<!DOCTYPE html>
<!-- saved from url=(0060)https://developers.google.com/edu/python/regular-expressions -->
<html lang="en" class="chekov"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><script type="text/javascript" id="www-widgetapi-script" src="./Python Regular Expressions _ Google for Education _ Google Developers_files/www-widgetapi.js" async=""></script><script type="text/javascript" async="" src="./Python Regular Expressions _ Google for Education _ Google Developers_files/linkid.js"></script><script async="" src="./Python Regular Expressions _ Google for Education _ Google Developers_files/analytics.js"></script><script src="./Python Regular Expressions _ Google for Education _ Google Developers_files/cb=gapi.loaded_0" async=""></script><script>var a=window.devsite||{};window.devsite=a;a.readyCallbacks=[];window.devsite.readyCallbacks=a.readyCallbacks;a.ready=function(b){a.readyCallbacks.push(b)};window.devsite.ready=a.ready;
</script><meta name="xsrf_token" content="6u6noAUtM9gf_FTtObKDZfZQZogNA3O80K5EisgYPtY6MTQ4NzM5NDM0NDgzNzUxMA"><link rel="canonical" href="https://developers.google.com/edu/python/regular-expressions"><link rel="alternate" href="https://developers.google.com/edu/python/regular-expressions" hreflang="en"><link rel="alternate" href="https://developers.google.cn/edu/python/regular-expressions" hreflang="en-cn"><link rel="alternate" href="https://developers.google.com/edu/python/regular-expressions" hreflang="x-default"><link rel="shortcut icon" href="https://developers.google.com/_static/93bc4b4492/images/favicon.png"><link rel="apple-touch-icon" href="https://developers.google.com/_static/93bc4b4492/images/touch-icon.png"><meta name="viewport" content="width=device-width, initial-scale=1"><style>@-webkit-keyframes gb__a{0%{opacity:0}50%{opacity:1}}@keyframes gb__a{0%{opacity:0}50%{opacity:1}}#gbsfw{min-width:400px;overflow:visible}.gb_Ub,#gbsfw.gb_g{display:block;outline:none}#gbsfw.gb_ra iframe{display:none}.gb_Vb{padding:118px 0;text-align:center}.gb_Wb{background:no-repeat center 0;color:#aaa;font-size:13px;line-height:20px;padding-top:76px;background-image:-webkit-image-set(url('//ssl.gstatic.com/gb/images/a/f5cdd88b65.png') 1x,url('//ssl.gstatic.com/gb/images/a/133fc21e88.png') 2x)}.gb_Wb a{color:#4285f4;text-decoration:none}.gb_7a{display:none!important}.gb_8a{visibility:hidden}.gb_Oc{display:inline-block;padding:0 0 0 15px;vertical-align:middle}.gb_Oc:first-child,#gbsfw:first-child+.gb_Oc{padding-left:0}.gb_zc{position:relative}.gb_b{display:inline-block;outline:none;vertical-align:middle;-webkit-border-radius:2px;border-radius:2px;-webkit-box-sizing:border-box;box-sizing:border-box;height:30px;width:30px;color:#000;cursor:pointer;text-decoration:none}#gb#gb a.gb_b{color:#000;cursor:pointer;text-decoration:none}.gb_kb{border-color:transparent;border-bottom-color:#fff;border-style:dashed dashed solid;border-width:0 8.5px 8.5px;display:none;position:absolute;left:6.5px;top:37px;z-index:1;height:0;width:0;-webkit-animation:gb__a .2s;animation:gb__a .2s}.gb_lb{border-color:transparent;border-style:dashed dashed solid;border-width:0 8.5px 8.5px;display:none;position:absolute;left:6.5px;z-index:1;height:0;width:0;-webkit-animation:gb__a .2s;animation:gb__a .2s;border-bottom-color:#ccc;border-bottom-color:rgba(0,0,0,.2);top:36px}x:-o-prefocus,div.gb_lb{border-bottom-color:#ccc}.gb_ha{background:#fff;border:1px solid #ccc;border-color:rgba(0,0,0,.2);color:#000;-webkit-box-shadow:0 2px 10px rgba(0,0,0,.2);box-shadow:0 2px 10px rgba(0,0,0,.2);display:none;outline:none;overflow:hidden;position:absolute;right:0;top:44px;-webkit-animation:gb__a .2s;animation:gb__a .2s;-webkit-border-radius:2px;border-radius:2px;-webkit-user-select:text}.gb_Oc.gb_g .gb_kb,.gb_Oc.gb_g .gb_lb,.gb_Oc.gb_g .gb_ha,.gb_g.gb_ha{display:block}.gb_Oc.gb_g.gb_Be .gb_kb,.gb_Oc.gb_g.gb_Be .gb_lb{display:none}.gb_Ce{position:absolute;right:0;top:44px;z-index:-1}.gb_bb .gb_kb,.gb_bb .gb_lb,.gb_bb .gb_ha{margin-top:-10px}.gb_Eb .gb_lb{border:0;border-left:1px solid rgba(0,0,0,.2);border-top:1px solid rgba(0,0,0,.2);height:14px;width:14px;-webkit-transform:rotate(45deg);transform:rotate(45deg)}.gb_Eb .gb_kb{border:0;border-left:1px solid rgba(0,0,0,.2);border-top:1px solid rgba(0,0,0,.2);height:14px;width:14px;-webkit-transform:rotate(45deg);transform:rotate(45deg);border-color:#fff;background:#fff}.gb_Me ::-webkit-scrollbar{height:15px;width:15px}.gb_Me ::-webkit-scrollbar-button{height:0;width:0}.gb_Me ::-webkit-scrollbar-thumb{background-clip:padding-box;background-color:rgba(0,0,0,.3);border:5px solid transparent;-webkit-border-radius:10px;border-radius:10px;min-height:20px;min-width:20px;height:5px;width:5px}.gb_Me ::-webkit-scrollbar-thumb:hover,.gb_Me ::-webkit-scrollbar-thumb:active{background-color:rgba(0,0,0,.4)}.gb_fa .gb_b{background-position:-35px -311px;opacity:.55}.gb_ga .gb_fa .gb_b{background-position:-35px -311px}.gb_X .gb_fa .gb_b{background-position:-60px -1675px;opacity:1}.gb_ha.gb_ia{min-height:196px;overflow-y:auto;width:320px}.gb_ja{-webkit-transition:height .2s ease-in-out;transition:height .2s ease-in-out}.gb_ka{background:#fff;margin:0;min-height:100px;padding:28px;padding-right:27px;text-align:left;white-space:normal;width:265px}.gb_la{background:#f5f5f5;cursor:pointer;height:40px;overflow:hidden}.gb_ma{position:relative}.gb_la{display:block;line-height:40px;text-align:center;width:320px}.gb_ma{display:block;line-height:40px;text-align:center}.gb_ma.gb_na{line-height:0}.gb_la,.gb_la:visited,.gb_la:active,.gb_ma,.gb_ma:visited{color:#737373;text-decoration:none}.gb_ma:active{color:#737373}#gb a.gb_la,#gb a.gb_la:visited,#gb a.gb_la:active,#gb a.gb_ma,#gb a.gb_ma:visited{color:#737373;text-decoration:none}#gb a.gb_ma:active{color:#737373}.gb_ma,.gb_ka{display:none}.gb_da,.gb_da+.gb_ma,.gb_oa .gb_ma,.gb_oa .gb_ka{display:block}.gb_ma:hover,.gb_ma:active,#gb a.gb_ma:hover,#gb a.gb_ma:active{text-decoration:underline}.gb_ma{border-bottom:1px solid #ebebeb;left:28px;width:264px}.gb_oa .gb_la{display:none}.gb_ma:last-child{border-bottom-width:0}.gb_pa .gb_O{display:initial}.gb_pa.gb_qa{height:100px;text-align:center}.gb_pa.gb_qa img{padding:34px 0;height:32px;width:32px}.gb_pa .gb_3{background-image:url('//ssl.gstatic.com/gb/images/v1_76783e20.png');-webkit-background-size:92px 2541px;background-size:92px 2541px;background-position:0 -690px}.gb_pa .gb_3+img{border:0;margin:8px;height:48px;width:48px}.gb_pa div.gb_ra{background:#ffa;-webkit-border-radius:5px;border-radius:5px;padding:5px;text-align:center}.gb_pa.gb_sa,.gb_pa.gb_ta{padding-bottom:0}.gb_pa.gb_ua,.gb_pa.gb_ta{padding-top:0}.gb_pa.gb_ta a,.gb_pa.gb_ua a{top:0}.gb_va .gb_la{margin-top:0;position:static}.gb_wa{display:inline-block}.gb_xa{margin:-12px 28px 28px;position:relative;width:264px;-webkit-border-radius:2px;border-radius:2px;-webkit-box-shadow:0 1px 2px rgba(0,0,0,0.1),0 0 1px rgba(0,0,0,0.1);box-shadow:0 1px 2px rgba(0,0,0,0.1),0 0 1px rgba(0,0,0,0.1)}.gb_6{background-image:url('//ssl.gstatic.com/gb/images/v1_76783e20.png');-webkit-background-size:92px 2541px;background-size:92px 2541px;display:inline-block;margin:8px;vertical-align:middle;height:64px;width:64px}.gb_ya{color:#262626;display:inline-block;font:13px/18px Arial,sans-serif;margin-right:80px;padding:10px 10px 10px 0;vertical-align:middle;white-space:normal}.gb_za{font:16px/24px Arial,sans-serif}.gb_Aa,#gb#gb .gb_Aa{color:#427fed;text-decoration:none}.gb_Aa:hover,#gb#gb .gb_Aa:hover{text-decoration:underline}.gb_Ba .gb_ka{position:relative}.gb_Ba .gb_O{position:absolute;top:28px;left:28px}.gb_la.gb_Ca{display:none;height:0}.gb_Ba .gb_5{position:absolute;width:86px;top:112px;left:28px;margin:8px 2px}.gb_N .gb_fa .gb_b::before,.gb_N.gb_ga .gb_fa .gb_b::before{left:-35px;top:-311px}.gb_N.gb_X .gb_fa .gb_b::before{left:-60px;top:-1675px}.gb_Eb .gb_la{position:relative}.gb_fa .gb_b:hover,.gb_fa .gb_b:focus{opacity:.85}.gb_X .gb_fa .gb_b:hover,.gb_X .gb_fa .gb_b: