\u4e0d\u540c\u7684\uff1b\\A \u53ea\u662f\u5339\u914d\u5b57\u7b26\u4e32\u9996\uff0c\u800c ^ \u8fd8\u53ef\u4ee5\u5339\u914d\u5728\u6362\u884c\u7b26\u4e4b\u540e\u5b57\u7b26\u4e32\u7684\u4efb\u4f55\u4f4d\u7f6e\u3002<\/p>\n<p><strong>\\Z<\/strong><\/p>\n<p>Matches only at the end of the string.\n\u53ea\u5339\u914d\u5b57\u7b26\u4e32\u5c3e\u3002<\/p>\n<p><strong>\\b<\/strong><\/p>\n<p>\u5355\u8bcd\u8fb9\u754c\u3002\u8fd9\u662f\u4e2a\u96f6\u5bbd\u754c\u5b9a\u7b26\uff08zero-width assertions\uff09\u53ea\u7528\u4ee5\u5339\u914d\u5355\u8bcd\u7684\u8bcd\u9996\u548c\u8bcd\u5c3e\u3002\u5355\u8bcd\u88ab\u5b9a\u4e49\u4e3a\u4e00\u4e2a\u5b57\u6bcd\u6570\u5b57\u5e8f\u5217\uff0c\u56e0\u6b64\u8bcd\u5c3e\u5c31\u662f\u7528\u7a7a\u767d\u7b26\u6216\u975e\u5b57\u6bcd\u6570\u5b57\u7b26\u6765\u6807\u793a\u7684\u3002\n\u4e0b\u9762\u7684\u4f8b\u5b50\u53ea\u5339\u914d &#8220;class&#8221; \u6574\u4e2a\u5355\u8bcd\uff1b\u800c\u5f53\u5b83\u88ab\u5305\u542b\u5728\u5176\u4ed6\u5355\u8bcd\u4e2d\u65f6\u4e0d\u5339\u914d\u3002<\/p>\n<pre>#!python\n>>> p = re.compile(r'\\bclass\\b')\n>>> print p.search('no class at all')\n<re.MatchObject instance at 80c8f28>\n>>> print p.search('the declassified algorithm')\nNone\n>>> print p.search('one subclass is')\nNone<\/pre>\n<p>\u5f53\u7528\u8fd9\u4e2a\u7279\u6b8a\u5e8f\u5217\u65f6\u4f60\u5e94\u8be5\u8bb0\u4f4f\u8fd9\u91cc\u6709\u4e24\u4e2a\u5fae\u5999\u4e4b\u5904\u3002\u7b2c\u4e00\u4e2a\u662f Python \u5b57\u7b26\u4e32\u548c\u6b63\u5219\u8868\u8fbe\u5f0f\u4e4b\u95f4\u6700\u7cdf\u7684\u51b2\u7a81\u3002\u5728 Python \u5b57\u7b26\u4e32\u91cc\uff0c&#8221;\\b&#8221; \u662f\u53cd\u659c\u6760\u5b57\u7b26\uff0cASCII\u503c\u662f8\u3002\u5982\u679c\u4f60\u6ca1\u6709\u4f7f\u7528 raw \u5b57\u7b26\u4e32\u65f6\uff0c\u90a3\u4e48 Python \u5c06\u4f1a\u628a &#8220;\\b&#8221; \u8f6c\u6362\u6210\u4e00\u4e2a\u56de\u9000\u7b26\uff0c\u4f60\u7684 RE \u5c06\u65e0\u6cd5\u8c61\u4f60\u5e0c\u671b\u7684\u90a3\u6837\u5339\u914d\u5b83\u4e86\u3002\u4e0b\u9762\u7684\u4f8b\u5b50\u770b\u8d77\u6765\u548c\u6211\u4eec\u524d\u9762\u7684 RE \u4e00\u6837\uff0c\u4f46\u5728 RE \u5b57\u7b26\u4e32\u524d\u5c11\u4e86\u4e00\u4e2a &#8220;r&#8221; \u3002<\/p>\n<pre>#!python\n>>> p = re.compile('\\bclass\\b')\n>>> print p.search('no class at all')\nNone\n>>> print p.search('\\b' + 'class' + '\\b')\n<re.MatchObject instance at 80c3ee0><\/pre>\n<p>\u7b2c\u4e8c\u4e2a\u5728\u5b57\u7b26\u7c7b\u4e2d\uff0c\u8fd9\u4e2a\u9650\u5b9a\u7b26\uff08assertion\uff09\u4e0d\u8d77\u4f5c\u7528\uff0c\\b \u8868\u793a\u56de\u9000\u7b26\uff0c\u4ee5\u4fbf\u4e0e Python \u5b57\u7b26\u4e32\u517c\u5bb9\u3002<\/p>\n<p><strong>\\B<\/strong>\n\u53e6\u4e00\u4e2a\u96f6\u5bbd\u754c\u5b9a\u7b26\uff08zero-width assertions\uff09\uff0c\u5b83\u6b63\u597d\u540c \\b \u76f8\u53cd\uff0c\u53ea\u5728\u5f53\u524d\u4f4d\u7f6e\u4e0d\u5728\u5355\u8bcd\u8fb9\u754c\u65f6\u5339\u914d\u3002<\/p>\n<p><a id=\".E5.88.86.E7.BB.84\" name=\".E5.88.86.E7.BB.84\"><\/a><\/p>\n<h4>\u5206\u7ec4<\/h4>\n<p>\u4f60\u7ecf\u5e38\u9700\u8981\u5f97\u5230\u6bd4 RE \u662f\u5426\u5339\u914d\u8fd8\u8981\u591a\u7684\u4fe1\u606f\u3002\u6b63\u5219\u8868\u8fbe\u5f0f\u5e38\u5e38\u7528\u6765\u5206\u6790\u5b57\u7b26\u4e32\uff0c\u7f16\u5199\u4e00\u4e2a RE \u5339\u914d\u611f\u5174\u8da3\u7684\u90e8\u5206\u5e76\u5c06\u5176\u5206\u6210\u51e0\u4e2a\u5c0f\u7ec4\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u4e00\u4e2a RFC-822 \u7684\u5934\u90e8\u7528 &#8220;:&#8221; \u9694\u6210\u4e00\u4e2a\u5934\u90e8\u540d\u548c\u4e00\u4e2a\u503c\uff0c\u8fd9\u5c31\u53ef\u4ee5\u901a\u8fc7\u7f16\u5199\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u5339\u914d\u6574\u4e2a\u5934\u90e8\uff0c\u7528\u4e00\u7ec4\u5339\u914d\u5934\u90e8\u540d\uff0c\u53e6\u4e00\u7ec4\u5339\u914d\u5934\u90e8\u503c\u7684\u65b9\u5f0f\u6765\u5904\u7406\u3002\n\u7ec4\u662f\u901a\u8fc7 &#8220;(&#8221; \u548c &#8220;)&#8221; \u5143\u5b57\u7b26\u6765\u6807\u8bc6\u7684\u3002 &#8220;(&#8221; \u548c &#8220;)&#8221; \u6709\u5f88\u591a\u5728\u6570\u5b66\u8868\u8fbe\u5f0f\u4e2d\u76f8\u540c\u7684\u610f\u601d\uff1b\u5b83\u4eec\u4e00\u8d77\u628a\u5728\u5b83\u4eec\u91cc\u9762\u7684\u8868\u8fbe\u5f0f\u7ec4\u6210\u4e00\u7ec4\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u4f60\u53ef\u4ee5\u7528\u91cd\u590d\u9650\u5236\u7b26\uff0c\u8c61 <em>, +,\u00a0?, \u548c {m,n}\uff0c\u6765\u91cd\u590d\u7ec4\u91cc\u7684\u5185\u5bb9\uff0c\u6bd4\u5982\u8bf4(ab)<\/em> \u5c06\u5339\u914d\u96f6\u6216\u66f4\u591a\u4e2a\u91cd\u590d\u7684 &#8220;ab&#8221;\u3002<\/p>\n<pre>#!python\n>>> p = re.compile('(ab)*')\n>>> print p.match('ababababab').span()\n(0, 10)<\/pre>\n<p>\u7ec4\u7528 &#8220;(&#8221; \u548c &#8220;)&#8221; \u6765\u6307\u5b9a\uff0c\u5e76\u4e14\u5f97\u5230\u5b83\u4eec\u5339\u914d\u6587\u672c\u7684\u5f00\u59cb\u548c\u7ed3\u5c3e\u7d22\u5f15\uff1b\u8fd9\u5c31\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e2a\u53c2\u6570\u7528 group()\u3001start()\u3001end() \u548c span() \u6765\u8fdb\u884c\u68c0\u7d22\u3002\u7ec4\u662f\u4ece 0 \u5f00\u59cb\u8ba1\u6570\u7684\u3002\u7ec4 0 \u603b\u662f\u5b58\u5728\uff1b\u5b83\u5c31\u662f\u6574\u4e2a RE\uff0c\u6240\u4ee5 <code>MatchObject<\/code> \u7684\u65b9\u6cd5\u90fd\u628a\u7ec4 0 \u4f5c\u4e3a\u5b83\u4eec\u7f3a\u7701\u7684\u53c2\u6570\u3002\u7a0d\u540e\u6211\u4eec\u5c06\u770b\u5230\u600e\u6837\u8868\u8fbe\u4e0d\u80fd\u5f97\u5230\u5b83\u4eec\u6240\u5339\u914d\u6587\u672c\u7684 span\u3002<\/p>\n<pre>#!python\n>>> p = re.compile('(a)b')\n>>> m = p.match('ab')\n>>> m.group()\n'ab'\n>>> m.group(0)\n'ab'<\/pre>\n<p>\u5c0f\u7ec4\u662f\u4ece\u5de6\u5411\u53f3\u8ba1\u6570\u7684\uff0c\u4ece1\u5f00\u59cb\u3002\u7ec4\u53ef\u4ee5\u88ab\u5d4c\u5957\u3002\u8ba1\u6570\u7684\u6570\u503c\u53ef\u4ee5\u901a\u8fc7\u4ece\u5de6\u5230\u53f3\u8ba1\u7b97\u6253\u5f00\u7684\u62ec\u53f7\u6570\u6765\u786e\u5b9a\u3002<\/p>\n<pre>#!python\n>>> p = re.compile('(a(b)c)d')\n>>> m = p.match('abcd')\n>>> m.group(0)\n'abcd'\n>>> m.group(1)\n'abc'\n>>> m.group(2)\n'b'<\/pre>\n<p>group() \u53ef\u4ee5\u4e00\u6b21\u8f93\u5165\u591a\u4e2a\u7ec4\u53f7\uff0c\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u5b83\u5c06\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u90a3\u4e9b\u7ec4\u6240\u5bf9\u5e94\u503c\u7684\u5143\u7ec4\u3002<\/p>\n<pre>#!python\n>>> m.group(2,1,2)\n('b', 'abc', 'b')<\/pre>\n<p>The groups() \u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u6240\u6709\u5c0f\u7ec4\u5b57\u7b26\u4e32\u7684\u5143\u7ec4\uff0c\u4ece 1 \u5230 \u6240\u542b\u7684\u5c0f\u7ec4\u53f7\u3002<\/p>\n<pre>#!python\n>>> m.groups()\n('abc', 'b')<\/pre>\n<p>\u6a21\u5f0f\u4e2d\u7684\u9006\u5411\u5f15\u7528\u5141\u8bb8\u4f60\u6307\u5b9a\u5148\u524d\u6355\u83b7\u7ec4\u7684\u5185\u5bb9\uff0c\u8be5\u7ec4\u4e5f\u5fc5\u987b\u5728\u5b57\u7b26\u4e32\u5f53\u524d\u4f4d\u7f6e\u88ab\u627e\u5230\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u5982\u679c\u7ec4 1 \u7684\u5185\u5bb9\u80fd\u591f\u5728\u5f53\u524d\u4f4d\u7f6e\u627e\u5230\u7684\u8bdd\uff0c\\1 \u5c31\u6210\u529f\u5426\u5219\u5931\u8d25\u3002\u8bb0\u4f4f Python \u5b57\u7b26\u4e32\u4e5f\u662f\u7528\u53cd\u659c\u6760\u52a0\u6570\u636e\u6765\u5141\u8bb8\u5b57\u7b26\u4e32\u4e2d\u5305\u542b\u4efb\u610f\u5b57\u7b26\u7684\uff0c\u6240\u4ee5\u5f53\u5728 RE \u4e2d\u4f7f\u7528\u9006\u5411\u5f15\u7528\u65f6\u786e\u4fdd\u4f7f\u7528 raw \u5b57\u7b26\u4e32\u3002\n\u4f8b\u5982\uff0c\u4e0b\u9762\u7684 RE \u5728\u4e00\u4e2a\u5b57\u7b26\u4e32\u4e2d\u627e\u5230\u6210\u53cc\u7684\u8bcd\u3002<\/p>\n<pre>#!python\n>>> p = re.compile(r'(\\b\\w+)\\s+\\1')\n>>> p.search('Paris in the the spring').group()\n'the the'<\/pre>\n<p>\u8c61\u8fd9\u6837\u53ea\u662f\u641c\u7d22\u4e00\u4e2a\u5b57\u7b26\u4e32\u7684\u9006\u5411\u5f15\u7528\u5e76\u4e0d\u5e38\u89c1 &#8212; \u7528\u8fd9\u79cd\u65b9\u5f0f\u91cd\u590d\u6570\u636e\u7684\u6587\u672c\u683c\u5f0f\u5e76\u4e0d\u591a\u89c1 &#8212; \u4f46\u4f60\u4e0d\u4e45\u5c31\u53ef\u4ee5\u53d1\u73b0\u5b83\u4eec\u7528\u5728\u5b57\u7b26\u4e32\u66ff\u6362\u4e0a\u975e\u5e38\u6709\u7528\u3002<\/p>\n<p><a id=\".E6.97.A0.E6.8D.95.E8.8E.B7.E7.BB.84.E5.92.8C.E5.91.BD.E5.90.8D.E7.BB.84\" name=\".E6.97.A0.E6.8D.95.E8.8E.B7.E7.BB.84.E5.92.8C.E5.91.BD.E5.90.8D.E7.BB.84\"><\/a><\/p>\n<h4>\u65e0\u6355\u83b7\u7ec4\u548c\u547d\u540d\u7ec4<\/h4>\n<p>\u7cbe\u5fc3\u8bbe\u8ba1\u7684 REs \u4e5f\u8bb8\u4f1a\u7528\u5f88\u591a\u7ec4\uff0c\u65e2\u53ef\u4ee5\u6355\u83b7\u611f\u5174\u8da3\u7684\u5b50\u4e32\uff0c\u53c8\u53ef\u4ee5\u5206\u7ec4\u548c\u7ed3\u6784\u5316 RE \u672c\u8eab\u3002\u5728\u590d\u6742\u7684 REs \u91cc\uff0c\u8ffd\u8e2a\u7ec4\u53f7\u53d8\u5f97\u56f0\u96be\u3002\u6709\u4e24\u4e2a\u529f\u80fd\u53ef\u4ee5\u5bf9\u8fd9\u4e2a\u95ee\u9898\u6709\u6240\u5e2e\u52a9\u3002\u5b83\u4eec\u4e5f\u90fd\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u6269\u5c55\u7684\u901a\u7528\u8bed\u6cd5\uff0c\u56e0\u6b64\u6211\u4eec\u6765\u770b\u770b\u7b2c\u4e00\u4e2a\u3002\nPerl 5 \u5bf9\u6807\u51c6\u6b63\u5219\u8868\u8fbe\u5f0f\u589e\u52a0\u4e86\u51e0\u4e2a\u9644\u52a0\u529f\u80fd\uff0cPython \u7684 re \u6a21\u5757\u4e5f\u652f\u6301\u5176\u4e2d\u7684\u5927\u90e8\u5206\u3002\u9009\u62e9\u4e00\u4e2a\u65b0\u7684\u5355\u6309\u952e\u5143\u5b57\u7b26\u6216\u4e00\u4e2a\u4ee5 &#8220;\\&#8221; \u5f00\u59cb\u7684\u7279\u6b8a\u5e8f\u5217\u6765\u8868\u793a\u65b0\u7684\u529f\u80fd\uff0c\u800c\u53c8\u4e0d\u4f1a\u4f7f Perl \u6b63\u5219\u8868\u8fbe\u5f0f\u4e0e\u6807\u51c6\u6b63\u5219\u8868\u8fbe\u5f0f\u4ea7\u751f\u6df7\u4e71\u662f\u6709\u96be\u5ea6\u7684\u3002\u5982\u679c\u4f60\u9009\u62e9 &#8220;&#038;&#8221; \u505a\u4e3a\u65b0\u7684\u5143\u5b57\u7b26\uff0c\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u8001\u7684\u8868\u8fbe\u5f0f\u8ba4\u4e3a &#8220;&#038;&#8221; \u662f\u4e00\u4e2a\u6b63\u5e38\u7684\u5b57\u7b26\uff0c\u800c\u4e0d\u4f1a\u5728\u4f7f\u7528 \\&#038; \u6216 [&#038;] \u65f6\u4e5f\u4e0d\u4f1a\u8f6c\u4e49\u3002\nPerl \u5f00\u53d1\u4eba\u5458\u7684\u89e3\u51b3\u65b9\u6cd5\u662f\u4f7f\u7528 (?&#8230;) \u6765\u505a\u4e3a\u6269\u5c55\u8bed\u6cd5\u3002&#8221;?&#8221; \u5728\u62ec\u53f7\u540e\u9762\u4f1a\u76f4\u63a5\u5bfc\u81f4\u4e00\u4e2a\u8bed\u6cd5\u9519\u8bef\uff0c\u56e0\u4e3a &#8220;?&#8221; \u6ca1\u6709\u4efb\u4f55\u5b57\u7b26\u53ef\u4ee5\u91cd\u590d\uff0c\u56e0\u6b64\u5b83\u4e0d\u4f1a\u4ea7\u751f\u4efb\u4f55\u517c\u5bb9\u95ee\u9898\u3002\u7d27\u968f &#8220;?&#8221; \u4e4b\u540e\u7684\u5b57\u7b26\u6307\u51fa\u6269\u5c55\u7684\u7528\u9014\uff0c\u56e0\u6b64 (?=foo)\nPython \u65b0\u589e\u4e86\u4e00\u4e2a\u6269\u5c55\u8bed\u6cd5\u5230 Perl \u6269\u5c55\u8bed\u6cd5\u4e2d\u3002\u5982\u679c\u5728\u95ee\u53f7\u540e\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\u662f &#8220;P&#8221;\uff0c\u4f60\u5c31\u53ef\u4ee5\u77e5\u9053\u5b83\u662f\u9488\u5bf9 Python \u7684\u6269\u5c55\u3002\u76ee\u524d\u6709\u4e24\u4e2a\u8fd9\u6837\u7684\u6269\u5c55: (?P<name>&#8230;) \u5b9a\u4e49\u4e00\u4e2a\u547d\u540d\u7ec4\uff0c(?P=name) \u5219\u662f\u5bf9\u547d\u540d\u7ec4\u7684\u9006\u5411\u5f15\u7528\u3002\u5982\u679c Perl 5 \u7684\u672a\u6765\u7248\u672c\u4f7f\u7528\u4e0d\u540c\u7684\u8bed\u6cd5\u589e\u52a0\u4e86\u76f8\u540c\u7684\u529f\u80fd\uff0c\u90a3\u4e48 re \u6a21\u5757\u4e5f\u5c06\u6539\u53d8\u4ee5\u652f\u6301\u65b0\u7684\u8bed\u6cd5\uff0c\u4e0e\u6b64\u540c\u65f6\u4e3a\u4e86\u517c\u5bb9\u6027\u7684\u76ee\u7684\u800c\u7ee7\u7eed\u4fdd\u6301\u7684 Python \u4e13\u7528\u8bed\u6cd5\u3002\n\u73b0\u5728\u6211\u4eec\u770b\u4e00\u4e0b\u666e\u901a\u7684\u6269\u5c55\u8bed\u6cd5\uff0c\u6211\u4eec\u56de\u8fc7\u5934\u6765\u7b80\u5316\u5728\u590d\u6742 REs \u4e2d\u4f7f\u7528\u7ec4\u8fd0\u884c\u7684\u7279\u6027\u3002\u56e0\u4e3a\u7ec4\u662f\u4ece\u5de6\u5230\u53f3\u7f16\u53f7\u7684\uff0c\u800c\u4e14\u4e00\u4e2a\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u4e5f\u8bb8\u4f1a\u4f7f\u7528\u8bb8\u591a\u7ec4\uff0c\u5b83\u53ef\u4ee5\u4f7f\u8ddf\u8e2a\u5f53\u524d\u7ec4\u53f7\u53d8\u5f97\u56f0\u96be\uff0c\u800c\u4fee\u6539\u5982\u6b64\u590d\u6742\u7684 RE \u662f\u5341\u5206\u9ebb\u70e6\u7684\u3002\u5728\u5f00\u59cb\u65f6\u63d2\u5165\u4e00\u4e2a\u65b0\u7ec4\uff0c\u4f60\u53ef\u4ee5\u6539\u53d8\u5b83\u4e4b\u540e\u7684\u6bcf\u4e2a\u7ec4\u53f7\u3002\n\u9996\u5148\uff0c\u6709\u65f6\u4f60\u60f3\u7528\u4e00\u4e2a\u7ec4\u53bb\u6536\u96c6\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u4e00\u90e8\u5206\uff0c\u4f46\u53c8\u5bf9\u7ec4\u7684\u5185\u5bb9\u4e0d\u611f\u5174\u8da3\u3002\u4f60\u53ef\u4ee5\u7528\u4e00\u4e2a\u65e0\u6355\u83b7\u7ec4: (?:&#8230;) \u6765\u5b9e\u73b0\u8fd9\u9879\u529f\u80fd\uff0c\u8fd9\u6837\u4f60\u53ef\u4ee5\u5728\u62ec\u53f7\u4e2d\u53d1\u9001\u4efb\u4f55\u5176\u4ed6\u6b63\u5219\u8868\u8fbe\u5f0f\u3002<\/p>\n<pre>#!python\n>>> m = re.match(\"([abc])+\", \"abc\")\n>>> m.groups()\n('c',)\n>>> m = re.match(\"(?:[abc])+\", \"abc\")\n>>> m.groups()\n()<\/pre>\n<p>\u9664\u4e86\u6355\u83b7\u5339\u914d\u7ec4\u7684\u5185\u5bb9\u4e4b\u5916\uff0c\u65e0\u6355\u83b7\u7ec4\u4e0e\u6355\u83b7\u7ec4\u8868\u73b0\u5b8c\u5168\u4e00\u6837\uff1b\u4f60\u53ef\u4ee5\u5728\u5176\u4e2d\u653e\u7f6e\u4efb\u4f55\u5b57\u7b26\uff0c\u53ef\u4ee5\u7528\u91cd\u590d\u5143\u5b57\u7b26\u5982 &#8220;*&#8221; \u6765\u91cd\u590d\u5b83\uff0c\u53ef\u4ee5\u5728\u5176\u4ed6\u7ec4\uff08\u65e0\u6355\u83b7\u7ec4\u4e0e\u6355\u83b7\u7ec4\uff09\u4e2d\u5d4c\u5957\u5b83\u3002(?:&#8230;) \u5bf9\u4e8e\u4fee\u6539\u5df2\u6709\u7ec4\u5c24\u5176\u6709\u7528\uff0c\u56e0\u4e3a\u4f60\u53ef\u4ee5\u4e0d\u7528\u6539\u53d8\u6240\u6709\u5176\u4ed6\u7ec4\u53f7\u7684\u60c5\u51b5\u4e0b\u6dfb\u52a0\u4e00\u4e2a\u65b0\u7ec4\u3002\u6355\u83b7\u7ec4\u548c\u65e0\u6355\u83b7\u7ec4\u5728\u641c\u7d22\u6548\u7387\u65b9\u9762\u4e5f\u6ca1\u4ec0\u4e48\u4e0d\u540c\uff0c\u6ca1\u6709\u54ea\u4e00\u4e2a\u6bd4\u53e6\u4e00\u4e2a\u66f4\u5feb\u3002\n\u5176\u6b21\uff0c\u66f4\u91cd\u8981\u548c\u5f3a\u5927\u7684\u662f\u547d\u540d\u7ec4\uff1b\u4e0e\u7528\u6570\u5b57\u6307\u5b9a\u7ec4\u4e0d\u540c\u7684\u662f\uff0c\u5b83\u53ef\u4ee5\u7528\u540d\u5b57\u6765\u6307\u5b9a\u3002\n\u547d\u4ee4\u7ec4\u7684\u8bed\u6cd5\u662f Python \u4e13\u7528\u6269\u5c55\u4e4b\u4e00\uff1a (?P<name>&#8230;)\u3002\u540d\u5b57\u5f88\u660e\u663e\u662f\u7ec4\u7684\u540d\u5b57\u3002\u9664\u4e86\u8be5\u7ec4\u6709\u4e2a\u540d\u5b57\u4e4b\u5916\uff0c\u547d\u540d\u7ec4\u4e5f\u540c\u6355\u83b7\u7ec4\u662f\u76f8\u540c\u7684\u3002<code>MatchObject<\/code> \u7684\u65b9\u6cd5\u5904\u7406\u6355\u83b7\u7ec4\u65f6\u63a5\u53d7\u7684\u8981\u4e48\u662f\u8868\u793a\u7ec4\u53f7\u7684\u6574\u6570\uff0c\u8981\u4e48\u662f\u5305\u542b\u7ec4\u540d\u7684\u5b57\u7b26\u4e32\u3002\u547d\u540d\u7ec4\u4e5f\u53ef\u4ee5\u662f\u6570\u5b57\uff0c\u6240\u4ee5\u4f60\u53ef\u4ee5\u901a\u8fc7\u4e24\u79cd\u65b9\u5f0f\u6765\u5f97\u5230\u4e00\u4e2a\u7ec4\u7684\u4fe1\u606f\uff1a<\/p>\n<pre>#!python\n>>> p = re.compile(r'(?P<word>\\b\\w+\\b)')\n>>> m = p.search( '(((( Lots of punctuation )))' )\n>>> m.group('word')\n'Lots'\n>>> m.group(1)\n'Lots'<\/pre>\n<p>\u547d\u540d\u7ec4\u662f\u4fbf\u4e8e\u4f7f\u7528\u7684\uff0c\u56e0\u4e3a\u5b83\u53ef\u4ee5\u8ba9\u4f60\u4f7f\u7528\u5bb9\u6613\u8bb0\u4f4f\u7684\u540d\u5b57\u6765\u4ee3\u66ff\u4e0d\u5f97\u4e0d\u8bb0\u4f4f\u7684\u6570\u5b57\u3002\u8fd9\u91cc\u6709\u4e00\u4e2a\u6765\u81ea imaplib \u6a21\u5757\u7684 RE \u793a\u4f8b\uff1a<\/p>\n<pre>#!python\nInternalDate = re.compile(r'INTERNALDATE \"'\nr'(?P<day>[ 123][0-9])-(?P<mon>[A-Z][a-z][a-z])-'\n    r'(?P<year>[0-9][0-9][0-9][0-9])'\nr' (?P<hour>[0-9][0-9]):(?P<min>[0-9][0-9]):(?P<sec>[0-9][0-9])'\nr' (?P<zonen>[-+])(?P<zoneh>[0-9][0-9])(?P<zonem>[0-9][0-9])'\nr'\"')<\/pre>\n<p>\u5f88\u660e\u663e\uff0c\u5f97\u5230 m.group(&#8216;zonem&#8217;) \u8981\u6bd4\u8bb0\u4f4f\u5f97\u5230\u7ec4 9 \u8981\u5bb9\u6613\u5f97\u591a\u3002\n\u56e0\u4e3a\u9006\u5411\u5f15\u7528\u7684\u8bed\u6cd5\uff0c\u8c61 (&#8230;)\\1 \u8fd9\u6837\u7684\u8868\u8fbe\u5f0f\u6240\u8868\u793a\u7684\u662f\u7ec4\u53f7\uff0c\u8fd9\u65f6\u7528\u7ec4\u540d\u4ee3\u66ff\u7ec4\u53f7\u81ea\u7136\u4f1a\u6709\u5dee\u522b\u3002\u8fd8\u6709\u4e00\u4e2a Python \u6269\u5c55\uff1a(?P=name) \uff0c\u5b83\u53ef\u4ee5\u4f7f\u53eb name \u7684\u7ec4\u5185\u5bb9\u518d\u6b21\u5728\u5f53\u524d\u4f4d\u7f6e\u53d1\u73b0\u3002\u6b63\u5219\u8868\u8fbe\u5f0f\u4e3a\u4e86\u627e\u5230\u91cd\u590d\u7684\u5355\u8bcd\uff0c(\\b\\w+)\\s+\\1 \u4e5f\u53ef\u4ee5\u88ab\u5199\u6210 (?P<word>\\b\\w+)\\s+(?P=word)\uff1a<\/p>\n<pre>#!python\n>>> p = re.compile(r'(?P<word>\\b\\w+)\\s+(?P=word)')\n>>> p.search('Paris in the the spring').group()\n'the the'<\/pre>\n<p><a id=\".E5.89.8D.E5.90.91.E7.95.8C.E5.AE.9A.E7.AC.A6\" name=\".E5.89.8D.E5.90.91.E7.95.8C.E5.AE.9A.E7.AC.A6\"><\/a><\/p>\n<h4>\u524d\u5411\u754c\u5b9a\u7b26<\/h4>\n<p>\u53e6\u4e00\u4e2a\u96f6\u5bbd\u754c\u5b9a\u7b26\uff08zero-width assertion\uff09\u662f\u524d\u5411\u754c\u5b9a\u7b26\u3002\u524d\u5411\u754c\u5b9a\u7b26\u5305\u62ec\u524d\u5411\u80af\u5b9a\u754c\u5b9a\u7b26\u548c\u524d\u9879\u5426\u5b9a\u754c\u5b9a\u7b26\uff0c\u6240\u4e0b\u6240\u793a\uff1a<\/p>\n<p><strong>(?=&#8230;)<\/strong><\/p>\n<p>\u524d\u5411\u80af\u5b9a\u754c\u5b9a\u7b26\u3002\u5982\u679c\u6240\u542b\u6b63\u5219\u8868\u8fbe\u5f0f\uff0c\u4ee5 &#8230; \u8868\u793a\uff0c\u5728\u5f53\u524d\u4f4d\u7f6e\u6210\u529f\u5339\u914d\u65f6\u6210\u529f\uff0c\u5426\u5219\u5931\u8d25\u3002\u4f46\u4e00\u65e6\u6240\u542b\u8868\u8fbe\u5f0f\u5df2\u7ecf\u5c1d\u8bd5\uff0c\u5339\u914d\u5f15\u64ce\u6839\u672c\u6ca1\u6709\u63d0\u9ad8\uff1b\u6a21\u5f0f\u7684\u5269\u4f59\u90e8\u5206\u8fd8\u8981\u5c1d\u8bd5\u754c\u5b9a\u7b26\u7684\u53f3\u8fb9\u3002<\/p>\n<p><strong>(?!&#8230;)<\/strong><\/p>\n<p>\u524d\u5411\u5426\u5b9a\u754c\u5b9a\u7b26\u3002\u4e0e\u80af\u5b9a\u754c\u5b9a\u7b26\u76f8\u53cd\uff1b\u5f53\u6240\u542b\u8868\u8fbe\u5f0f\u4e0d\u80fd\u5728\u5b57\u7b26\u4e32\u5f53\u524d\u4f4d\u7f6e\u5339\u914d\u65f6\u6210\u529f\n\u901a\u8fc7\u793a\u8303\u5728\u54ea\u524d\u5411\u53ef\u4ee5\u6210\u529f\u6709\u52a9\u4e8e\u5177\u4f53\u5b9e\u73b0\u3002\u8003\u8651\u4e00\u4e2a\u7b80\u5355\u7684\u6a21\u5f0f\u7528\u4e8e\u5339\u914d\u4e00\u4e2a\u6587\u4ef6\u540d\uff0c\u5e76\u5c06\u5176\u901a\u8fc7 &#8220;.&#8221; \u5206\u6210\u57fa\u672c\u540d\u548c\u6269\u5c55\u540d\u4e24\u90e8\u5206\u3002\u5982\u5728 &#8220;news.rc&#8221; \u4e2d\uff0c&#8221;news&#8221; \u662f\u57fa\u672c\u540d\uff0c&#8221;rc&#8221; \u662f\u6587\u4ef6\u7684\u6269\u5c55\u540d\u3002\n\u5339\u914d\u6a21\u5f0f\u975e\u5e38\u7b80\u5355\uff1a<\/p>\n<pre>.*[.].*$<\/pre>\n<p>\u6ce8\u610f &#8220;.&#8221; \u9700\u8981\u7279\u6b8a\u5bf9\u5f85\uff0c\u56e0\u4e3a\u5b83\u662f\u4e00\u4e2a\u5143\u5b57\u7b26\uff1b\u6211\u628a\u5b83\u653e\u5728\u4e00\u4e2a\u5b57\u7b26\u7c7b\u4e2d\u3002\u53e6\u5916\u6ce8\u610f\u540e\u9762\u7684 $; \u6dfb\u52a0\u8fd9\u4e2a\u662f\u4e3a\u4e86\u786e\u4fdd\u5b57\u7b26\u4e32\u6240\u6709\u7684\u5269\u4f59\u90e8\u5206\u5fc5\u987b\u88ab\u5305\u542b\u5728\u6269\u5c55\u540d\u4e2d\u3002\u8fd9\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u5339\u914d &#8220;foo.bar&#8221;\u3001&#8221;autoexec.bat&#8221;\u3001 &#8220;sendmail.cf&#8221; \u548c &#8220;printers.conf&#8221;\u3002\n\u73b0\u5728\uff0c\u8003\u8651\u628a\u95ee\u9898\u53d8\u5f97\u590d\u6742\u70b9\uff1b\u5982\u679c\u4f60\u60f3\u5339\u914d\u7684\u6269\u5c55\u540d\u4e0d\u662f &#8220;bat&#8221; \u7684\u6587\u4ef6\u540d\uff1f\u4e00\u4e9b\u4e0d\u6b63\u786e\u7684\u5c1d\u8bd5\uff1a<\/p>\n<pre>.*[.][^b].*$<\/pre>\n<p>\u4e0a\u9762\u7684\u7b2c\u4e00\u6b21\u53bb\u9664 &#8220;bat&#8221; \u7684\u5c1d\u8bd5\u662f\u8981\u6c42\u6269\u5c55\u540d\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\u4e0d\u662f &#8220;b&#8221;\u3002\u8fd9\u662f\u9519\u8bef\u7684\uff0c\u56e0\u4e3a\u8be5\u6a21\u5f0f\u4e5f\u4e0d\u80fd\u5339\u914d &#8220;foo.bar&#8221;\u3002<\/p>\n<pre>.*[.]([^b]..|.[^a].|..[^t])$<\/pre>\n<p>\u5f53\u4f60\u8bd5\u7740\u4fee\u8865\u7b2c\u4e00\u4e2a\u89e3\u51b3\u65b9\u6cd5\u800c\u8981\u6c42\u5339\u914d\u4e0b\u5217\u60c5\u51b5\u4e4b\u4e00\u65f6\u8868\u8fbe\u5f0f\u66f4\u4e71\u4e86\uff1a\u6269\u5c55\u540d\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\u4e0d\u662f &#8220;b&#8221;; \u7b2c\u4e8c\u4e2a\u5b57\u7b26\u4e0d\u662f &#8220;a&#8221;\uff1b\u6216\u7b2c\u4e09\u4e2a\u5b57\u7b26\u4e0d\u662f &#8220;t&#8221;\u3002\u8fd9\u6837\u53ef\u4ee5\u63a5\u53d7 &#8220;foo.bar&#8221; \u800c\u62d2\u7edd &#8220;autoexec.bat&#8221;\uff0c\u4f46\u8fd9\u8981\u6c42\u53ea\u80fd\u662f\u4e09\u4e2a\u5b57\u7b26\u7684\u6269\u5c55\u540d\u800c\u4e0d\u63a5\u53d7\u4e24\u4e2a\u5b57\u7b26\u7684\u6269\u5c55\u540d\u5982 &#8220;sendmail.cf&#8221;\u3002\u6211\u4eec\u5c06\u5728\u52aa\u529b\u4fee\u8865\u5b83\u65f6\u518d\u6b21\u628a\u8be5\u6a21\u5f0f\u53d8\u5f97\u590d\u6742\u3002<\/p>\n<pre>.*[.]([^b].?.?|.[^a]?.?|..?[^t]?)$<\/pre>\n<p>\u5728\u7b2c\u4e09\u6b21\u5c1d\u8bd5\u4e2d\uff0c\u7b2c\u4e8c\u548c\u7b2c\u4e09\u4e2a\u5b57\u6bcd\u90fd\u53d8\u6210\u53ef\u9009\uff0c\u4e3a\u7684\u662f\u5141\u8bb8\u5339\u914d\u6bd4\u4e09\u4e2a\u5b57\u7b26\u66f4\u77ed\u7684\u6269\u5c55\u540d\uff0c\u5982 &#8220;sendmail.cf&#8221;\u3002\n\u8be5\u6a21\u5f0f\u73b0\u5728\u53d8\u5f97\u975e\u5e38\u590d\u6742\uff0c\u8fd9\u4f7f\u5b83\u5f88\u96be\u8bfb\u61c2\u3002\u66f4\u7cdf\u7684\u662f\uff0c\u5982\u679c\u95ee\u9898\u53d8\u5316\u4e86\uff0c\u4f60\u60f3\u6269\u5c55\u540d\u4e0d\u662f &#8220;bat&#8221; \u548c &#8220;exe&#8221;\uff0c\u8be5\u6a21\u5f0f\u751a\u81f3\u4f1a\u53d8\u5f97\u66f4\u590d\u6742\u548c\u6df7\u4e71\u3002\n\u524d\u5411\u5426\u5b9a\u628a\u6240\u6709\u8fd9\u4e9b\u88c1\u526a\u6210\uff1a<\/p>\n<pre>.*[.](?!bat$).*$<\/pre>\n<p>\u524d\u5411\u7684\u610f\u601d\uff1a\u5982\u679c\u8868\u8fbe\u5f0f bat \u5728\u8fd9\u91cc\u6ca1\u6709\u5339\u914d\uff0c\u5c1d\u8bd5\u6a21\u5f0f\u7684\u5176\u4f59\u90e8\u5206\uff1b\u5982\u679c bat$ \u5339\u914d\uff0c\u6574\u4e2a\u6a21\u5f0f\u5c06\u5931\u8d25\u3002\u540e\u9762\u7684 $ \u88ab\u8981\u6c42\u662f\u4e3a\u4e86\u786e\u4fdd\u8c61 &#8220;sample.batch&#8221; \u8fd9\u6837\u6269\u5c55\u540d\u4ee5 &#8220;bat&#8221; \u5f00\u5934\u7684\u4f1a\u88ab\u5141\u8bb8\u3002\n\u5c06\u53e6\u4e00\u4e2a\u6587\u4ef6\u6269\u5c55\u540d\u6392\u9664\u5728\u5916\u73b0\u5728\u4e5f\u5bb9\u6613\uff1b\u7b80\u5355\u5730\u5c06\u5176\u505a\u4e3a\u53ef\u9009\u9879\u653e\u5728\u754c\u5b9a\u7b26\u4e2d\u3002\u4e0b\u9762\u7684\u8fd9\u4e2a\u6a21\u5f0f\u5c06\u4ee5 &#8220;bat&#8221; \u6216 &#8220;exe&#8221; \u7ed3\u5c3e\u7684\u6587\u4ef6\u540d\u6392\u9664\u5728\u5916\u3002<\/p>\n<pre>.*[.](?!bat$|exe$).*$<\/pre>\n<p><a id=\".E4.BF.AE.E6.94.B9.E5.AD.97.E7.AC.A6.E4.B8.B2\" name=\".E4.BF.AE.E6.94.B9.E5.AD.97.E7.AC.A6.E4.B8.B2\"><\/a><\/p>\n<h3>\u4fee\u6539\u5b57\u7b26\u4e32<\/h3>\n<p>\u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u6211\u4eec\u7b80\u5355\u5730\u641c\u7d22\u4e86\u4e00\u4e2a\u9759\u6001\u5b57\u7b26\u4e32\u3002\u6b63\u5219\u8868\u8fbe\u5f0f\u901a\u5e38\u4e5f\u7528\u4e0d\u540c\u7684\u65b9\u5f0f\uff0c\u901a\u8fc7\u4e0b\u9762\u7684 <code>RegexObject<\/code> \u65b9\u6cd5\uff0c\u6765\u4fee\u6539\u5b57\u7b26\u4e32\u3002<\/p>\n<table border=\"1\" cellspacing=\"0\">\n<tbody>\n<tr>\n<td>\u65b9\u6cd5\/\u5c5e\u6027<\/td>\n<td>\u4f5c\u7528<\/td>\n<\/tr>\n<tr>\n<td>split()<\/td>\n<td>\u5c06\u5b57\u7b26\u4e32\u5728 RE \u5339\u914d\u7684\u5730\u65b9\u5206\u7247\u5e76\u751f\u6210\u4e00\u4e2a\u5217\u8868\uff0c<\/td>\n<\/tr>\n<tr>\n<td>sub()<\/td>\n<td>\u627e\u5230 RE \u5339\u914d\u7684\u6240\u6709\u5b50\u4e32\uff0c\u5e76\u5c06\u5176\u7528\u4e00\u4e2a\u4e0d\u540c\u7684\u5b57\u7b26\u4e32\u66ff\u6362<\/td>\n<\/tr>\n<tr>\n<td>subn()<\/td>\n<td>\u4e0e sub() \u76f8\u540c\uff0c\u4f46\u8fd4\u56de\u65b0\u7684\u5b57\u7b26\u4e32\u548c\u66ff\u6362\u6b21\u6570<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><a id=\".E5.B0.86.E5.AD.97.E7.AC.A6.E4.B8.B2.E5.88.86.E7.89.87\" name=\".E5.B0.86.E5.AD.97.E7.AC.A6.E4.B8.B2.E5.88.86.E7.89.87\"><\/a><\/p>\n<h4>\u5c06\u5b57\u7b26\u4e32\u5206\u7247<\/h4>\n<p><code>RegexObject<\/code> \u7684 split() \u65b9\u6cd5\u5728 RE \u5339\u914d\u7684\u5730\u65b9\u5c06\u5b57\u7b26\u4e32\u5206\u7247\uff0c\u5c06\u8fd4\u56de\u5217\u8868\u3002\u5b83\u540c\u5b57\u7b26\u4e32\u7684 split() \u65b9\u6cd5\u76f8\u4f3c\u4f46\u63d0\u4f9b\u66f4\u591a\u7684\u5b9a\u754c\u7b26\uff1bsplit()\u53ea\u652f\u6301\u7a7a\u767d\u7b26\u548c\u56fa\u5b9a\u5b57\u7b26\u4e32\u3002\u5c31\u8c61\u4f60\u9884\u6599\u7684\u90a3\u6837\uff0c\u4e5f\u6709\u4e00\u4e2a\u6a21\u5757\u7ea7\u7684 re.split() \u51fd\u6570\u3002<\/p>\n<pre>split(string [, maxsplit = 0])<\/pre>\n<p>\u901a\u8fc7\u6b63\u5219\u8868\u8fbe\u5f0f\u5c06\u5b57\u7b26\u4e32\u5206\u7247\u3002\u5982\u679c\u6355\u83b7\u62ec\u53f7\u5728 RE \u4e2d\u4f7f\u7528\uff0c\u90a3\u4e48\u5b83\u4eec\u7684\u5185\u5bb9\u4e5f\u4f1a\u4f5c\u4e3a\u7ed3\u679c\u5217\u8868\u7684\u4e00\u90e8\u5206\u8fd4\u56de\u3002\u5982\u679c maxsplit \u975e\u96f6\uff0c\u90a3\u4e48\u6700\u591a\u53ea\u80fd\u5206\u51fa maxsplit \u4e2a\u5206\u7247\u3002\n\u4f60\u53ef\u4ee5\u901a\u8fc7\u8bbe\u7f6e maxsplit \u503c\u6765\u9650\u5236\u5206\u7247\u6570\u3002\u5f53 maxsplit \u975e\u96f6\u65f6\uff0c\u6700\u591a\u53ea\u80fd\u6709 maxsplit \u4e2a\u5206\u7247\uff0c\u5b57\u7b26\u4e32\u7684\u5176\u4f59\u90e8\u5206\u88ab\u505a\u4e3a\u5217\u8868\u7684\u6700\u540e\u90e8\u5206\u8fd4\u56de\u3002\u5728\u4e0b\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u5b9a\u754c\u7b26\u53ef\u4ee5\u662f\u975e\u6570\u5b57\u5b57\u6bcd\u5b57\u7b26\u7684\u4efb\u610f\u5e8f\u5217\u3002<\/p>\n<pre>#!python\n>>> p = re.compile(r'\\W+')\n>>> p.split('This is a test, short and sweet, of split().')\n['This', 'is', 'a', 'test', 'short', 'and', 'sweet', 'of', 'split', '']\n>>> p.split('This is a test, short and sweet, of split().', 3)\n['This', 'is', 'a', 'test, short and sweet, of split().']<\/pre>\n<p>\u6709\u65f6\uff0c\u4f60\u4e0d\u4ec5\u5bf9\u5b9a\u754c\u7b26\u4e4b\u95f4\u7684\u6587\u672c\u611f\u5174\u8da3\uff0c\u4e5f\u9700\u8981\u77e5\u9053\u5b9a\u754c\u7b26\u662f\u4ec0\u4e48\u3002\u5982\u679c\u6355\u83b7\u62ec\u53f7\u5728 RE \u4e2d\u4f7f\u7528\uff0c\u90a3\u4e48\u5b83\u4eec\u7684\u503c\u4e5f\u4f1a\u5f53\u4f5c\u5217\u8868\u7684\u4e00\u90e8\u5206\u8fd4\u56de\u3002\u6bd4\u8f83\u4e0b\u9762\u7684\u8c03\u7528\uff1a<\/p>\n<pre>#!python\n>>> p = re.compile(r'\\W+')\n>>> p2 = re.compile(r'(\\W+)')\n>>> p.split('This... is a test.')\n['This', 'is', 'a', 'test', '']\n>>> p2.split('This... is a test.')\n['This', '... ', 'is', ' ', 'a', ' ', 'test', '.', '']<\/pre>\n<p>\u6a21\u5757\u7ea7\u51fd\u6570 re.split() \u5c06 RE \u4f5c\u4e3a\u7b2c\u4e00\u4e2a\u53c2\u6570\uff0c\u5176\u4ed6\u4e00\u6837\u3002<\/p>\n<pre>#!python\n>>> re.split('[\\W]+', 'Words, words, words.')\n['Words', 'words', 'words', '']\n>>> re.split('([\\W]+)', 'Words, words, words.')\n['Words', ', ', 'words', ', ', 'words', '.', '']\n>>> re.split('[\\W]+', 'Words, words, words.', 1)\n['Words', 'words, words.']<\/pre>\n<p><a id=\".E6.90.9C.E7.B4.A2.E5.92.8C.E6.9B.BF.E6.8D.A2\" name=\".E6.90.9C.E7.B4.A2.E5.92.8C.E6.9B.BF.E6.8D.A2\"><\/a><\/p>\n<h4>\u641c\u7d22\u548c\u66ff\u6362<\/h4>\n<p>\u5176\u4ed6\u5e38\u89c1\u7684\u7528\u9014\u5c31\u662f\u627e\u5230\u6240\u6709\u6a21\u5f0f\u5339\u914d\u7684\u5b57\u7b26\u4e32\u5e76\u7528\u4e0d\u540c\u7684\u5b57\u7b26\u4e32\u6765\u66ff\u6362\u5b83\u4eec\u3002sub() \u65b9\u6cd5\u63d0\u4f9b\u4e00\u4e2a\u66ff\u6362\u503c\uff0c\u53ef\u4ee5\u662f\u5b57\u7b26\u4e32\u6216\u4e00\u4e2a\u51fd\u6570\uff0c\u548c\u4e00\u4e2a\u8981\u88ab\u5904\u7406\u7684\u5b57\u7b26\u4e32\u3002<\/p>\n<pre>sub(replacement, string[, count = 0])<\/pre>\n<p>\u8fd4\u56de\u7684\u5b57\u7b26\u4e32\u662f\u5728\u5b57\u7b26\u4e32\u4e2d\u7528 RE \u6700\u5de6\u8fb9\u4e0d\u91cd\u590d\u7684\u5339\u914d\u6765\u66ff\u6362\u3002\u5982\u679c\u6a21\u5f0f\u6ca1\u6709\u53d1\u73b0\uff0c\u5b57\u7b26\u5c06\u88ab\u6ca1\u6709\u6539\u53d8\u5730\u8fd4\u56de\u3002\n\u53ef\u9009\u53c2\u6570 count \u662f\u6a21\u5f0f\u5339\u914d\u540e\u66ff\u6362\u7684\u6700\u5927\u6b21\u6570\uff1bcount \u5fc5\u987b\u662f\u975e\u8d1f\u6574\u6570\u3002\u7f3a\u7701\u503c\u662f 0 \u8868\u793a\u66ff\u6362\u6240\u6709\u7684\u5339\u914d\u3002\n\u8fd9\u91cc\u6709\u4e2a\u4f7f\u7528 sub() \u65b9\u6cd5\u7684\u7b80\u5355\u4f8b\u5b50\u3002\u5b83\u7528\u5355\u8bcd &#8220;colour&#8221; \u66ff\u6362\u989c\u8272\u540d\u3002<\/p>\n<pre>#!python\n>>> p = re.compile( '(blue|white|red)')\n>>> p.sub( 'colour', 'blue socks and red shoes')\n'colour socks and colour shoes'\n>>> p.sub( 'colour', 'blue socks and red shoes', count=1)\n'colour socks and red shoes'<\/pre>\n<p>subn() \u65b9\u6cd5\u4f5c\u7528\u4e00\u6837\uff0c\u4f46\u8fd4\u56de\u7684\u662f\u5305\u542b\u65b0\u5b57\u7b26\u4e32\u548c\u66ff\u6362\u6267\u884c\u6b21\u6570\u7684\u4e24\u5143\u7ec4\u3002<\/p>\n<pre>#!python\n>>> p = re.compile( '(blue|white|red)')\n>>> p.subn( 'colour', 'blue socks and red shoes')\n('colour socks and colour shoes', 2)\n>>> p.subn( 'colour', 'no colours at all')\n('no colours at all', 0)<\/pre>\n<p>\u7a7a\u5339\u914d\u53ea\u6709\u5728\u5b83\u4eec\u6ca1\u6709\u7d27\u6328\u7740\u524d\u4e00\u4e2a\u5339\u914d\u65f6\u624d\u4f1a\u88ab\u66ff\u6362\u6389\u3002<\/p>\n<pre>#!python\n>>> p = re.compile('x*')\n>>> p.sub('-', 'abxd')\n'-a-b-d-'<\/pre>\n<p>\u5982\u679c\u66ff\u6362\u7684\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u4efb\u4f55\u5728\u5176\u4e2d\u7684\u53cd\u659c\u6760\u90fd\u4f1a\u88ab\u5904\u7406\u3002&#8221;\\n&#8221; \u5c06\u4f1a\u88ab\u8f6c\u6362\u6210\u4e00\u4e2a\u6362\u884c\u7b26\uff0c&#8221;\\r&#8221;\u8f6c\u6362\u6210\u56de\u8f66\u7b49\u7b49\u3002\u672a\u77e5\u7684\u8f6c\u4e49\u5982 &#8220;\\j&#8221; \u5219\u4fdd\u6301\u539f\u6837\u3002\u9006\u5411\u5f15\u7528\uff0c\u5982 &#8220;\\6&#8243;\uff0c\u88ab RE \u4e2d\u76f8\u5e94\u7684\u7ec4\u5339\u914d\u800c\u88ab\u5b50\u4e32\u66ff\u6362\u3002\u8fd9\u4f7f\u4f60\u53ef\u4ee5\u5728\u66ff\u6362\u540e\u7684\u5b57\u7b26\u4e32\u4e2d\u63d2\u5165\u539f\u59cb\u6587\u672c\u7684\u4e00\u90e8\u5206\u3002\n\u8fd9\u4e2a\u4f8b\u5b50\u5339\u914d\u88ab &#8220;{&#8221; \u548c &#8220;}&#8221; \u62ec\u8d77\u6765\u7684\u5355\u8bcd &#8220;section&#8221;\uff0c\u5e76\u5c06 &#8220;section&#8221; \u66ff\u6362\u6210 &#8220;subsection&#8221;\u3002<\/p>\n<pre>#!python\n>>> p = re.compile('section{ ( [^}]* ) }', re.VERBOSE)\n>>> p.sub(r'subsection{\\1}','section{First} section{second}')\n'subsection{First} subsection{second}'<\/pre>\n<p>\u8fd8\u53ef\u4ee5\u6307\u5b9a\u7528 (?P<name>&#8230;) \u8bed\u6cd5\u5b9a\u4e49\u7684\u547d\u540d\u7ec4\u3002&#8221;\\g<name>&#8221; \u5c06\u901a\u8fc7\u7ec4\u540d &#8220;name&#8221; \u7528\u5b50\u4e32\u6765\u5339\u914d\uff0c\u5e76\u4e14 &#8220;\\g<number>&#8221; \u4f7f\u7528\u76f8\u5e94\u7684\u7ec4\u53f7\u3002\u6240\u4ee5 &#8220;\\g<2>&#8221; \u7b49\u4e8e &#8220;\\2&#8243;\uff0c\u4f46\u80fd\u5728\u66ff\u6362\u5b57\u7b26\u4e32\u91cc\u542b\u4e49\u4e0d\u6e05\uff0c\u5982 &#8220;\\g<2>0&#8243;\u3002\uff08&#8221;\\20&#8243; \u88ab\u89e3\u91ca\u6210\u5bf9\u7ec4 20 \u7684\u5f15\u7528\uff0c\u800c\u4e0d\u662f\u5bf9\u540e\u9762\u8ddf\u7740\u4e00\u4e2a\u5b57\u6bcd &#8220;0&#8221; \u7684\u7ec4 2 \u7684\u5f15\u7528\u3002\uff09<\/p>\n<pre>#!python\n>>> p = re.compile('section{ (?P<name> [^}]* ) }', re.VERBOSE)\n>>> p.sub(r'subsection{\\1}','section{First}')\n'subsection{First}'\n>>> p.sub(r'subsection{\\g<1>}','section{First}')\n'subsection{First}'\n>>> p.sub(r'subsection{\\g<name>}','section{First}')\n'subsection{First}'<\/pre>\n<p>\u66ff\u6362\u4e5f\u53ef\u4ee5\u662f\u4e00\u4e2a\u751a\u81f3\u7ed9\u4f60\u66f4\u591a\u63a7\u5236\u7684\u51fd\u6570\u3002\u5982\u679c\u66ff\u6362\u662f\u4e2a\u51fd\u6570\uff0c\u8be5\u51fd\u6570\u5c06\u4f1a\u88ab\u6a21\u5f0f\u4e2d\u6bcf\u4e00\u4e2a\u4e0d\u91cd\u590d\u7684\u5339\u914d\u6240\u8c03\u7528\u3002\u5728\u6bcf\u6b21\u8c03\u7528\u65f6\uff0c\u51fd\u6570\u4f1a\u88ab\u4f20\u5165\u4e00\u4e2a <code>MatchObject<\/code> \u7684\u5bf9\u8c61\u4f5c\u4e3a\u53c2\u6570\uff0c\u56e0\u6b64\u53ef\u4ee5\u7528\u8fd9\u4e2a\u5bf9\u8c61\u53bb\u8ba1\u7b97\u51fa\u66ff\u6362\u5b57\u7b26\u4e32\u5e76\u8fd4\u56de\u5b83\u3002\n\u5728\u4e0b\u9762\u7684\u4f8b\u5b50\u91cc\uff0c\u66ff\u6362\u51fd\u6570\u5c06\u5341\u8fdb\u5236\u7ffb\u8bd1\u6210\u5341\u516d\u8fdb\u5236\uff1a<\/p>\n<pre>#!python\n>>> def hexrepl( match ):\n...     \"Return the hex string for a decimal number\"\n...     value = int( match.group() )\n...     return hex(value)\n...\n>>> p = re.compile(r'\\d+')\n>>> p.sub(hexrepl, 'Call 65490 for printing, 49152 for user code.')\n'Call 0xffd2 for printing, 0xc000 for user code.'<\/pre>\n<p>\u5f53\u4f7f\u7528\u6a21\u5757\u7ea7\u7684 re.sub() \u51fd\u6570\u65f6\uff0c\u6a21\u5f0f\u4f5c\u4e3a\u7b2c\u4e00\u4e2a\u53c2\u6570\u3002\u6a21\u5f0f\u4e5f\u8bb8\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32\u6216\u4e00\u4e2a <code>RegexObject<\/code>\uff1b\u5982\u679c\u4f60\u9700\u8981\u6307\u5b9a\u6b63\u5219\u8868\u8fbe\u5f0f\u6807\u5fd7\uff0c\u4f60\u5fc5\u987b\u8981\u4e48\u4f7f\u7528 <code>RegexObject<\/code> \u505a\u7b2c\u4e00\u4e2a\u53c2\u6570\uff0c\u6216\u7528\u4f7f\u7528\u6a21\u5f0f\u5185\u5d4c\u4fee\u6b63\u5668\uff0c\u5982 sub(&#8220;(?i)b+&#8221;, &#8220;x&#8221;, &#8220;bbbb BBBB&#8221;) returns &#8216;x x&#8217;\u3002<\/p>\n<p><a id=\".E5.B8.B8.E8.A7.81.E9.97.AE.E9.A2.98\" name=\".E5.B8.B8.E8.A7.81.E9.97.AE.E9.A2.98\"><\/a><\/p>\n<h3>\u5e38\u89c1\u95ee\u9898<\/h3>\n<p>\u6b63\u5219\u8868\u8fbe\u5f0f\u5bf9\u4e00\u4e9b\u5e94\u7528\u7a0b\u5e8f\u6765\u8bf4\u662f\u4e00\u4e2a\u5f3a\u5927\u7684\u5de5\u5177\uff0c\u4f46\u5728\u6709\u4e9b\u65f6\u5019\u5b83\u5e76\u4e0d\u76f4\u89c2\u800c\u4e14\u6709\u65f6\u5b83\u4eec\u4e0d\u6309\u4f60\u671f\u671b\u7684\u8fd0\u884c\u3002\u672c\u8282\u5c06\u6307\u51fa\u4e00\u4e9b\u6700\u5bb9\u6613\u72af\u7684\u5e38\u89c1\u9519\u8bef\u3002<\/p>\n<p><a id=\".E4.BD.BF.E7.94.A8.E5.AD.97.E7.AC.A6.E4.B8.B2.E6.96.B9.E5.BC.8F\" name=\".E4.BD.BF.E7.94.A8.E5.AD.97.E7.AC.A6.E4.B8.B2.E6.96.B9.E5.BC.8F\"><\/a><\/p>\n<h4>\u4f7f\u7528\u5b57\u7b26\u4e32\u65b9\u5f0f<\/h4>\n<p>\u6709\u65f6\u4f7f\u7528 re \u6a21\u5757\u662f\u4e2a\u9519\u8bef\u3002\u5982\u679c\u4f60\u5339\u914d\u4e00\u4e2a\u56fa\u5b9a\u7684\u5b57\u7b26\u4e32\u6216\u5355\u4e2a\u7684\u5b57\u7b26\u7c7b\uff0c\u5e76\u4e14\u4f60\u6ca1\u6709\u4f7f\u7528 re \u7684\u4efb\u4f55\u8c61 IGNORECASE \u6807\u5fd7\u7684\u529f\u80fd\uff0c\u90a3\u4e48\u5c31\u6ca1\u6709\u5fc5\u8981\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u4e86\u3002\u5b57\u7b26\u4e32\u6709\u4e00\u4e9b\u65b9\u6cd5\u662f\u5bf9\u56fa\u5b9a\u5b57\u7b26\u4e32\u8fdb\u884c\u64cd\u4f5c\u7684\uff0c\u5b83\u4eec\u901a\u5e38\u5feb\u5f88\u591a\uff0c\u56e0\u4e3a\u5b83\u4eec\u90fd\u662f\u4e00\u4e2a\u4e2a\u7ecf\u8fc7\u4f18\u5316\u7684 C \u5c0f\u5faa\u73af\uff0c\u7528\u4ee5\u4ee3\u66ff\u5927\u7684\u3001\u66f4\u5177\u901a\u7528\u6027\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u5f15\u64ce\u3002\n\u4e3e\u4e2a \u7528\u4e00\u4e2a\u56fa\u5b9a\u5b57\u7b26\u4e32\u66ff\u6362\u53e6\u4e00\u4e2a \u7684\u4f8b\u5b50\uff0c\u5982\uff1a\u4f60\u53ef\u4ee5\u628a &#8220;deed&#8221; \u66ff\u6362\u6210 &#8220;word&#8221;\u3002re.sub() \u4f3c\u4e4e\u6b63\u662f\u80dc\u4efb\u8fd9\u4e2a\u5de5\u4f5c\u7684\u51fd\u6570\uff0c\u4f46\u8fd8\u662f\u8003\u8651\u8003\u8651 replace() \u65b9\u6cd5\u5427\u3002\u6ce8\u610f replace() \u4e5f\u53ef\u4ee5\u5728\u5355\u8bcd\u91cc\u9762\u8fdb\u884c\u66ff\u6362\uff0c\u53ef\u4ee5\u628a &#8220;swordfish&#8221; \u53d8\u6210 &#8220;sdeedfish&#8221;\u3002\u4e0d\u8fc7 RE \u4e5f\u662f\u53ef\u4ee5\u505a\u5230\u7684\u3002\uff08\u4e3a\u4e86\u907f\u514d\u66ff\u6362\u5355\u8bcd\u7684\u4e00\u90e8\u5206\uff0c\u6a21\u5f0f\u5c06\u5199\u6210 \\bword\\b\uff0c\u8fd9\u662f\u4e3a\u4e86\u8981\u6c42 &#8220;word&#8221; \u4e24\u8fb9\u6709\u4e00\u4e2a\u5355\u8bcd\u8fb9\u754c\u3002\u8fd9\u662f\u4e2a\u8d85\u51fa replace \u80fd\u529b\u7684\u5de5\u4f5c\uff09\u3002\n\u53e6\u4e00\u4e2a\u5e38\u89c1\u4efb\u52a1\u662f\u4ece\u4e00\u4e2a\u5b57\u7b26\u4e32\u4e2d\u5220\u9664\u5355\u4e2a\u5b57\u7b26\u6216\u7528\u53e6\u4e00\u4e2a\u5b57\u7b26\u6765\u66ff\u4ee3\u5b83\u3002\u4f60\u4e5f\u8bb8\u53ef\u4ee5\u7528 re.sub(&#8216;\\n&#8217;,&#8217; &#8216;, s) \u8fd9\u6837\u6765\u5b9e\u73b0\uff0c\u4f46 translate() \u80fd\u591f\u5b9e\u73b0\u8fd9\u4e24\u4e2a\u4efb\u52a1\uff0c\u800c\u4e14\u6bd4\u4efb\u4f55\u6b63\u5219\u8868\u8fbe\u5f0f\u64cd\u4f5c\u8d77\u6765\u66f4\u5feb\u3002 \uff08translate \u9700\u8981\u914d\u5408 string.maketrans \u4f7f\u7528\u3002\u4f8b\u5982\uff1aimport string \u540e &#8216;a1b3&#8217;.translate(string.maketrans(&#8216;ab&#8217;, &#8216;cd&#8217;)) \uff09<\/p>\n<p>&nbsp;<\/p>\n<p>\u603b\u4e4b\uff0c\u5728\u4f7f\u7528 re \u6a21\u5757\u4e4b\u524d\uff0c\u5148\u8003\u8651\u4e00\u4e0b\u4f60\u7684\u95ee\u9898\u662f\u5426\u53ef\u4ee5\u7528\u66f4\u5feb\u3001\u66f4\u7b80\u5355\u7684\u5b57\u7b26\u4e32\u65b9\u6cd5\u6765\u89e3\u51b3\u3002<\/p>\n<p><a id=\"match.28.29_vs_search.28.29\" name=\"match.28.29_vs_search.28.29\"><\/a><\/p>\n<h4>match() vs search()<\/h4>\n<p>match() \u51fd\u6570\u53ea\u68c0\u67e5 RE \u662f\u5426\u5728\u5b57\u7b26\u4e32\u5f00\u59cb\u5904\u5339\u914d\uff0c\u800c search() \u5219\u662f\u626b\u63cf\u6574\u4e2a\u5b57\u7b26\u4e32\u3002\u8bb0\u4f4f\u8fd9\u4e00\u533a\u522b\u662f\u91cd\u8981\u7684\u3002\u8bb0\u4f4f\uff0cmatch() \u53ea\u62a5\u544a\u4e00\u6b21\u6210\u529f\u7684\u5339\u914d\uff0c\u5b83\u5c06\u4ece 0 \u5904\u5f00\u59cb\uff1b\u5982\u679c\u5339\u914d\u4e0d\u662f\u4ece 0 \u5f00\u59cb\u7684\uff0cmatch() \u5c06\u4e0d\u4f1a\u62a5\u544a\u5b83\u3002<\/p>\n<pre>#!python\n>>> print re.match('super', 'superstition').span()\n(0, 5)\n>>> print re.match('super', 'insuperable')\nNone<\/pre>\n<p>\u53e6\u4e00\u65b9\u9762\uff0csearch() \u5c06\u626b\u63cf\u6574\u4e2a\u5b57\u7b26\u4e32\uff0c\u5e76\u62a5\u544a\u5b83\u627e\u5230\u7684\u7b2c\u4e00\u4e2a\u5339\u914d\u3002<\/p>\n<pre>#!python\n>>> print re.search('super', 'superstition').span()\n(0, 5)\n>>> print re.search('super', 'insuperable').span()\n(2, 7)<\/pre>\n<p>\u6709\u65f6\u4f60\u53ef\u80fd\u503e\u5411\u4e8e\u4f7f\u7528 re.match()\uff0c\u53ea\u5728RE\u7684\u524d\u9762\u90e8\u5206\u6dfb\u52a0 .* \u3002\u8bf7\u5c3d\u91cf\u4e0d\u8981\u8fd9\u4e48\u505a\uff0c\u6700\u597d\u91c7\u7528 re.search() \u4ee3\u66ff\u4e4b\u3002\u6b63\u5219\u8868\u8fbe\u5f0f\u7f16\u8bd1\u5668\u4f1a\u5bf9 REs \u505a\u4e00\u4e9b\u5206\u6790\u4ee5\u4fbf\u53ef\u4ee5\u5728\u67e5\u627e\u5339\u914d\u65f6\u63d0\u9ad8\u5904\u7406\u901f\u5ea6\u3002\u4e00\u4e2a\u90a3\u6837\u7684\u5206\u6790\u673a\u4f1a\u6307\u51fa\u5339\u914d\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\u662f\u4ec0\u4e48\uff1b\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u6a21\u5f0f Crow \u5fc5\u987b\u4ece &#8220;C&#8221; \u5f00\u59cb\u5339\u914d\u3002\u5206\u6790\u673a\u53ef\u4ee5\u8ba9\u5f15\u64ce\u5feb\u901f\u626b\u63cf\u5b57\u7b26\u4e32\u4ee5\u627e\u5230\u5f00\u59cb\u5b57\u7b26\uff0c\u5e76\u53ea\u5728 &#8220;C&#8221; \u88ab\u53d1\u73b0\u540e\u624d\u5f00\u59cb\u5168\u90e8\u5339\u914d\u3002<\/p>\n<p>\u6dfb\u52a0 .* \u4f1a\u4f7f\u8fd9\u4e2a\u4f18\u5316\u5931\u8d25\uff0c\u8fd9\u5c31\u8981\u626b\u63cf\u5230\u5b57\u7b26\u4e32\u5c3e\u90e8\uff0c\u7136\u540e\u56de\u6eaf\u4ee5\u627e\u5230 RE \u5269\u4f59\u90e8\u5206\u7684\u5339\u914d\u3002\u4f7f\u7528 re.search() \u4ee3\u66ff\u3002<\/p>\n<p><a id=\".E8.B4.AA.E5.A9.AA_vs_.E4.B8.8D.E8.B4.AA.E5.A9.AA\" name=\".E8.B4.AA.E5.A9.AA_vs_.E4.B8.8D.E8.B4.AA.E5.A9.AA\"><\/a><\/p>\n<h4>\u00a0\u8d2a\u5a6a vs \u4e0d\u8d2a\u5a6a<\/h4>\n<p>\u5f53\u91cd\u590d\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u65f6\uff0c\u5982\u7528 a<em>\uff0c\u64cd\u4f5c\u7ed3\u679c\u662f\u5c3d\u53ef\u80fd\u591a\u5730\u5339\u914d\u6a21\u5f0f\u3002\u5f53\u4f60\u8bd5\u7740\u5339\u914d\u4e00\u5bf9\u5bf9\u79f0\u7684\u5b9a\u754c\u7b26\uff0c\u5982 HTML \u6807\u5fd7\u4e2d\u7684\u5c16\u62ec\u53f7\u65f6\u8fd9\u4e2a\u4e8b\u5b9e\u7ecf\u5e38\u56f0\u6270\u4f60\u3002\u5339\u914d\u5355\u4e2a HTML \u6807\u5fd7\u7684\u6a21\u5f0f\u4e0d\u80fd\u6b63\u5e38\u5de5\u4f5c\uff0c\u56e0\u4e3a .<\/em> \u7684\u672c\u8d28\u662f\u201c\u8d2a\u5a6a\u201d\u7684<\/p>\n<pre>#!python\n>>> s = '<html><head><title>Title<\/title>'\n>>> len(s)\n32\n>>> print re.match('<.*>', s).span()\n(0, 32)\n>>> print re.match('<.*>', s).group()\n<html><head><title>Title<\/title><\/pre>\n<p>RE \u5339\u914d \u5728 &#8220;<code>&lt;html&gt;<\/code>&#8221; \u4e2d\u7684 &#8220;<\"\uff0c.<em> \u6d88\u8017\u6389\u5b57\u7b26\u4e32\u7684\u5269\u4f59\u90e8\u5206\u3002\u5728 RE \u4e2d\u4fdd\u6301\u66f4\u591a\u7684\u5de6\uff0c\u867d\u7136 > \u4e0d\u80fd\u5339\u914d\u5728\u5b57\u7b26\u4e32\u7ed3\u5c3e\uff0c\u56e0\u6b64\u6b63\u5219\u8868\u8fbe\u5f0f\u5fc5\u987b\u4e00\u4e2a\u5b57\u7b26\u4e00\u4e2a\u5b57\u7b26\u5730\u56de\u6eaf\uff0c\u76f4\u5230\u5b83\u627e\u5230 > \u7684\u5339\u914d\u3002\u6700\u7ec8\u7684\u5339\u914d\u4ece &#8220;<html\" \u4e2d\u7684 \"<\" \u5230 \"<\/title>&#8221; \u4e2d\u7684 &#8220;>&#8221;,\u8fd9\u5e76\u4e0d\u662f\u4f60\u6240\u60f3\u8981\u7684\u7ed3\u679c\u3002\n\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u89e3\u51b3\u65b9\u6848\u662f\u4f7f\u7528\u4e0d\u8d2a\u5a6a\u7684\u9650\u5b9a\u7b26 <\/em>?\u3001+?\u3001?? \u6216 {m,n}?\uff0c\u5c3d\u53ef\u80fd\u5339\u914d\u5c0f\u7684\u6587\u672c\u3002\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u91cc\uff0c &#8220;>&#8221; \u5728\u7b2c\u4e00\u4e2a &#8220;<\" \u4e4b\u540e\u88ab\u7acb\u5373\u5c1d\u8bd5\uff0c\u5f53\u5b83\u5931\u8d25\u65f6\uff0c\u5f15\u64ce\u4e00\u6b21\u589e\u52a0\u4e00\u4e2a\u5b57\u7b26\uff0c\u5e76\u5728\u6bcf\u6b65\u91cd\u8bd5 \">&#8220;\u3002\u8fd9\u4e2a\u5904\u7406\u5c06\u5f97\u5230\u6b63\u786e\u7684\u7ed3\u679c\uff1a<\/p>\n<pre>#!python\n>>> print re.match('<.*?>', s).group()\n<html><\/pre>\n<p>\u6ce8\u610f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u5206\u6790 HTML \u6216 XML \u662f\u75db\u82e6\u7684\u3002\u53d8\u5316\u6df7\u4e71\u7684\u6a21\u5f0f\u5c06\u5904\u7406\u5e38\u89c1\u60c5\u51b5\uff0c\u4f46 HTML \u548c XML \u5219\u662f\u660e\u663e\u4f1a\u6253\u7834\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u7279\u6b8a\u60c5\u51b5\uff1b\u5f53\u4f60\u7f16\u5199\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u53bb\u5904\u7406\u6240\u6709\u53ef\u80fd\u7684\u60c5\u51b5\u65f6\uff0c\u6a21\u5f0f\u5c06\u53d8\u5f97\u975e\u5e38\u590d\u6742\u3002\u8c61\u8fd9\u6837\u7684\u4efb\u52a1\u7528 HTML \u6216 XML \u89e3\u6790\u5668\u3002<\/p>\n<p><em><strong>\u7c97\u4f53\u6587\u5b57<\/strong><\/em>\u7c97\u4f53\u6587\u5b57&#8217;<\/p>\n<hr \/>\n<p><a id=\".E4.B8.8D.E7.94.A8_re.VERBOSE\" name=\".E4.B8.8D.E7.94.A8_re.VERBOSE\"><\/a><\/p>\n<h4>\u00a0\u4e0d\u7528 re.VERBOSE<\/h4>\n<p>\u73b0\u5728\u4f60\u53ef\u80fd\u6ce8\u610f\u5230\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u8868\u793a\u662f\u5341\u5206\u7d27\u51d1\uff0c\u4f46\u5b83\u4eec\u975e\u5e38\u4e0d\u597d\u8bfb\u3002\u4e2d\u5ea6\u590d\u6742\u7684 REs \u53ef\u4ee5\u53d8\u6210\u53cd\u659c\u6760\u3001\u5706\u62ec\u53f7\u548c\u5143\u5b57\u7b26\u7684\u957f\u957f\u96c6\u5408\uff0c\u4ee5\u81f4\u4e8e\u4f7f\u5b83\u4eec\u5f88\u96be\u8bfb\u61c2\u3002\n\u5728\u8fd9\u4e9b REs \u4e2d\uff0c\u5f53\u7f16\u8bd1\u6b63\u5219\u8868\u8fbe\u5f0f\u65f6\u6307\u5b9a re.VERBOSE \u6807\u5fd7\u662f\u6709\u5e2e\u52a9\u7684\uff0c\u56e0\u4e3a\u5b83\u5141\u8bb8\u4f60\u53ef\u4ee5\u7f16\u8f91\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u683c\u5f0f\u4f7f\u4e4b\u66f4\u6e05\u695a\u3002\nre.VERBOSE \u6807\u5fd7\u6709\u8fd9\u4e48\u51e0\u4e2a\u4f5c\u7528\u3002\u5728\u6b63\u5219\u8868\u8fbe\u5f0f\u4e2d\u4e0d\u5728\u5b57\u7b26\u7c7b\u4e2d\u7684\u7a7a\u767d\u7b26\u88ab\u5ffd\u7565\u3002\u8fd9\u5c31\u610f\u5473\u7740\u8c61 dog | cat \u8fd9\u6837\u7684\u8868\u8fbe\u5f0f\u548c\u53ef\u8bfb\u6027\u5dee\u7684 dog|cat \u76f8\u540c\uff0c\u4f46 [a b] \u5c06\u5339\u914d\u5b57\u7b26 &#8220;a&#8221;\u3001&#8221;b&#8221; \u6216 \u7a7a\u683c\u3002\u53e6\u5916\uff0c\u4f60\u4e5f\u53ef\u4ee5\u628a\u6ce8\u91ca\u653e\u5230 RE \u4e2d\uff1b\u6ce8\u91ca\u662f\u4ece &#8220;#&#8221; \u5230\u4e0b\u4e00\u884c\u3002\u5f53\u4f7f\u7528\u4e09\u5f15\u53f7\u5b57\u7b26\u4e32\u65f6\uff0c\u53ef\u4ee5\u4f7f REs \u683c\u5f0f\u66f4\u52a0\u5e72\u51c0\uff1a<\/p>\n<pre>#!python\npat = re.compile(r\"\"\"\n\\s*                 # Skip leading whitespace\n(?P<header>[^:]+)   # Header name\n\\s*\u00a0:               # Whitespace, and a colon\n(?P<value>.*?)      # The header's value -- *? used to\n# lose the following trailing whitespace\n\\s*$                # Trailing whitespace to end-of-line\n\"\"\", re.VERBOSE)<\/pre>\n<p>\u8fd9\u4e2a\u8981\u96be\u8bfb\u5f97\u591a\uff1a<\/p>\n<pre>#!python\npat = re.compile(r\"\\s*(?P<header>[^:]+)\\s*:(?P<value>.*?)\\s*$\")<\/pre>\n<p><a id=\".E5.8F.8D.E9.A6.88\" name=\".E5.8F.8D.E9.A6.88\"><\/a><\/p>\n<h3>\u53cd\u9988<\/h3>\n<p>\u6b63\u5219\u8868\u8fbe\u5f0f\u662f\u4e00\u4e2a\u590d\u6742\u7684\u4e3b\u9898\u3002\u672c\u6587\u80fd\u5426\u6709\u52a9\u4e8e\u4f60\u7406\u89e3\u5462\uff1f\u54ea\u4e9b\u90e8\u5206\u662f\u5426\u4e0d\u6e05\u6670\uff0c\u6216\u5728\u8fd9\u513f\u6ca1\u6709\u627e\u5230\u4f60\u6240\u9047\u5230\u7684\u95ee\u9898\uff1f\u5982\u679c\u662f\u90a3\u6837\u7684\u8bdd\uff0c\u8bf7\u5c06\u5efa\u8bae\u53d1\u7ed9\u4f5c\u8005\u4ee5\u4fbf\u6539\u8fdb\u3002<\/p>\n<p>\u63cf\u8ff0\u6b63\u5219\u8868\u8fbe\u5f0f\u6700\u5168\u9762\u7684\u4e66\u975eJeffrey Friedl \u5199\u7684\u300a\u7cbe\u901a\u6b63\u5219\u8868\u8fbe\u5f0f\u300b\u83ab\u5c5e\uff0c\u8be5\u4e66\u7531O&#8217;Reilly \u51fa\u7248\u3002\u53ef\u60dc\u8be5\u4e66\u53ea\u4e13\u6ce8\u4e8e Perl \u548c Java \u98ce\u683c\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\uff0c\u4e0d\u542b\u4efb\u4f55 Python \u6750\u6599\uff0c\u6240\u4ee5\u4e0d\u8db3\u4ee5\u7528\u4f5cPython\u7f16\u7a0b\u65f6\u7684\u53c2\u8003\u3002\uff08\u7b2c\u4e00\u7248\u5305\u542b\u6709 Python \u73b0\u5df2\u8fc7\u65f6\u7684 regex \u6a21\u5757\uff0c\u81ea\u7136\u7528\u5904\u4e0d\u5927\uff09\u3002<\/p>\n<p>\u300a\u7cbe\u901a\u6b63\u5219\u8868\u8fbe\u5f0f\u300b\u7b2c\u4e09\u7248\u5df2\u7ecf\u6709\u90e8\u5206\u6b63\u5219\u8868\u8fbe\u5f0f\u4f7f\u7528python\u8bf4\u660e\uff0c\u53e6\u5916PHP\u98ce\u683c\u7684\u66f4\u662f\u72ec\u7acb\u4e00\u4e2a\u7ae0\u8282\u8bf4\u660e\u3002&#8211;why<\/p>","protected":false},"excerpt":{"rendered":"<p>\u6458\u8981 \u672c\u6587\u662f\u901a\u8fc7Python\u7684 re \u6a21\u5757\u6765\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u4e00\u4e2a\u5165\u95e8\u6559\u7a0b\uff0c\u548c\u5e93\u53c2\u8003\u624b\u518c\u7684\u5bf9\u5e94\u7ae0\u8282\u76f8\u6bd4\uff0c\u66f4\u4e3a\u6d45\u663e\u6613\u61c2\u3001\u5faa\u5e8f\u6e10\u8fdb\u3002 \u672c\u6587\u53ef\u4ee5\u4ece <a href=\"http:\/\/www.amk.ca\/python\/howto&#46;&#46;&#038;#46\">http:\/\/www.amk.ca\/python\/howto&#46;&#46;&#038;#46<\/a>;<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,274],"tags":[],"class_list":["post-779","post","type-post","status-publish","format-standard","hentry","category-linux","category-python"],"_links":{"self":[{"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/posts\/779","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/comments?post=779"}],"version-history":[{"count":3,"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/posts\/779\/revisions"}],"predecessor-version":[{"id":781,"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/posts\/779\/revisions\/781"}],"wp:attachment":[{"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/media?parent=779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/categories?post=779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nick.txtcc.com\/index.php\/wp-json\/wp\/v2\/tags?post=779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}